Reference Articles
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Balsom, P.D., K. Soderlund, B. Sjodin and B. Ekblom. Skeletal muscle metabolism during short duration high-intensity exercise: influence of creatine supplementation. Acta Physiol Scand 154: 303-310, 1995.
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Birch, R., D. Noble, and P.L. Greenhaff. The influence of dietary creatine supplementation on performance during repeated bouts of maximal isokinetic cycling in man. Eur. J. Appl. Physio. 64:268-270, 1994.
Cooke, W.H., P.W. Grandjean, and W.S. Barnes. Effect of oral creatine supplementation on power output and fatigue during bicycle ergometry. J. Appl. Physiol. 78(2): 670-673, 1995.
Greenhaff, P.L. Creatine and its application as an ergogenic aid. Int. J. of Sport Nutrition, 5: S100-S110, 1995.
Greenhaff, P.L., K. Bodin, D. Soderlund, and E. Hultman. Effect of oral creatine supplementation on skeletal muscle phosphocreatine resynthesis. Endocrinol. Metab. 29: E725-E730, 1994.
Greenhaff, P.L., A. Casey, A.H. Short, R. Harris, K Soderlund, and E. Hultman. Influence of oral creatine supplementation of muscle torque during repeated bouts of maximal voluntary exercise in man. Clinical Science. 84: 565-571, 1993.
Harris, R.C., K Soderlund and E. Hultman. Elevation of creatine in resting and exercised muscle of normal subjects by creatine supplementation. Clinical Science. 83: 367-374, 1992.
Hultman, E., and P.L. Greenhaff. Creatine ingestion and exercise performance in humans. Nutrition Notes. 14-15, August 1995.
Stroud, M.A., D. Holliman, D. Bell, A.L. Green, I.A. Macdonald, and P.L. Greenhaff. Effect of oral creatine supplementation on respiratory gas exchange and blood lactate accumulation during steady-state incremental treadmill exercise and recovery in man. Clinical Science. 87: 707-710, 1994.
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Researcher: Greenhaff, P.L. Article Title : Creatine and its application as an ergogenic aid Journal or Magazine: International Journal of Sport Nutrition (1995) 5 : S100--S110
Researchers :Greenhaff, PL; Casey, A; Short, AH; Harris,RC; Soderlund, K and Hultman, E Article Title: Influence of oral creatine supplementation on muscle torque during repeated bouts of maximal voluntary exercise in man Journal or Magazine: Clinical Science (1993) 84:565--571
Researchers: Harridge SDR, Balsom PD, Sodderlund K. Article Title: Creatine supplementation and electrically evoked human muscle fatigue Journal or Magazine; Clinical Science 1994:87 (Suppl.) : 124
Researcher : Kozalka TR. Andrew CL. Article Title: Effect of insulin on the uptake of creatine-1-14C by skeletal muscle Journal or Magazine: Proc Soc Exp Biol Med 1972: 139: 1265-71
Researchers: Bessman SP, Savabi F Article Title : The role of the phosphocreatine energy shuttle in exercise and muscle hypertrophy. Journal or Magazine: International series on sport sciences, vol. 21 Champaign: human Kinetics. 1988:167-78
Researchers : Harris R, Soderlund K, Hultman E. Article Title: Elevation of creatine in resting and exercise muscles of normal subjects by creatine supplementation Journal or Magazine: Clinical Science 1992; 83; 367-74
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Researchers: Balsom PD, Ekblom B, Soderlund K, et al. Article Title : Creatine supplemntation and dynamic high-intensity intermittent exercise Journal or Magazine: Scand J Med Sci sports 1993; 3:143-9
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Researchers: Katz, A., K, Sahlin, and J. Henriksson Article Title: Muscle ATP turnpver rate during isometric contraction in humans Journal or Magazine: J.Appl. Physiol. 60. 1839-1842, 1986
Researchers: Harris,R.C., M.Viru,P.L. Greenhaff, and E. Hultman Article Title: The effect of oral creatine supplementation on running performance during maximal short term exrcise in man Journal or Magazine: J. Physiol. Lond. 467:74, 1993.
Balsom, P.D., B. Ekblom, K. Soderlund, B. Sjodin, and E. Hultman. Creatine supplementation and dynamic high-intensity intermittent exercise. Scand. J. Med. Sci. Sports. 1993;3:143-149.
Balsom, P.D., S.D.R. Harridge, K. Soderlund, B. Sjodin, and B. Ekblom. Creatine supplementation per se does not enhance endurance performance. Acta Physiol. Scand. 1993;149:521-523.
Birch, R., D. Novel, and P.L. Greenhaff. The influence of dietary creatine supplementation on performance during repeated bouts of maximal isokinetic cycling in man. Eur. J. Appl. Physiol. 1994;69:268-270.
Casey, A., D. Constantin-Teodosiu, S. Howell. E. Hultman and P.L. Greenhaff. Creatine ingestion faborably affects performance and muscle metabolism diurng maximal exercise in humans. Am. J. Physiol. 1996;271, E31-E37.
Casey, A., D. Constantin-Teodosiu, s. Howell. E. Hultman and P.L. Greenhaff. Metabolic response of type I and II muscle fibers during repeated bouts of maximal exercise in humans. Am. J. Physiol. 1996;271, E38-E43.
Clark J.F. Uses of creatine phosphate and creatine supplementation for the athlete. Pp 217-225. Creatine and creatine phosphate: Scientific and clinical perspectives. Eds. M.A. Conway and J.F. Clark, Academic Press, 1996.
Clark J.F., J. Odoom, I. Tracey, J. Dunn, E.A. Boehm, G. Paternostro, and G.K. Radda. Experimental observations of creatine and creatine phosphate metabolism. Pp 33-50. Creatine and creatine phosphate: Scientific and clinical perspectives. Eds. M.A. Conway and J.F. Clark, Academic Press, 1996.
Conway M.A., B. Rajagopalan, and G.K. Radda. Skeletal muscle metabolism in heart failure. Pp 161-184. Creatine and creatine phosphate: Scientific and clinical perspectives. Eds. M.A. Conway and J.F. Clark, Academic Press, 1996.
Conway M.A., R. Ouwerkerk, B. Rajagopalan, and G.K. Radda. Creatine phosphate: in vivo human cardiac metabolism studied by magnetic resonance spectroscopy. Pp 127-160. Creatine and creatine phosphate: Scientific and clinical perspectives. Eds. M.A. Conway and J.F. Clark, Academic Press, 1996.
Ernest, C.P., P.G. Snell. R. Rodriguez. A.L. Almada and T.L. Mitchell. The effect of creatine monohydrate ingestion on anaerobic power indices, muscular strength and body composition. Acta. Physiol. Scand. 1995; 153: 207-209.
Fitch, CD and RP Shields. Creatine metabolism in skeletal muscle. I. Creatine movement across muscle membranes. J. Biol. Chem. 1966;241:3611-3614.
Green, A.L., E. Hultman, I.A. Macdonald, D.A. Sewell and P.L. Greenhaff. Carbohydrate ingestion augments Skeletal muscle creatine accumulation during creatine supplementation in man. Am J. Physiol. In press.
Greenhaff, P.L., A. Casey, A.H. Short, R. Harris, K. Soderlund and E. Hultman. Influence of oral creatine supplementation of muscle torque during repeated bouts of maximal voluntary exercise in man. Clin. Sci. 1993;84:565-571.
Greenhaff, P.L., K. Bodin, K. Soderlund, E. Hultman. Effect of oral creatine supplementation on skeletal muscle phosphocreatine resynthesis. Am J. Physiol. 1994;266:E725-E730.
Greenhaff, P.L., K. Bodin, R.C. Harris, E. Hultman, D.A. Jones, D.B. McIntyre, K. Soderlund and D.L. Turner. The influence of oral creatine supplementation on muscle phosphocreatine resynthesis following intense contraction in man. J. Physiol. 1993;467:75P.
Harris, R.C., K. Soderlund and E. Hultman. Elevation of creatine in resting and exercised muscle of normal subjects by creatine supplementation. Clin. Sci. 1992;83:367-374.
Harris, R.C., M. Viru, P.L. Greenhaff, and E. Hultman. The effect of oral creatine supplementation on running performance during maximal short term exercise in man. J. Physiol. 1993;467:74P.
Hultman, E., K. Soderlund, J.A. Timmons, G. Cederblad and P.L. Greenhaff. Muscle creatine loading in man. J. Applied Physiol. 1996;81;232-237.
Saks, V.A., and E. Strumia. Phosphocreatine: molecular and cellular aspects of the mechanism of cardioprotective action. Curr. Ther. Res. 1993;53:565-598.
Saks, V.A., S.A. Javadov, E. Pozin, and A.N. Preobrazhensky. Biochemical basis of the protective action of phosphocreatine on the ischemic myocardium. In Creatine phosphate: Biochemistry, Pharmacology, and Clinical Efficiency. 1987 Eds V.A. Saks, Y.G. Bobkov, and E. Strumia. Edizoni Minerva Medica, Torino Italy. 270-273.
Sipila, I, J. Rapola, O. Simell, and A. Vannas. Supplementary creatine as a treatment for gyrate atrophy of the choroid and retina. New. Eng. J. Med. 1981;304:867-870.
Trump M.E., G.J.F. Heigenhauser, C.T. Putman, and L.L. Spriet. Importance of muscle phosphocreatine during intermittent maximal cycling. J. Appl. Physiol. 1996;80: 1574-1580.
Wallimann, T., M. Wyss, D. Brdczka, K. Nicolay and H.M. Eppenberger. Intracellular compartmentation structure and function of creatine kinase isozymes in tissue with high and fluctuating energy demands: the phosphocreatine circuit for cellular energy homeostasis. Biochem. J. 1992;1102:21-40.
Creatine and Creatine Phosphate; Scientific and Clinical Perspectives. M.A. Conway and J.F. Clark. Academic Press (London 1996).
1 of 21 Marked Record TI: Effect of creatine on aerobic and anaerobic metabolism in skeletal muscle in swimmers AU: Thompson,-C.-H; Sanderson,-A.-L; Kemp,-G.-J; Dixon,-R.-M; Styles,-P; Taylor,-D.-J; Radda,-G.-K JN: British-journal-of-sports-medicine-(Oxford,-England); 30(3), Sept 1996, 222-225 Refs:21 IS: 0306-3674 PY: 1996 LA: English DT: Serial-Article LE: Advanced DE: swimming-; woman-; athlete-; creatine-; dietary-supplementation; muscle-metabolism SH: (408114) SWIMMING-NUTRITION; (931480) DRUGS-AND-DOPING-ERGOGENIC-AIDS-AMINO-ACID-SUPPLEMENTATION SC: 408114, 408; 931480, 931 AB: To examine the effect of a relatively low dose of creatine on skeletal muscle metabolism and oxygen supply in a group of training athletes. P magnetic resonance and near-infrared spectroscopy were used to study calf muscle metabolism in a group of 10 female members of a university swimming team. Studies were performed before and after a six week period of training during which they took either 2 g creatine daily or placebo. Calf muscle metabolism and creatine/choline ratios were studied in resting muscle, during plantar flexion exercise (10-15 min), and during recovery from exercise. There was no effect of creatine on metabolite ratios at rest or on metabolism during exercise and recovery from exercise. Muscle oxygen supply and exercise performance were not improved by creatine if compared to placebo treated subjects. Oral creatine supplementation at 2 g daily has no effect on muscle creatine concentration, muscle oxygen supply or muscle aerobic or anaerobic metabolism during endurance exercise
2 of 21 Marked Record TI: The influence of recovery duration on high-intensity exercise performance after oral creatine supplementation AU: Cooke,-W.-H SO: University Microfilms International, Ann Arbor, Mich, 1996, 2 microfiches (135 fr.) PY: 1996 NT: Thesis (Ph. D.) - Texas A & M University, 1995; Includes bibliography. LA: English DT: Thesis; Microform LE: Advanced DE: creatine-; exercise-; training-; adaptation-; recovery-; phosphocreatine-; man-; cycling-; bicycle-ergometry SH: (796127) CYCLING-PHYSIOLOGY; (981700) PHYSIOLOGY-EXERCISE-WARM-UP-AND-RECOVERY; (980382) PHYSIOLOGY-ENERGY-METABOLISM-PROTEINS-AMINO-ACIDS SC: 796127, 796; 981700, 981; 980382, 980 FRSH: (796127) CYCLISME-PHYSIOLOGIE; (981700)
3 of 21 Marked Record TI: The effects of creatine supplementation on total work output and metabolism during high-intensity intermittent exercise AU: Prevost,-M.-C SO: University Microfilms international, Ann Arbor, Mich, 1996, 2 microfiches (116 fr.) PY: 1996 NT: Thesis (Ph. D.) - The Louisiana State university and Agricultural and Mechanical College, 1995; Includes bibliography. LA: English DT: Thesis; Microform LE: Advanced DE: creatine-; exercise-; bicycle-ergometry; endurance-; adaptation-; achievement-; young-adult; man-; woman- SH: (982500) PHYSIOLOGY-FACTORS-AFFECTING-PERFORMANCE-NUTRITION; (981600) PHYSIOLOGY-EXERCISE-TESTING; (980382) PHYSIOLOGY-ENERGY-METABOLISM-PROTEINS-AMINO-ACIDS SC: 982500, 982; 981600, 981; 980382, 980 FRSH: (982500)
4 of 21 Marked Record TI: Effect of oral creatine supplementation on single-effort sprint performance in elite swimmers AU: Burke,-L.-M; Pyne,-D.-B; Telford,-R.-D JN: International-journal-of-sport-nutrition-(Champaign,-Ill.); 6(3), Sept 1996, 222-233 Refs:22 IS: 1050-1606 PY: 1996 LA: English DT: Serial-Article LE: Advanced DE: elite-athlete; man-; woman-; Australia-; sprint-swimming; creatine-; dietary-supplementation SH: (418114) SPRINT-SWIMMING-NUTRITION; (931480) DRUGS-AND-DOPING-ERGOGENIC-AIDS-AMINO-ACID-SUPPLEMENTATION SC: 418114, 418; 931480, 931 AB: Oral supplementation with creatine monohydrate (Cr.H2O) has been reported to increase muscle creatine phosphate levels. The aim of the present study was to determine the effect of such supplementation on performance of a single-effort sprint by elite swimmers. Thirty-two elite swimmers (M = 18, F = 14; age = 17-25 years) from the Australian Institute of Sport were tested on two occasions, 1 week apart. Tests performed were 25-m, 50-m, and 100-m maximal effort sprints (electronically timed with dive start, swimmers performing their best stroke), each with approximately 10 min active recovery. A 10-s maximal leg ergometry test was also undertaken. Swimmers were divided into two groups matched for sex, stroke/event, and sprint time over 50 m, and groups were randomly assigned to 5 days of Cr.H2O supplementation (4.day-1 X 5 g Cr.H2O + 2 g sucrose, n = 16) or placebo (4.day-1 X 5 g Polycose + 2 g sucrose, n = 16) prior to the second trial. Results revealed no significant differences between the group means for sprint times or between 10-s maximal leg ergometry power and work. This study does not support the hypothesis that creatine supplementation enhances single-effort sprint ability of elite swimmers FRSH: (418114)
5 of 21 Marked Record TI: The effect of oral creatine monohydrate supplementation on running velocity AU: Redondo,-D.-R; Dowling,-E.-A; Graham,-B.-L; Almada,-A.-L; Williams,-M.-H JN: International-journal-of-sport-nutrition-(Champaign,-Ill.); 6(3), Sept 1996, 213-221 Refs:22 IS: 1050-1606 PY: 1996 LA: English DT: Serial-Article LE: Advanced DE: soccer-; field-hockey; sprinting-; man-; woman-; athlete-; creatine-; dietary-supplementation SH: (740114) SPRINTING-NUTRITION; (931480) DRUGS-AND-DOPING-ERGOGENIC-AIDS-AMINO-ACID-SUPPLEMENTATION SC: 740114, 740; 931480, 931 AB: Creatine supplementation has been shown to augment muscle PCr content and increase the rate of ATP resynthesis. Thus, we hypothesized that creatine supplementation might enhance sprinting performance. Eighteen subjects completed both of two testing sessions (control and postsupplement) 1 week apart, wherein they sprinted three 60-m distance trials that were recorded with videotape. Following the control session, for 7 days, subjects in the treatment group ingested a creatine-glucose mixture, while the placebo group consumed a glucose powder, followed by the postsupplementation session. Velocities of the subjects through three testing zones within the 60-m sprint were calculated from the videotape. Resultant velocities were analyzed using a MANOVA with a 2 X 2 X 3 X 3 (Group X Session X Trial X Zone) design. Results indicated that there were no statistically significant main or interaction effects on velocity between groups for session, trial, or zone. These data do not support the hypothesis that supplementary creatine ingestion will enhance velocity during the early or latter segments of a 60-m sprint FRSH: (740114)
6 of 21 Marked Record TI: The role and application of dietary creatine supplementation in increasing physical performance capacity AU: Oopik,-V; Timpmann,-S; Medijainen,-L JN: Biology-of-sport-(Warsaw); 12(4), 1995, 197-212 Refs:49 IS: 0860-021X PY: 1995 LA: English LO: Estonian DT: Serial-Article LE: Advanced DE: exercise-; physical-fitness; aerobic-capacity; anaerobic-capacity; sport-; achievement-; creatine-; phosphocreatine-; diet-; nutrition-; energy-metabolism; muscle-protein; muscle-metabolism; endurance-; fatigue-; man-; animal-; research-; review- SH: (982500) PHYSIOLOGY-FACTORS-AFFECTING-PERFORMANCE-NUTRITION SC: 982500, 982 AB: Aiming at providing a brief review of the existing scientific literature concerning dietary creatine supplementation and its efficiency in improving physical performance of human beings, the paper discusses the following issues: a) the need and sources of creatine in humans; b) function of creatine in skeletal muscles; c) effect of dietary creatine supplementation on a skeletal muscle creatine content; d) effect of dietary creatine supplementation on muscle metabolism and physical performance capacity; e) dietary creatine supplementation and sports performance; f) side effects of creatine supplementation. It has been said in conclusion that though the stimulating effect of creatine on performance in untrained persons during a high-intensity intermittent exercise is known, current experimental data do not provide convincing proof on the positive effect of creatine ingestion on performance in a continuous, short, intense or a prolonged exercise and information on its effects on sport performance is scarce. No side effects of a short-term creatine feeding are known but increases of body mass have been reported FRSH: (982500)
7 of 21 Marked Record TI: The effect of oral creatine supplementation on the 1000-m performance of competitive rowers AU: Rossiter,-H.-B; Cannell,-E.-R; Jakeman,-P.-M JN: Journal-of-sports-sciences-(London); 14(2), Apr 1996, 175-179 Refs:10 IS: 0264-0414 PY: 1996 LA: English DT: Serial-Article LE: Advanced DE: rowing-; athlete-; man-; woman-; dietary-supplementation; creatine- SH: (452114) ROWING-NUTRITION; (931480) DRUGS-AND-DOPING-ERGOGENIC-AIDS-AMINO-ACID-SUPPLEMENTATION SC: 452114, 452; 931480, 931 AB: This study investigated the change in 1000-m simulated rowing performance in two matched groups of 19 competitive rowers following a 5-day period of supplementation with placebo (CON group) or creatine at a dose equivalent to 0.25 g creatine monohydrate per kilogram of body mass (BM) (EXP group). Creatine uptake was calculated from the difference between the amount fed and the amount recovered in urine during each 24-h period of supplementation. Total creatine uptake for the EXP group over the 5-day period of supplementation averaged 34.9 plus/minus 10.9 g (range 20.1 - 54.9 g), which equated to 3.54 plus/minus 0.93 mmol kg BM-1. The estimated creatine uptake into muscle was 38.1 plus/minus 10.0 (range 22.6 - 56.6) mmol kg dry weight-1 for these subjects. After supplementation with placebo, the CON group showed no change in 1000-m rowing performance (214.0 plus/minus 30.9 vs 214.1 plus/minus 31.5 s; P = 0.88). By contrast, 16 of the 19 subjects in the EXP group improved their performance times. The mean improvement in rowing performance for the EXP group was 2.3 s (211.0 plus/minus 21.5 vs 208.7 plus/minus 21.8 s; P is less than 0.001), an overall improvement of just over 1 percent (range - 0.4 to 3.4 percent). We conclude that in competitive rowers, a 5-day period of creatine supplementation was effective in raising whole-body creatine stores, the magnitude of which provided a positive, though statistically non-significant (r - 0.426, P = 0.088), relationship with 1000-m rowing performance FRSH: (452114)
8 of 21 Marked Record TI: Practical application of oral creatine supplementation in professional rugby league : a case study AU: Meir,-R JN: Strength-and-conditioning-coach-(Brisbane,-Aust.); 3(3), 1995, 6-10 Refs:15 PY: 1995 LA: English DT: Serial-Article LE: Intermediate DE: rugby-league; creatine-; case-study SH: (575114) RUGBY-LEAGUE-NUTRITION SC: 575114, 575 FRSH: (575114) JEU-A-TREIZE-NUTRITION SPSH: (575114) RUGBY-LEAGUE-NUTRICION CP: Australia (036) SF: International Contribution; AAIS AN: 390532 UD: 9604 </p> <p>9 of 21 Marked Record TI: Creatine supplementation and dynamic high-intensity intermittent exercise AU: Balsom,-P.-D; Ekblom,-B; Soderlund,-K; Sjodin,-B; Hultman,-E JN: Scandinavian-journal-of-medicine-&-science-in-sports-(Copenhagen); 3(3), Aug 1993, 143-149 Refs:22 IS: 0905-7188 PY: 1993 LA: English DT: Serial-Article LE: Advanced DE: creatine-; exercise-; man-; lactate- SH: (980382) PHYSIOLOGY-ENERGY-METABOLISM-PROTEINS-AMINO-ACIDS SC: 980382, 980 FRSH: (980382)
10 of 21 Marked Record TI: Creating a fuss over creatine AU: Helgerud,-J; Hoff,-J JN: Corpus,-psyche-et-societas-(Trondheim,-Norway); 2(1), 1995, 95-104 Refs:19 IS: 0805-7095 PY: 1995 LA: English DT: Serial-Article LE: Advanced DE: creatine-; sport- SH: (931480) DRUGS-AND-DOPING-ERGOGENIC-AIDS-AMINO-ACID-SUPPLEMENTATION SC: 931480, 931 AB: This review of creatine supplementation discusses possible adverse effects and describes the practical application of its use in sports training and competition. The presence of creatine phosphate in muscle enables the prompt synthesis of ATP and, during all out exercise, there is sufficient stored phosphate energy for about 6-8 seconds work. The importance of creatine for short term energy release in high intensity performance has been overlooked by researchers for close on seventy years. Nevertheless, amongst those studies that have been carried out, short term training has not been found to bring about changes in the levels of skeletal muscle creatine phosphate. In contrast, a few studies have reported increased creatine phosphate levels following on resistance training, but no clear evidence has been provided. The increasing popularity of creatine supplementation can be attributed to a number of sources: the discovery of an increased total ceatine content in skeletal muscle in man - its demonstrated contribution to performance enhancement in high intensity intermittent exercise like cycling and rowing - the absence of reported adverse effects other than an increase in body mass - the fact that creatine is not on the IOC doping list FRSH: (931480)
11 of 21 Marked Record TI: Oral creatine supplementation does not improve sprint performance in elite swimmers - abstract AU: Burke,-L.-M; Pyne,-D.-B; Telford,-R.-D CA: Sports Medicine Australia SO: In, Abstracts, Australian Conference of Science and Medicine in Sport, Hobart, 17-20 October 1995, Canberra, Sports Medicine Australia, 1995, 2 p CN: Australian Conference of Science and Medicine in Sport (1995 : Hobart, Aust.) PY: 1995 LA: English DT: Book-Analytic LE: Advanced DE: sprint-swimming; elite-athlete; creatine-; achievement-; testing- SH: (408114) SWIMMING-NUTRITION SC: 408114, 408 FRSH: (408114) NATATION-NUTRITION SPSH: (408114) NATACION-NUTRICION CP: Australia (036) SF: International Contribution; AAIS; SIRC CL: RC1201 32781 AN: 386375 UD: 9604 </p> <p>12 of 21 Marked Record TI: Effect of training and nutrition on the development of skeletal muscle AU: Henriksson,-J JN: Journal-of-sports-sciences-(London); 13(Special Is), Summer 1995, S25-S30 Refs:55 IS: 0264-0414 CN: International Scientific Consensus Conference on Foods, Nutrition and Sports Performance (1995 : Monaco) PY: 1995 NT: Special issue: Current issues in nutrition in athletics. Proceedings of an International Scientific Consensus Conference held 18-20 February 1995, Monaco. LA: English DT: Serial-Article LE: Advanced DE: exercise-; training-; review-; nutrition-; muscle-metabolism SH: (969001) NUTRITION; (983400) PHYSIOLOGY-MUSCLE-METABOLISM SC: 969001, 969; 983400, 983 AB: Recent data suggest that an increased muscle mitochondrial oxidative capacity is not a prerequisite for a marked metabolic effect of endurance training, but instead may represent an adaptive phenomenon to the new metabolic situation. The muscle content of the glucose transporter GLUT-4 increases after one or only a few exercise sessions. The ensuing enhancement of the insulin sensitivity allows faster replenishment of muscle glycogen stores following exercise bouts. There is evidence that the muscle content of GLUT-4 declines more slowly with inactivity than the muscle oxidative capacity. This may be a sign that, as in the chronically stimulated rabbit muscle, adaptive changes in human skeletal muscle follow a "first-in, last-out" sequence. There is evidence that muscle (and possibly also plasma) triacyclglycerol is more important as an energy source during exercise than was previously recognized. Endurance training increases the content of slow isoforms of myosin in the muscle, and information on changes in muscle shortening velocity and on the molecular regulation of muscle volume is emerging. Beta2-agonists are well documented to enhance muscle mass, whereas creatine supplementation appears to enhance performance during high-intensity exercise FRSH: (969001) NUTRITION; (983400)
13 of 21 Marked Record TI: Creatine supplementation in swimming: does it give you an edge? AU: Thompson,-K JN: Swimming-times-(Loughborough,-England); 52(5), June 1995, 25-26 IS: 0039-7423 PY: 1995 LA: English DT: Serial-Article LE: Basic DE: swimming-; ergogenic-aid; creatine- SH: (408060) SWIMMING-DRUGS-DOPING-AND-ERGOGENIC-AIDS; (931480) DRUGS-AND-DOPING-ERGOGENIC-AIDS-AMINO-ACID-SUPPLEMENTATION SC: 408060, 408; 931480, 931 FRSH: (408060)
14 of 21 Marked Record TI: Effect of oral creatine supplementation on power output and fatigue during bicycle ergometry AU: Cooke,-W.-H; Grandjean,-P.-W; Barnes,-W.-S JN: Journal-of-applied-physiology-(Bethesda,-Md.); 78(2), Feb 1995, 670-673 Refs:15 IS: 8750-7587 PY: 1995 LA: English DT: Serial-Article LE: Advanced DE: phosphocreatine-; exercise-; dietary-supplementation; cratine-; fatigue-; bicycle-ergometry; man-; young-adult; power- SH: (981600) PHYSIOLOGY-EXERCISE-TESTING; (981050) PHYSIOLOGY-EXERCISE-ACUTE-ADAPTATIONS SC: 981600, 981; 981050, 981 FRSH: (981600)
15 of 21 Marked Record TI: Creatine supplementation and exercise performance AU: Maughan,-R.-J JN: International-journal-of-sport-nutrition-(Champaign,-Ill.); 5(2), June 1995, 94-101 Refs:23 IS: 1050-1606 PY: 1995 LA: English DT: Serial-Article LE: Intermediate DE: creatine-; exercise-; achievement-; correlation-; review- SH: (931520) DRUGS-AND-DOPING-ERGOGENIC-AIDS-NUTRITION; (980382) PHYSIOLOGY-ENERGY-METABOLISM-PROTEINS-AMINO-ACIDS SC: 931520, 931; 980382, 980 AB: Creatine phosphate allows high rates of adenosine triphosphate resynthesis to occur in muscle and therefore plays a vital role in the performance of high-intensity exercise. Recent studies have shown that feed large amounts of creatine (typically 20 g per day for 5 days) increases muscle total creatine (and phosphocreatine) content. The extent of the increase that is normally observed in inversely related to the presupplementation level. Vegetarians, who have a very low dietary creatine intake, generally show the largest increases. Creatine supplementation has been shown to increase performance in situations where the availability of creatine phosphate is important; thus, performance is improved in very high-intensity exercise and especially where repeated sprints are performed with short recovery periods. Creatine supplementation is widely practiced by athletes in many sports and does not contravene current doping regulations. There are no reports of harmful side effects at the recommended dosage FRSH: (931520)
16 of 21 Marked Record TI: Effect of dietary creatine supplementation on maximal exercise performance AU: Birch,-R; Noble,-D; Greenhaff,-P.-L JN: Clinical-journal-of-sport-medicine-(New-York); 5(2), Apr 1995, 145 IS: 1050-642X PY: 1995 LA: English DT: Serial-Article LE: Advanced DE: dietary-supplementation; creatine-; exercise-; man-; young-adult; bicycle-ergometry; aerobic-capacity SH: (980382) PHYSIOLOGY-ENERGY-METABOLISM-PROTEINS-AMINO-ACIDS SC: 980382, 980 FRSH: (980382)
17 of 21 Marked Record TI: High intensity intermittent exercise: performance and metabolic responses with very high intensity short duration work periods AU: Balsom,-P.-D SO: Karolinska Institute, Stockholm, 1995, 1 v. in various pagings IB: 9162814907 PY: 1995 NT: Thesis - Karolinska Institute, Stockholm, Sweden, 1995. LA: English DT: Thesis; Monograph-Book LE: Advanced DE: adenine-nucleotide; creatine-; glycogen-; glycolysis-; lactate-; metabolism-; oxygen-consumption; achievement-; recovery- SH: (980001) PHYSIOLOGY-ENERGY-METABOLISM SC: 980001, 980 AB: High intensity intermittent exercise represents an activity pattern similar to that seen in many sports, e.g., football, tennis and hockey, where periods of intense exercise are interspersed with periods of either active or passive recovery. The aim of this thesis was to evaluate how the different energy systems are utilised during this type of exercise with very high intensity (greater than 200 percent VO2max), short duration work periods (less than or equal to 10s) and to investigate metabolic factors which may be limiting performance. Highly motivated, physically active males were used as subjects in all studies. This type of exercise imposed very high energy demands on both anaerobic and aerobic metabolism. Performance, defined as the ability to maintain a high target power output during consecutive work periods, was found to be markedly influenced by only small changes in the exercise duration and intensity, and the duration of intervening recovery periods. Performance, defined as the ability to maintain a high target power output during consecutive work periods, was found to be markedly influenced by only small changes in the exercise duration and intensity, and the duration of intervening recovery periods. Performance was impaired with low pre-exercise muscle glycogen concentration and when oxygen availability to the working muscles was reduced. On the other hand, following a regimen of creatine supplementation, which was shown to increase the total creatine concentration in m. vastus lateralis at rest, performance was enhanced. It is suggested that under conditions where the metabolic demands of the exercise causes a decline in power output after only a few work periods, substrate availability for anaerobic energy production may be a limiting factor for performance. However, the actual cause of fatigue was not elucidated. With a slightly lower, but still very high exercise intensity, where power output could be maintained for a more prolonged period of time, performance was limited by the availability of muscle glycogen, seemingly in much the same way as during continuous moderate intensity exercise FRSH: (980001)
18 of 21 Marked Record TI: Creatine supplementation AU: Nuttall,-F JN: Athletics-coach-(Birmingham,-England); 28(3), Autumn 1994, 12-13 IS: 0267-0267 PY: 1994 LA: English DT: Serial-Article LE: Basic DE: dietary-supplementation; creatine- SH: (931480) DRUGS-AND-DOPING-ERGOGENIC-AIDS-AMINO-ACID-SUPPLEMENTATION SC: 931480, 931 FRSH: (931480)
19 of 21 Marked Record TI: Creatine in humans with special reference to creatine supplementation AU: Balsom,-P.-D; Soderlund,-K; Ekblom,-B JN: Sports-medicine-(Auckland,-N.Z.); 18(4), Oct 1994, 268-280 Refs:78 IS: 0112-1642 PY: 1994 LA: English DT: Serial-Article LE: Intermediate DE: review-; creatine-; muscle-metabolism; nutrition-; adaptation-; exercise-; endurance-; amino-acid; dietary-supplementation SH: (983400) PHYSIOLOGY-MUSCLE-METABOLISM; (931480) DRUGS-AND-DOPING-ERGOGENIC-AIDS-AMINO-ACID-SUPPLEMENTATION SC: 983400, 983; 931480, 931 AB: Since the discovery of creatine in 1832, it has fascinated scientists with its central role in skeletal muscle metabolism. In humans, over 95 percent of the total creatine (Crtot) content is located in skeletal muscle, of which approximately a third is in its free (Crf) form. The remainder is present in a phosphorylated (Crphos) form. Crf and Crphos levels in skeletal muscle are subject to individual variations and are influenced by factors such as muscle fibre type, age and disease, but not apparently by training or gender. Daily turnover of creatine to creatinine for a 70kg male has been estimated to be around 2h. Part of this turnover can be replaced through exogenous sources of creatine in foods, especially meat and fish. The remainder is derived via endogenous synthesis from the precursors arginine, glycine and methionine. A century ago, studies with creatine feeding concluded that some of the ingested creatine was retained in the body. Subsequent studies have shown that both Crf and Crphos levels in skeletal muscle can be increased, and performance of high intensity intermittent exercise enhanced, following a period of creatine supplementation. However, neither endurance exercise performance nor maximal oxygen uptake appears to be enhanced. No adverse effects have been identified with short term creatine feeding. Creatine supplementation has been used in the treatment of diseases where creatine synthesis is inhibited FRSH: (983400)
20 of 21 Marked Record TI: The influence of dietary creatine supplementation on performance during repeated bouts of maximal isokinetic cycling in man AU: Birch,-R; Noble,-D; Greenhaff,-P.-L JN: European-journal-of-applied-physiology-and-occupational-physiology-(Berlin); 69(3), Sept 1994, 268-270 Refs:11 IS: 0301-5548 PY: 1994 LA: English DT: Serial-Article LE: Advanced DE: exercise-; creatine-; fatigue-; adenosine-triphosphate; blood-; lactate-; achievement-; adaptation-; isokinetic-; man-; cycling- SH: (796127) CYCLING-PHYSIOLOGY; (980350) PHYSIOLOGY-ENERGY-METABOLISM-LACTATE SC: 796127, 796; 980350, 980 AB: The effect of dietary creatine (Cr) suplementation on performance during 3, 30 s bouts maximal isokinetic cycling and on plasma ammonia and blood lactate accumulation during exercise was investigated. Placebo (P) ingestion had no effect on peak power output (PPO), mean power output (MPO) and total work output during each bout of exercise. Cr ingestion (4 x 5 g.day-1 for 5 days) significantly increased PPO in exercise bout 1 (p less than 0.05) and MPO and total work output in exercise bouts 1 (p less than 0.05), p less than 0.05, respectively) and 1 (p less than 0.05, p less than 0.05, respectively). Cr ingestion had no effect on any of the measures of performance during exercise bout 3. No difference was observed in peak plasma ammonia accumulation before (146 plus 30 mumol.l-1) and after (122 plus 17 mumol.l-1) P ingestion, however the corresponding concentration was lower following Cr ingestion (129 plus/minus 22 mumol.l-1) compared with before Cr ingestion (160 plus/minus 18 mumol.l-1, p less than 0.05), despite subjects performing more work. No difference in peak blood lactate accumulation was observed before and after P or Cr ingestion. The results demonstrate that Cr ingestion can increase whole body exercise performance during the initial two, but not a third, successive bout of maximal exercise lasting 30 s. The lower accumulation of plasma ammonia under these conditions suggest this response is achieved by an effect on muscle ATP turnover FRSH: (796127)
21 of 21 Marked Record TI: Influence of oral creatine supplementation on muscle torque during repeated bouts of maximal voluntary exercise in humans AU: Greenhaff,-P.-L; Casey,-A; Short,-A.-H; Harris,-R; Soderlund,-K; Hultman,-E JN: Clinical-science-(Essex,-Eng.); 84, 1993, 565-571 PY: 1993 LA: English DT: Serial-Article LE: Advanced DE: exercise-; muscle-; torque-; creatine-; muscle-metabolism; comparative-study; fatigue- SH: (980382) PHYSIOLOGY-ENERGY-METABOLISM-PROTEINS-AMINO-ACIDS; (983400) PHYSIOLOGY-MUSCLE-METABOLISM SC: 980382, 980; 983400, 983 FRSH: (980382) PHYSIOLOGIE-METABOLISME-DE-L'ENERGIE-PROTEINES-ACIDES-AMINES; (983400) PHYSIOLOGIE-MUSCLE-METABOLISME SPSH: (980382) FISIOLOGIA-METABOLISMO-DE-LA-ENERGIA-PROTEINAS-AMINO-ACIDOS; (983400) FISIOLOGIA-MUSCULO-METABOLISMO CP: United-Kingdom (826) AN: 354279 UD: 9501 </p> <p>MEDLINE EXPRESS (R) 1/96-1/97 1 of 14 Marked Record TI: The effect of oral creatine supplementation on the 1000-m performance of competitive rowers. AU: Rossiter-HB; Cannell-ER; Jakeman-PM AD: School of Sport and Exercise Sciences, University of Birmingham, Edgbaston, UK. SO: J-Sports-Sci. 1996 Apr; 14(2): 175-9 ISSN: 0264-0414 PY: 1996 LA: ENGLISH CP: ENGLAND AB: This study investigated the change in 1000-m simulated rowing performance in two matched groups of 19 competitive rowers following a 5-day period of supplementation with placebo (CON group) or creatine at a dose equivalent to 0.25 g creatine monohydrate per kilogram of body mass (BM) (EXP group). Creatine uptake was calculated from the difference between the amount fed and the amount recovered in urine during each 24-h period of supplementation. Total creatine uptake for the EXP group over the 5-day period of supplementation averaged 34.9 +/- 10.9 g (range 20.1-54.9 g), which equated to 3.54 +/- 0.93 mmol kg BM-1. The estimated creatine uptake into muscle was 38.1 +/- 10.0 (range 22.6-56.6) mmol kg dry weight-1 for these subjects. After supplementation with placebo, the CON group showed no change in 1000-m rowing performance (214.0 +/- 30.9 vs 214.1 +/- 31.5 s; P = 0.88). Of these subjects, 7 decreased and 10 increased their performance times (range - 3.1 to 2.7%). By contrast, 16 of the 19 subjects in the EXP group improved their performance times. The mean improvement in rowing performance for the EXP group was 2.3 s (211.0 +/- 21.5 vs 208.7 +/- 21.8 s; P < 0.001), an overall improvement of just over 1% (range - 0.4 to 3.4%). We conclude that in competitive rowers, a 5-day period of creatine supplementation was effective in raising whole-body creatine stores, the magnitude of which provided a positive, though statistically non-significant (r = 0.426, P = 0.088), relationship with 1000-m rowing performance. MESH: Adult-; Analysis-of-Variance; Creatine-pharmacology; Exercise- MESH: *Creatine-; *Food,-Fortified; *Sports-physiology; *Task-Performance-and-Analysis TG: Female; Human; Male PT: CLINICAL-TRIAL; CONTROLLED-CLINICAL-TRIAL; JOURNAL-ARTICLE RN: 57-00-1 NM: Creatine AN: 96301882 UD: 9611 </p> <p>MEDLINE EXPRESS (R) 1/96-1/97 2 of 14 Marked Record TI: Effect of creatine supplementation on intramuscular TCr, metabolism and performance during intermittent, supramaximal exercise in humans. AU: Febbraio-MA; Flanagan-TR; Snow-RJ; Zhao-S; Carey-MF AD: Department of Human Movement Science, Royal Melbourne Institute of Technology, Bundoora, Australia. SO: Acta-Physiol-Scand. 1995 Dec; 155(4): 387-95 ISSN: 0001-6772 PY: 1995 LA: ENGLISH CP: ENGLAND AB: This study examined the effect of (a) creatine supplementation on exercise metabolism and performance and (b) changes in intramuscular total creatine stores following a 5 day supplementation period and a 28 day wash-out period. Six men performed four exercise trials, each consisting of four 1 min cycling bouts, punctuated by 1 min of rest followed by a fifth bout to fatigue, all at a workload estimated to require 115 or 125% VO2,max. After three familiarization trials, one trial was conducted following a creatine monohydrate supplementation protocol (CREAT); the other after 28 d without creatine supplementation, in which the last 5 d involved placebo ingestion (CON). Intramuscular TCr was elevated (P < 0.05) in CREAT compared with the final familiarization trial (FAM 3) and CON. Concentrations of this metabolite in these latter trials were not different. In addition, a main effect (P < 0.05) for treatment was observed for PCr when the data from CREAT were compared with CON. In contrast, no differences were observed in the total adenine nucleotide pool (ATP+ADP+AMP), inosine 5'-monophosphate, ammonia, lactate or glycogen when comparing CREAT with CON. Despite the differences in TCr and PCr concentrations when comparing CREAT with other trials, no difference was observed in exercise duration in the fifth work bout. These data demonstrate that creatine supplementation results in an increase in TCr but this has no effect on performance during exercise of this nature, where the creatine kinase system is not the principal energy supplier. In addition 28 d without supplementation is a sufficient time to return intramuscular TCr stores to basal levels. MESH: Adenine-Nucleotides-metabolism; Adult-; Ammonia-blood; Hydrogen-Ion-Concentration; Lactates-blood; Muscle,-Skeletal-drug-effects; Oxygen-Consumption-drug-effects; Oxygen-Consumption-physiology MESH: *Creatine-metabolism; *Creatine-pharmacology; *Exercise-physiology; *Muscle,-Skeletal-metabolism TG: Human; Male; Support,-Non-U.S.-Gov't PT: JOURNAL-ARTICLE RN: 0; 0; 57-00-1; 7664-41-7 NM: Adenine-Nucleotides; Lactates; Creatine; Ammonia AN: 96318457 UD: 9611 </p> <p>MEDLINE EXPRESS (R) 1/96-1/97 3 of 14 Marked Record TI: Effects of oral creatine supplementation on multiple sprint cycle performance. AU: Barnett-C; Hinds-M; Jenkins-DG AD: Department of Human Movement Studies, University of Queensland. SO: Aust-J-Sci-Med-Sport. 1996 Mar; 28(1): 35-9 ISSN: 0813-6289 PY: 1996 LA: ENGLISH CP: AUSTRALIA AB: This study examined the influence of oral creatine monohydrate supplementation on repeated 10 s cycle ergometer sprint performance. Seventeen recreationally active males (mean +/- SD age, body mass, height, and peak oxygen uptake = 20.5 +/- 1.2 yr, 72.1 +/- 10.3 kg, 176.8 +/- 6.6 cm and 3.87 +/- 0.91 l.min-1, respectively) participated in the 16 day experiment. All subjects initially completed a VO2peak test and were then administered glucose (4 x 10 g per day) in a single blind fashion for four days, after which they completed the first series of multiple sprints (7 x 10 s). Following the sprints, subjects were matched on sprint performance and divided into two groups (n = 8, placebo (Pl); and n = 9, creatine (Cr)). For the following four days, diets were supplemented with either Cr (4 x 70 mg.kg-1 body mass per day mixed with 5 g glucose) or glucose (4 x 10 g per day); supplementation during this phase was double-blind. Subjects then repeated the multiple sprint and VO2peak tests. Measures of peak power output (PPO), mean power output (MPO), end-power output (EPO), and percent power decline were recorded during the sprints. Each 10 s sprint was separated by 30 s of passive recovery except for sprints five and six which were separated by five minutes. Venous blood was sampled at rest, immediately after sprint five, before sprint six, and following sprint seven for the analysis of plasma lactate and blood pH. Expired air was sampled for five minutes following sprint seven for the calculation of post-exercise VO2. Analysis of variance revealed that four days of Cr supplementation did not influence multiple sprint performance, plasma lactate, blood pH and excess post-sprint oxygen consumption. Furthermore, VO2peak was unchanged following Cr supplementation. The data suggest that either the four day period of Cr supplementation failed to significantly raise resting muscle [Cr], or that multiple sprint performance was not enhanced by increases in resting muscle [Cr]. MESH: Adult-; Food,-Fortified; Lactates-blood; Oxygen-Consumption MESH: *Bicycling-physiology; *Creatinine-pharmacology; *Exercise-physiology TG: Human; Male PT: JOURNAL-ARTICLE RN: 0; 50-21-5; 60-27-5 NM: Lactates; lactic-acid; Creatinine AN: 96301567 UD: 9611 </p> <p>MEDLINE EXPRESS (R) 1/96-1/97 4 of 14 Marked Record TI: Creatine supplementation in chronic heart failure increases skeletal muscle creatine phosphate and muscle performance. AU: Gordon-A; Hultman-E; Kaijser-L; Kristjansson-S; Rolf-CJ; Nyquist-O; Sylven-C AD: Department of Medicine, Karolinska Institute, Huddinge University Hospital, Sweden. SO: Cardiovasc-Res. 1995 Sep; 30(3): 413-8 ISSN: 0008-6363 PY: 1995 LA: ENGLISH CP: NETHERLANDS AB: BACKGROUND: Cardiac creatine levels are depressed in chronic heart failure. Oral supplementation of creatine to healthy volunteers has been shown to increase physical performance. AIM: To evaluate the effects of creatine supplementation on ejection fraction, symptom-limited physical endurance and skeletal muscle strength in patients with chronic heart failure. METHODS: With a double-blind, placebo-controlled design 17 patients (age 43-70 years, ejection fraction < 40) were supplemented with creatine 20 g daily for 10 days. Before and on the last day of supplementation ejection fraction was determined by radionuclide angiography as was symptom-limited 1-legged knee extensor and 2-legged exercise performance on the cycle ergometer. Muscle strength as unilateral concentric knee extensor performance (peak torque, Nm at 180 degrees/s) was also evaluated. Skeletal muscle biopsies were taken for the determination of energy-rich phosphagens. RESULTS: Ejection fraction at rest and at work did not change. Performance before creatine supplementation did not differ between placebo and creatine groups. While no change was seen in the placebo group compared to baseline, creatine supplementation increased skeletal muscle total creatine and creatine phosphate by 17 +/- 4% (P < 0.05) and 12 +/- 4% (P < 0.05), respectively. Increments were seen only in patients with < 140 mmol total creatine/kg d.w. (P < 0.05). One-legged performance (21%, P < 0.05), 2-legged performance (10%, P < 0.05), and peak torque, Nm (5%, P < 0.05) increased. Both peak torque and 1-legged performance increased linearly with increased skeletal muscle phosphocreatine (P < 0.05). The increments in 1-legged, 2-legged and peak torque were significant compared to the placebo group, (P < 0.05). CONCLUSIONS: One week of creatine supplementation to patients with chronic heart failure did not increase ejection fraction but increased skeletal muscle energy-rich phosphagens and performance as regards both strength and endurance. This new therapeutic approach merits further attention. MESH: Administration,-Oral; Adult-; Aged-; Cardiac-Output-drug-effects; Chronic-Disease; Creatine-pharmacology; Double-Blind-Method; Heart-Failure,-Congestive-physiopathology; Heart-Failure,-Congestive-radionuclide-imaging; Middle-Age; Muscle,-Skeletal-metabolism; Muscle,-Skeletal-physiopathology; Radionuclide-Angiography MESH: *Creatine-administration-and-dosage; *Heart-Failure,-Congestive-drug-therapy; *Muscle,-Skeletal-drug-effects; *Phosphocreatine-metabolism; *Physical-Endurance-drug-effects TG: Comparative-Study; Human; Male; Support,-Non-U.S.-Gov't PT: CLINICAL-TRIAL; JOURNAL-ARTICLE; RANDOMIZED-CONTROLLED-TRIAL RN: 57-00-1; 67-07-2 NM: Creatine; Phosphocreatine AN: 96091487 UD: 9602 </p> <p>MEDLINE EXPRESS (R) 1991-1995 5 of 14 Marked Record TI: Skeletal muscle metabolism during short duration high-intensity exercise: influence of creatine supplementation. AU: Balsom-PD; Soderlund-K; Sjodin-B; Ekblom-B AD: Karolinska Institute, Department of Physiology and Pharmacology, Physiology III, Stockholm, Sweden. SO: Acta-Physiol-Scand. 1995 Jul; 154(3): 303-10 ISSN: 0001-6772 PY: 1995 LA: ENGLISH CP: ENGLAND AB: Seven male subjects performed repeated bouts of high-intensity exercise, on a cycle ergometer, before and after 6 d of creatine supplementation (20 g Cr H2O day-1). The exercise protocol consisted of five 6-s exercise periods performed at a fixed exercise intensity, interspersed with 30-s recovery periods (Part I), followed (40 s later) by one 10 s exercise period (Part II) where the ability to maintain power output was evaluated. Muscle biopsies were taken from m. vastus lateralis at rest, and immediately after (i) the fifth 6 s exercise period in Part I and (ii) the 10 s exercise period in Part II. In addition, a series of counter movement (CMJ) and squat (SJ) jumps were performed before and after the administration period. As a result of the creatine supplementation, total muscle creatine [creatine (Cr) + phosphocreatine (PCr)] concentration at rest increased from (mean +/- SEM) 128.7 (4.3) to 151.5 (5.5) mmol kg-1 dry wt (P < 0.05). This was accompanied by a 1.1 (0.5) kg increase in body mass (P < 0.05). After the fifth exercise bout in Part I of the exercise protocol, PCr concentration was higher [69.7 (2.3) vs. 45.6 (7.5) mmol kg-1 dry wt, P < 0.05], and muscle lactate was lower [26.2 (5.5) vs. 44.3 (9.9) mmol kg-1 dry wt, P < 0.05] after vs. before supplementation. In Part II, after creatinine supplementation, subjects were better able to maintain power output during the 10-s exercise period (P < 0.05). There was no change in jump performance as a result of the creatine supplementation (P > 0.05).(ABSTRACT TRUNCATED AT 250 WORDS) MESH: Adenosine-Triphosphate-blood; Adenosine-Triphosphate-metabolism; Adult-; Body-Weight-physiology; Creatine-blood; Creatine-metabolism; Exercise-Test; Glycolysis-drug-effects; Hypoxanthines-blood; Lactates-blood; Lactates-metabolism; Muscle-Fatigue-physiology; Muscle,-Skeletal-drug-effects; Phosphocreatine-blood; Phosphocreatine-metabolism MESH: *Creatine-pharmacology; *Exercise-physiology; *Muscle,-Skeletal-metabolism TG: Human; Male; Support,-Non-U.S.-Gov't PT: CLINICAL-TRIAL; JOURNAL-ARTICLE RN: 0; 0; 50-21-5; 56-65-5; 57-00-1; 67-07-2; 68-94-0 NM: Hypoxanthines; Lactates; lactic-acid; Adenosine-Triphosphate; Creatine; Phosphocreatine; hypoxanthine AN: 96044912 UD: 9601 </p> <p>MEDLINE EXPRESS (R) 1991-1995 6 of 14 Marked Record TI: Creatine supplementation and exercise performance. AU: Maughan-RJ AD: Department of Environmental and Occupational Medicine, University Medical School, Foresterhill, Aberdeen, Scotland. SO: Int-J-Sport-Nutr. 1995 Jun; 5(2): 94-101 ISSN: 1050-1606 PY: 1995 LA: ENGLISH CP: UNITED-STATES AB: Creatine phosphate allows high rates of adenosine triphosphate resynthesis to occur in muscle and therefore plays a vital role in the performance of high-intensity exercise. Recent studies have shown that feeding large amounts of creatine (typically 20 g per day for 5 days) increases muscle total creatine (and phosphocreatine) content. The extent of the increase that is normally observed is inversely related to the presupplementation level. Vegetarians, who have a very low dietary creatine intake, generally show the largest increases. Creatine supplementation has been shown to increase performance in situations where the availability of creatine phosphate is important; thus, performance is improved in very high-intensity exercise and especially where repeated sprints are performed with short recovery periods. Creatine supplementation is widely practiced by athletes in many sports and does not contravene current doping regulations. There are no reports of harmful side effects at the recommended dosage. MESH: Adenosine-Triphosphate-metabolism; Creatine-administration-and-dosage; Creatine-metabolism; Food,-Fortified MESH: *Creatine-pharmacology; *Exercise-physiology TG: Human PT: JOURNAL-ARTICLE; REVIEW; REVIEW,-TUTORIAL RN: 56-65-5; 57-00-1 NM: Adenosine-Triphosphate; Creatine AN: </p> </body>
MEDLINE EXPRESS (R) 1/96-1/97 1 of 15 Marked Record TI: The effect of oral creatine supplementation on the 1000-m performance of competitive rowers. AU: Rossiter-HB; Cannell-ER; Jakeman-PM AD: School of Sport and Exercise Sciences, University of Birmingham, Edgbaston, UK. SO: J-Sports-Sci. 1996 Apr; 14(2): 175-9 ISSN: 0264-0414 PY: 1996 LA: ENGLISH CP: ENGLAND AB: This study investigated the change in 1000-m simulated rowing performance in two matched groups of 19 competitive rowers following a 5-day period of supplementation with placebo (CON group) or creatine at a dose equivalent to 0.25 g creatine monohydrate per kilogram of body mass (BM) (EXP group). Creatine uptake was calculated from the difference between the amount fed and the amount recovered in urine during each 24-h period of supplementation. Total creatine uptake for the EXP group over the 5-day period of supplementation averaged 34.9 +/- 10.9 g (range 20.1-54.9 g), which equated to 3.54 +/- 0.93 mmol kg BM-1. The estimated creatine uptake into muscle was 38.1 +/- 10.0 (range 22.6-56.6) mmol kg dry weight-1 for these subjects. After supplementation with placebo, the CON group showed no change in 1000-m rowing performance (214.0 +/- 30.9 vs 214.1 +/- 31.5 s; P = 0.88). Of these subjects, 7 decreased and 10 increased their performance times (range - 3.1 to 2.7%). By contrast, 16 of the 19 subjects in the EXP group improved their performance times. The mean improvement in rowing performance for the EXP group was 2.3 s (211.0 +/- 21.5 vs 208.7 +/- 21.8 s; P < 0.001), an overall improvement of just over 1% (range - 0.4 to 3.4%). We conclude that in competitive rowers, a 5-day period of creatine supplementation was effective in raising whole-body creatine stores, the magnitude of which provided a positive, though statistically non-significant (r = 0.426, P = 0.088), relationship with 1000-m rowing performance. MESH: Adult-; Analysis-of-Variance; Creatine-pharmacology; Exercise- MESH: *Creatine-; *Food,-Fortified; *Sports-physiology; *Task-Performance-and-Analysis TG: Female; Human; Male PT: CLINICAL-TRIAL; CONTROLLED-CLINICAL-TRIAL; JOURNAL-ARTICLE RN: 57-00-1 NM: Creatine AN: 96301882 UD: 9611
MEDLINE EXPRESS (R) 1/96-1/97 2 of 15 Marked Record TI: Effect of creatine supplementation on intramuscular TCr, metabolism and performance during intermittent, supramaximal exercise in humans. AU: Febbraio-MA; Flanagan-TR; Snow-RJ; Zhao-S; Carey-MF AD: Department of Human Movement Science, Royal Melbourne Institute of Technology, Bundoora, Australia. SO: Acta-Physiol-Scand. 1995 Dec; 155(4): 387-95 ISSN: 0001-6772 PY: 1995 LA: ENGLISH CP: ENGLAND AB: This study examined the effect of (a) creatine supplementation on exercise metabolism and performance and (b) changes in intramuscular total creatine stores following a 5 day supplementation period and a 28 day wash-out period. Six men performed four exercise trials, each consisting of four 1 min cycling bouts, punctuated by 1 min of rest followed by a fifth bout to fatigue, all at a workload estimated to require 115 or 125% VO2,max. After three familiarization trials, one trial was conducted following a creatine monohydrate supplementation protocol (CREAT); the other after 28 d without creatine supplementation, in which the last 5 d involved placebo ingestion (CON). Intramuscular TCr was elevated (P < 0.05) in CREAT compared with the final familiarization trial (FAM 3) and CON. Concentrations of this metabolite in these latter trials were not different. In addition, a main effect (P < 0.05) for treatment was observed for PCr when the data from CREAT were compared with CON. In contrast, no differences were observed in the total adenine nucleotide pool (ATP+ADP+AMP), inosine 5'-monophosphate, ammonia, lactate or glycogen when comparing CREAT with CON. Despite the differences in TCr and PCr concentrations when comparing CREAT with other trials, no difference was observed in exercise duration in the fifth work bout. These data demonstrate that creatine supplementation results in an increase in TCr but this has no effect on performance during exercise of this nature, where the creatine kinase system is not the principal energy supplier. In addition 28 d without supplementation is a sufficient time to return intramuscular TCr stores to basal levels. MESH: Adenine-Nucleotides-metabolism; Adult-; Ammonia-blood; Hydrogen-Ion-Concentration; Lactates-blood; Muscle,-Skeletal-drug-effects; Oxygen-Consumption-drug-effects; Oxygen-Consumption-physiology MESH: *Creatine-metabolism; *Creatine-pharmacology; *Exercise-physiology; *Muscle,-Skeletal-metabolism TG: Human; Male; Support,-Non-U.S.-Gov't PT: JOURNAL-ARTICLE RN: 0; 0; 57-00-1; 7664-41-7 NM: Adenine-Nucleotides; Lactates; Creatine; Ammonia AN: 96318457 UD: 9611
MEDLINE EXPRESS (R) 1/96-1/97 3 of 15 Marked Record TI: Effects of oral creatine supplementation on multiple sprint cycle performance. AU: Barnett-C; Hinds-M; Jenkins-DG AD: Department of Human Movement Studies, University of Queensland. SO: Aust-J-Sci-Med-Sport. 1996 Mar; 28(1): 35-9 ISSN: 0813-6289 PY: 1996 LA: ENGLISH CP: AUSTRALIA AB: This study examined the influence of oral creatine monohydrate supplementation on repeated 10 s cycle ergometer sprint performance. Seventeen recreationally active males (mean +/- SD age, body mass, height, and peak oxygen uptake = 20.5 +/- 1.2 yr, 72.1 +/- 10.3 kg, 176.8 +/- 6.6 cm and 3.87 +/- 0.91 l.min-1, respectively) participated in the 16 day experiment. All subjects initially completed a VO2peak test and were then administered glucose (4 x 10 g per day) in a single blind fashion for four days, after which they completed the first series of multiple sprints (7 x 10 s). Following the sprints, subjects were matched on sprint performance and divided into two groups (n = 8, placebo (Pl); and n = 9, creatine (Cr)). For the following four days, diets were supplemented with either Cr (4 x 70 mg.kg-1 body mass per day mixed with 5 g glucose) or glucose (4 x 10 g per day); supplementation during this phase was double-blind. Subjects then repeated the multiple sprint and VO2peak tests. Measures of peak power output (PPO), mean power output (MPO), end-power output (EPO), and percent power decline were recorded during the sprints. Each 10 s sprint was separated by 30 s of passive recovery except for sprints five and six which were separated by five minutes. Venous blood was sampled at rest, immediately after sprint five, before sprint six, and following sprint seven for the analysis of plasma lactate and blood pH. Expired air was sampled for five minutes following sprint seven for the calculation of post-exercise VO2. Analysis of variance revealed that four days of Cr supplementation did not influence multiple sprint performance, plasma lactate, blood pH and excess post-sprint oxygen consumption. Furthermore, VO2peak was unchanged following Cr supplementation. The data suggest that either the four day period of Cr supplementation failed to significantly raise resting muscle [Cr], or that multiple sprint performance was not enhanced by increases in resting muscle [Cr]. MESH: Adult-; Food,-Fortified; Lactates-blood; Oxygen-Consumption MESH: *Bicycling-physiology; *Creatinine-pharmacology; *Exercise-physiology TG: Human; Male PT: JOURNAL-ARTICLE RN: 0; 50-21-5; 60-27-5 NM: Lactates; lactic-acid; Creatinine AN: 96301567 UD: 9611
MEDLINE EXPRESS (R) 1/96-1/97 4 of 15 Marked Record TI: Creatine supplementation in chronic heart failure increases skeletal muscle creatine phosphate and muscle performance. AU: Gordon-A; Hultman-E; Kaijser-L; Kristjansson-S; Rolf-CJ; Nyquist-O; Sylven-C AD: Department of Medicine, Karolinska Institute, Huddinge University Hospital, Sweden. SO: Cardiovasc-Res. 1995 Sep; 30(3): 413-8 ISSN: 0008-6363 PY: 1995 LA: ENGLISH CP: NETHERLANDS AB: BACKGROUND: Cardiac creatine levels are depressed in chronic heart failure. Oral supplementation of creatine to healthy volunteers has been shown to increase physical performance. AIM: To evaluate the effects of creatine supplementation on ejection fraction, symptom-limited physical endurance and skeletal muscle strength in patients with chronic heart failure. METHODS: With a double-blind, placebo-controlled design 17 patients (age 43-70 years, ejection fraction < 40) were supplemented with creatine 20 g daily for 10 days. Before and on the last day of supplementation ejection fraction was determined by radionuclide angiography as was symptom-limited 1-legged knee extensor and 2-legged exercise performance on the cycle ergometer. Muscle strength as unilateral concentric knee extensor performance (peak torque, Nm at 180 degrees/s) was also evaluated. Skeletal muscle biopsies were taken for the determination of energy-rich phosphagens. RESULTS: Ejection fraction at rest and at work did not change. Performance before creatine supplementation did not differ between placebo and creatine groups. While no change was seen in the placebo group compared to baseline, creatine supplementation increased skeletal muscle total creatine and creatine phosphate by 17 +/- 4% (P < 0.05) and 12 +/- 4% (P < 0.05), respectively. Increments were seen only in patients with < 140 mmol total creatine/kg d.w. (P < 0.05). One-legged performance (21%, P < 0.05), 2-legged performance (10%, P < 0.05), and peak torque, Nm (5%, P < 0.05) increased. Both peak torque and 1-legged performance increased linearly with increased skeletal muscle phosphocreatine (P < 0.05). The increments in 1-legged, 2-legged and peak torque were significant compared to the placebo group, (P < 0.05). CONCLUSIONS: One week of creatine supplementation to patients with chronic heart failure did not increase ejection fraction but increased skeletal muscle energy-rich phosphagens and performance as regards both strength and endurance. This new therapeutic approach merits further attention. MESH: Administration,-Oral; Adult-; Aged-; Cardiac-Output-drug-effects; Chronic-Disease; Creatine-pharmacology; Double-Blind-Method; Heart-Failure,-Congestive-physiopathology; Heart-Failure,-Congestive-radionuclide-imaging; Middle-Age; Muscle,-Skeletal-metabolism; Muscle,-Skeletal-physiopathology; Radionuclide-Angiography MESH: *Creatine-administration-and-dosage; *Heart-Failure,-Congestive-drug-therapy; *Muscle,-Skeletal-drug-effects; *Phosphocreatine-metabolism; *Physical-Endurance-drug-effects TG: Comparative-Study; Human; Male; Support,-Non-U.S.-Gov't PT: CLINICAL-TRIAL; JOURNAL-ARTICLE; RANDOMIZED-CONTROLLED-TRIAL RN: 57-00-1; 67-07-2 NM: Creatine; Phosphocreatine AN: 96091487 UD: 9602
MEDLINE EXPRESS (R) 1991-1995 5 of 15 Marked Record TI: Skeletal muscle metabolism during short duration high-intensity exercise: influence of creatine supplementation. AU: Balsom-PD; Soderlund-K; Sjodin-B; Ekblom-B AD: Karolinska Institute, Department of Physiology and Pharmacology, Physiology III, Stockholm, Sweden. SO: Acta-Physiol-Scand. 1995 Jul; 154(3): 303-10 ISSN: 0001-6772 PY: 1995 LA: ENGLISH CP: ENGLAND AB: Seven male subjects performed repeated bouts of high-intensity exercise, on a cycle ergometer, before and after 6 d of creatine supplementation (20 g Cr H2O day-1). The exercise protocol consisted of five 6-s exercise periods performed at a fixed exercise intensity, interspersed with 30-s recovery periods (Part I), followed (40 s later) by one 10 s exercise period (Part II) where the ability to maintain power output was evaluated. Muscle biopsies were taken from m. vastus lateralis at rest, and immediately after (i) the fifth 6 s exercise period in Part I and (ii) the 10 s exercise period in Part II. In addition, a series of counter movement (CMJ) and squat (SJ) jumps were performed before and after the administration period. As a result of the creatine supplementation, total muscle creatine [creatine (Cr) + phosphocreatine (PCr)] concentration at rest increased from (mean +/- SEM) 128.7 (4.3) to 151.5 (5.5) mmol kg-1 dry wt (P < 0.05). This was accompanied by a 1.1 (0.5) kg increase in body mass (P < 0.05). After the fifth exercise bout in Part I of the exercise protocol, PCr concentration was higher [69.7 (2.3) vs. 45.6 (7.5) mmol kg-1 dry wt, P < 0.05], and muscle lactate was lower [26.2 (5.5) vs. 44.3 (9.9) mmol kg-1 dry wt, P < 0.05] after vs. before supplementation. In Part II, after creatinine supplementation, subjects were better able to maintain power output during the 10-s exercise period (P < 0.05). There was no change in jump performance as a result of the creatine supplementation (P > 0.05).(ABSTRACT TRUNCATED AT 250 WORDS) MESH: Adenosine-Triphosphate-blood; Adenosine-Triphosphate-metabolism; Adult-; Body-Weight-physiology; Creatine-blood; Creatine-metabolism; Exercise-Test; Glycolysis-drug-effects; Hypoxanthines-blood; Lactates-blood; Lactates-metabolism; Muscle-Fatigue-physiology; Muscle,-Skeletal-drug-effects; Phosphocreatine-blood; Phosphocreatine-metabolism MESH: *Creatine-pharmacology; *Exercise-physiology; *Muscle,-Skeletal-metabolism TG: Human; Male; Support,-Non-U.S.-Gov't PT: CLINICAL-TRIAL; JOURNAL-ARTICLE RN: 0; 0; 50-21-5; 56-65-5; 57-00-1; 67-07-2; 68-94-0 NM: Hypoxanthines; Lactates; lactic-acid; Adenosine-Triphosphate; Creatine; Phosphocreatine; hypoxanthine AN: 96044912 UD: 9601
MEDLINE EXPRESS (R) 1991-1995 6 of 15 Marked Record TI: Creatine supplementation and exercise performance. AU: Maughan-RJ AD: Department of Environmental and Occupational Medicine, University Medical School, Foresterhill, Aberdeen, Scotland. SO: Int-J-Sport-Nutr. 1995 Jun; 5(2): 94-101 ISSN: 1050-1606 PY: 1995 LA: ENGLISH CP: UNITED-STATES AB: Creatine phosphate allows high rates of adenosine triphosphate resynthesis to occur in muscle and therefore plays a vital role in the performance of high-intensity exercise. Recent studies have shown that feeding large amounts of creatine (typically 20 g per day for 5 days) increases muscle total creatine (and phosphocreatine) content. The extent of the increase that is normally observed is inversely related to the presupplementation level. Vegetarians, who have a very low dietary creatine intake, generally show the largest increases. Creatine supplementation has been shown to increase performance in situations where the availability of creatine phosphate is important; thus, performance is improved in very high-intensity exercise and especially where repeated sprints are performed with short recovery periods. Creatine supplementation is widely practiced by athletes in many sports and does not contravene current doping regulations. There are no reports of harmful side effects at the recommended dosage. MESH: Adenosine-Triphosphate-metabolism; Creatine-administration-and-dosage; Creatine-metabolism; Food,-Fortified MESH: *Creatine-pharmacology; *Exercise-physiology TG: Human PT: JOURNAL-ARTICLE; REVIEW; REVIEW,-TUTORIAL RN: 56-65-5; 57-00-1 NM: Adenosine-Triphosphate; Creatine AN: 95400285 UD: 9512
MEDLINE EXPRESS (R) 1991-1995 7 of 15 Marked Record TI: Effect of oral creatine supplementation on power output and fatigue during bicycle ergometry. AU: Cooke-WH; Grandjean-PW; Barnes-WS AD: Department of Health and Kinesiology, Texas A&M University, College Station 77843, USA. SO: J-Appl-Physiol. 1995 Feb; 78(2): 670-3 ISSN: 8750-7587 PY: 1995 LA: ENGLISH CP: UNITED-STATES AB: Our purpose was to determine the effect of oral creatine supplementation on exercise performance during high-intensity short-duration bicycle sprinting. Power output was recorded for 12 healthy untrained males (age 24.08 +/- 0.53 yr, weight 81.22 +/- 1.32 kg) before and after 5 days of creatine (n = 6) or placebo (n = 6) supplementation. A double-blind research design was employed. Subjects performed maximal sprints against a constant load (111.8 N) for 15 s. Each one-half pedal revolution was magnetically counted, and subsequent measurements of peak power, time to peak power, total work, and the fatigue index were digitized and stored on disk. Mean values for peak power, time to peak power, total work, and fatigue index were 958.01 +/- 40.66 W, 4.09 +/- 0.82 s, 11.28 +/- 0.46 kJ, and 32.1 +/- 1.58% decline from peak power, respectively. No significant differences were observed within or between groups before or after supplementation for any of the mechanical parameters measured (P > 0.05). These findings suggest that oral creatine supplementation does not positively affect power output or fatigue during continuous high-intensity bicycle exercise in untrained men. MESH: Adult-; Double-Blind-Method; Exercise-Test MESH: *Creatine-pharmacology; *Exertion-drug-effects; *Muscle-Fatigue-drug-effects TG: Human; Male PT: CLINICAL-TRIAL; JOURNAL-ARTICLE; RANDOMIZED-CONTROLLED-TRIAL RN: 57-00-1 NM: Creatine AN: 95279305 UD: 9509
MEDLINE EXPRESS (R) 1991-1995 8 of 15 Marked Record TI: Effect of oral creatine supplementation on respiratory gas exchange and blood lactate accumulation during steady-state incremental treadmill exercise and recovery in man. AU: Stroud-MA; Holliman-D; Bell-D; Green-AL; Macdonald-IA; Greenhaff-PL AD: Centre for Human Sciences, Defence Research Agency, Farnborough, Hants, U.K. SO: Clin-Sci-Colch. 1994 Dec; 87(6): 707-10 ISSN: 0143-5221 PY: 1994 LA: ENGLISH CP: ENGLAND AB: 1. Oral creatine supplementation has been shown to increase muscle creatine and phosphocreatine concentrations with consequent benefits on performance during short-term maximal exercise. However, recently there have been anecdotal reports that creatine supplementation can also influence the pattern of substrate utilization and improve performance during more prolonged, submaximal exercise, which, based on recent experimental evidence, may have some scientific justification. 2. Eight men performed a continuous incremental exercise test running at 10 km/h on a motorized treadmill at predetermined workloads from 50% to 90% of maximal oxygen uptake, before and after 5 days of creatine supplementation (4 x 5 g daily). Exercise was performed for 6 min at each workload to achieve a steady state, and respiratory gas exchange and blood lactate concentrations were measured during the last 30 s at each workload. Measurements were also made at 5-min intervals for the first 15 min of recovery. 3. The results showed no measurable effect of creatine supplementation on respiratory gas exchange and blood lactate concentrations during either incremental submaximal exercise or recovery. This suggests that creatine supplementation does not influence substrate utilization during and after this type of exercise. MESH: Adult-; Exercise-Test; Oxygen-Consumption-drug-effects MESH: *Creatine-administration-and-dosage; *Lactates-blood; *Pulmonary-Gas-Exchange-drug-effects TG: Human; Male PT: JOURNAL-ARTICLE RN: 0; 57-00-1 NM: Lactates; Creatine AN: 95179935 UD: 9506
MEDLINE EXPRESS (R) 1991-1995 9 of 15 Marked Record TI: Creatine in humans with special reference to creatine supplementation. AU: Balsom-PD; Soderlund-K; Ekblom-B AD: Karolinska Institute, Department of Physiology and Pharmacology, Physiology III, Stockholm, Sweden. SO: Sports-Med. 1994 Oct; 18(4): 268-80 ISSN: 0112-1642 PY: 1994 LA: ENGLISH CP: NEW-ZEALAND AB: Since the discovery of creatine in 1832, it has fascinated scientists with its central role in skeletal muscle metabolism. In humans, over 95% of the total creatine (Crtot) content is located in skeletal muscle, of which approximately a third is in its free (Crf) form. The remainder is present in a phosphorylated (Crphos) form. Crf and Crphos levels in skeletal muscle are subject to individual variations and are influenced by factors such as muscle fibre type, age and disease, but not apparently by training or gender. Daily turnover of creatine to creatinine for a 70kg male has been estimated to be around 2g. Part of this turnover can be replaced through exogenous sources of creatine in foods, especially meat and fish. The remainder is derived via endogenous synthesis from the precursors arginine, glycine and methionine. A century ago, studies with creatine feeding concluded that some of the ingested creatine was retained in the body. Subsequent studies have shown that both Crf and Crphos levels in skeletal muscle can be increased, and performance of high intensity intermittent exercise enhanced, following a period of creatine supplementation. However, neither endurance exercise performance nor maximal oxygen uptake appears to be enhanced. No adverse effects have been identified with short term creatine feeding. Creatine supplementation has been used in the treatment of diseases where creatine synthesis is inhibited. MESH: Adolescence-; Adult-; Aged-; Creatine-metabolism; Creatinine-metabolism; Diet-; Exercise-physiology; Middle-Age; Muscle,-Skeletal-metabolism; Oxygen-Consumption-physiology; Phosphocreatine-metabolism; Physical-Endurance-physiology MESH: *Creatine-administration-and-dosage; *Creatine-physiology TG: Female; Human; Male; Support,-Non-U.S.-Gov't PT: JOURNAL-ARTICLE; REVIEW; REVIEW,-TUTORIAL RN: 57-00-1; 60-27-5; 67-07-2 NM: Creatine; Creatinine; Phosphocreatine AN: 95116784 UD: 9504
MEDLINE EXPRESS (R) 1991-1995 10 of 15 Marked Record TI: The influence of dietary creatine supplementation on performance during repeated bouts of maximal isokinetic cycling in man. AU: Birch-R; Noble-D; Greenhaff-PL AD: Department of Physiology and Pharmacology, University of Nottingham Medical School, Queen's Medical Centre, UK. SO: Eur-J-Appl-Physiol. 1994; 69(3): 268-76 ISSN: 0301-5548 PY: 1994 LA: ENGLISH CP: GERMANY AB: The effect of dietary creatine (Cr) supplementation on performance during 3, 30 s bouts maximal isokinetic cycling and on plasma ammonia and blood lactate accumulation during exercise was investigated. Placebo (P) ingestion had no effect on peak power output (PPO), mean power output (MPO) and total work output during each bout of exercise. Cr ingestion (4 x 5 g.day-1 for 5 days) significantly increased PPO in exercise bout 1 (p < 0.05) and MPO and total work output in exercise bouts 1 (p < 0.05, p < 0.05, respectively) and 2 (p < 0.05, p < 0.05, respectively). Cr ingestion had no effect on any of the measures of performance during exercise bout 3. No difference was observed in peak plasma ammonia accumulation before (146 + 30 mumol.l-1) and after (122 +/- 17 mumol.l-1) P ingestion, however the corresponding concentration was lower following Cr ingestion (129 +/- 22 mumol.l-1) compared with before Cr ingestion (160 +/- 18 mumol.l-1, p < 0.05), despite subjects performing more work. No difference in peak blood lactate accumulation was observed before and after P or Cr ingestion. The results demonstrate that Cr ingestion can increase whole body exercise performance during the initial two, but not a third, successive bout of maximal exercise lasting 30 s. The lower accumulation of plasma ammonia under these conditions suggests this response is achieved by an effect on muscle ATP turnover. MESH: Adenosine-Triphosphate-metabolism; Adult-; Ammonia-blood; Exercise-Test; Lactates-blood; Muscle,-Skeletal-metabolism; Phosphocreatine-metabolism MESH: *Creatine-administration-and-dosage; *Exercise-physiology; *Food,-Fortified TG: Human; Male PT: CLINICAL-TRIAL; JOURNAL-ARTICLE; RANDOMIZED-CONTROLLED-TRIAL RN: 0; 50-21-5; 56-65-5; 57-00-1; 67-07-2; 7664-41-7 NM: Lactates; lactic-acid; Adenosine-Triphosphate; Creatine; Phosphocreatine; Ammonia AN: 95094780 UD: 9503
MEDLINE EXPRESS (R) 1991-1995 11 of 15 Marked Record TI: Responses of contractile properties in rat soleus to high-energy phosphates and/or unloading. AU: Wakatsuki-T; Ohira-Y; Yasui-W; Nakamura-K; Asakura-T; Ohno-H; Yamamoto-M AD: Department of Physiology and Biomechanics, National Institute of Fitness and Sports, Kanoya, Japan. SO: Jpn-J-Physiol. 1994; 44(2): 193-204 ISSN: 0021-521X PY: 1994 LA: ENGLISH CP: JAPAN AB: Responses of contractile properties of soleus to unloading and/or changes in high-energy phosphate contents were studied in rats. Reduction of high-energy phosphates, especially phosphocreatine, in ankle extensors was induced by feeding beta-guanidinopropionic acid (beta-GPA). The major finding in the study was that the fatigability and speed-related contractile properties responded to unloading and creatine supplementation in a similar manner. The high-energy phosphate contents tended to be elevated after 10-d supplementation of creatine and hindlimb suspension. The shift toward slow-type, mainly due to an increased one-half relaxation time, was seen in rats fed beta-GPA. Such a shift was reversed by feeding creatine or by hindlimb suspension; however, the suspension-induced shift of contractile properties toward fast-type was not prevented completely by beta-GPA feeding. Although the muscle fatigue resistance did not change by beta-GPA feeding alone, the decrease in fatigue resistance following suspension and creatine supply was less in the beta-GPA group. It is suggested that the levels of high-energy phosphates and tension production play important roles in the regulation of contractile properties of the soleus muscle. MESH: Electric-Stimulation; Rats-; Rats,-Wistar; Weightlessness- MESH: *Energy-Metabolism; *Muscle-Contraction-drug-effects; *Muscles-drug-effects; *Phosphates-pharmacology TG: Animal; Male; Support,-Non-U.S.-Gov't PT: JOURNAL-ARTICLE RN: 0 NM: Phosphates AN: 95056701 UD: 9502
MEDLINE EXPRESS (R) 1991-1995 12 of 15 Marked Record TI: Effect of oral creatine supplementation on skeletal muscle phosphocreatine resynthesis. AU: Greenhaff-PL; Bodin-K; Soderlund-K; Hultman-E AD: Queens Medical Center, Department of Physiology and Pharmacology, University Medical School, Nottingham, United Kingdom. SO: Am-J-Physiol. 1994 May; 266(5 Pt 1): E725-30 ISSN: 0002-9513 PY: 1994 LA: ENGLISH CP: UNITED-STATES AB: Biopsy samples were obtained from the vastus lateralis muscle of eight subjects after 0, 20, 60, and 120 s of recovery from intense electrically evoked isometric contraction. Later (10 days), the same procedures were performed using the other leg, but subjects ingested 20 g creatine (Cr)/day for the preceding 5 days. Muscle ATP, phosphocreatine (PCr), free Cr, and lactate concentrations were measured, and total Cr was calculated as the sum of PCr and free Cr concentrations. In five of the eight subjects, Cr ingestion substantially increased muscle total Cr concentration (mean 29 +/- 3 mmol/kg dry matter, 25 +/- 3%; range 19-35 mmol/kg dry matter, 15-32%) and PCr resynthesis during recovery (mean 19 +/- 4 mmol/kg dry matter, 35 +/- 6%; range 11-28 mmol/kg dry matter, 23-53%). In the remaining three subjects, Cr ingestion had little effect on muscle total Cr concentration, producing increases of 8-9 mmol/kg dry matter (5-7%), and did not increase PCr resynthesis. The data suggest that a dietary-induced increase in muscle total Cr concentration can increase PCr resynthesis during the 2nd min of recovery from intense contraction. MESH: Administration,-Oral; Adult-; Biopsy-; Body-Weight; Creatine-administration-and-dosage; Lactates-metabolism; Muscles-cytology; Phosphocreatine-biosynthesis; Reference-Values; Weight-Gain MESH: *Creatine-metabolism; *Muscles-metabolism; *Phosphocreatine-metabolism TG: Human; Male PT: JOURNAL-ARTICLE RN: 0; 57-00-1; 67-07-2 NM: Lactates; Creatine; Phosphocreatine AN: 94262765 UD: 9409
MEDLINE EXPRESS (R) 1991-1995 13 of 15 Marked Record TI: Creatine supplementation per se does not enhance endurance exercise performance. AU: Balsom-PD; Harridge-SD; Soderlund-K; Sjodin-B; Ekblom-B AD: Karolinska Institute, Department of Physiology and Pharmacology, Physiology III, Stockholm, Sweden. SO: Acta-Physiol-Scand. 1993 Dec; 149(4): 521-3 ISSN: 0001-6772 PY: 1993 LA: ENGLISH CP: ENGLAND MESH: Adult-; Body-Weight; Double-Blind-Method; Exercise-Test; Oxygen-metabolism; Time-Factors MESH: *Creatine-administration-and-dosage; *Physical-Endurance-physiology TG: Human; Male; Support,-Non-U.S.-Gov't PT: CLINICAL-TRIAL; JOURNAL-ARTICLE; RANDOMIZED-CONTROLLED-TRIAL RN: 57-00-1; 7782-44-7 NM: Creatine; Oxygen AN: 94175016 UD: 9406
MEDLINE EXPRESS (R) 1991-1995 14 of 15 Marked Record TI: Influence of oral creatine supplementation of muscle torque during repeated bouts of maximal voluntary exercise in man. AU: Greenhaff-PL; Casey-A; Short-AH; Harris-R; Soderlund-K; Hultman-E AD: Department of Physiology and Pharmacology, Queens Medical Centre, University of Nottingham, U.K. SO: Clin-Sci-Colch. 1993 May; 84(5): 565-71 ISSN: 0143-5221 PY: 1993 LA: ENGLISH CP: ENGLAND AB: 1. The present experiment was undertaken to investigate the influence of oral creatine supplementation, shown previously to increase the total creatine content of human skeletal muscle (Harris RC, Soderlund K, Hultman E. Clin Sci 1992; 83: 367-74), on skeletal muscle isokinetic torque and the accumulation of plasma ammonia and blood lactate during five bouts of maximal exercise. 2. Twelve subjects undertook five bouts of 30 maximal voluntary isokinetic contractions, interspersed with 1 min recovery periods, before and after 5 days of placebo (4 x 6 g of glucose/day, n = 6) or creatine (4 x 5 g of creatine plus 1 g of glucose/day, n = 6) oral supplementation. Muscle torque production and plasma ammonia and blood lactate accumulation were measured during and after exercise on each treatment. 3. No difference was seen when comparing muscle peak torque production during exercise before and after placebo ingestion. After creatine ingestion, muscle peak torque production was greater in all subjects during the final 10 contractions of exercise bout 1 (P < 0.05), throughout the whole of exercise bouts 2 (P < 0.01), 3 (P < 0.05) and 4 (P = 0.057) and during contractions 11-20 of the final exercise bout (P < 0.05), when compared with the corresponding measurements made before creatine ingestion. Plasma ammonia accumulation was lower during and after exercise after creatine ingestion. No differences were found when comparing blood lactate levels.(ABSTRACT TRUNCATED AT 250 WORDS) MESH: Administration,-Oral; Adult-; Ammonia-blood; Double-Blind-Method; Drug-Administration-Schedule; Muscle-Contraction-drug-effects; Muscles-metabolism; Phosphocreatine-metabolism MESH: *Creatine-administration-and-dosage; *Muscle-Contraction-physiology TG: Comparative-Study; Female; Human; Male; Support,-Non-U.S.-Gov't PT: CLINICAL-TRIAL; CONTROLLED-CLINICAL-TRIAL; JOURNAL-ARTICLE RN: 57-00-1; 67-07-2; 7664-41-7 NM: Creatine; Phosphocreatine; Ammonia AN: 93278981 UD: 9309
MEDLINE EXPRESS (R) 1991-1995 15 of 15 Marked Record TI: Elevation of creatine in resting and exercised muscle of normal subjects by creatine supplementation. AU: Harris-RC; Soderlund-K; Hultman-E AD: Department of Clinical Chemistry II, Karolinska Institute, Huddinge University Hospital, Sweden. SO: Clin-Sci-Colch. 1992 Sep; 83(3): 367-74 ISSN: 0143-5221 PY: 1992 LA: ENGLISH CP: ENGLAND AB: 1. The present study was undertaken to test whether creatine given as a supplement to normal subjects was absorbed, and if continued resulted in an increase in the total creatine pool in muscle. An additional effect of exercise upon uptake into muscle was also investigated. 2. Low doses (1g of creatine monohydrate or less in water) produced only a modest rise in the plasma creatine concentration, whereas 5g resulted in a mean peak after 1h of 795 (SD 104) mumol/l in three subjects weighing 76-87 kg. Repeated dosing with 5g every 2h sustained the plasma concentration at around 1000 mumol/l. A single 5g dose corresponds to the creatine content of 1.1 kg of fresh, uncooked steak. 3. Supplementation with 5g of creatine monohydrate, four or six times a day for 2 or more days resulted in a significant increase in the total creatine content of the quadriceps femoris muscle measured in 17 subjects. This was greatest in subjects with a low initial total creatine content and the effect was to raise the content in these subjects closer to the upper limit of the normal range. In some the increase was as much as 50%. 4. Uptake into muscle was greatest during the first 2 days of supplementation accounting for 32% of the dose administered in three subjects receiving 6 x 5g of creatine monohydrate/day. In these subjects renal excretion was 40, 61 and 68% of the creatine dose over the first 3 days. Approximately 20% or more of the creatine taken up was measured as phosphocreatine. No changes were apparent in the muscle ATP content.(ABSTRACT TRUNCATED AT 250 WORDS) MESH: Administration,-Oral; Adult-; Creatine-administration-and-dosage; Creatine-blood; Creatine-urine; Middle-Age; Muscles-drug-effects MESH: *Creatine-metabolism; *Exercise-physiology; *Muscles-metabolism TG: Comparative-Study; Female; Human; Male; Support,-Non-U.S.-Gov't PT: JOURNAL-ARTICLE RN: 57-00-1 NM: Creatine AN: 93009547 UD: 9301
PhD Dissertations
Title: HIGH-INTENSITY INTERMITTENT EXERCISE: PERFORMANCE AND METABOLIC RESPONSES WITH VERY HIGH INTENSITY AND SHORT DURATION WORK PERIODS (CREATINE PHOSPHATE, GLYCOGEN, RECOVERY, OXYGEN) Author: BALSOM, PAUL DONALD School: KAROLINSKA INSTITUTET (SWEDEN) (0658) Degree: MEDDR Date: 1995 pp: 136 Source: DAI-C 56/03, p. 636, Fall 1995 Subject: BIOLOGY, ANIMAL PHYSIOLOGY (0433) ISBN: 91-628-1490-7 Publisher: REPRO PRINT AB, GALVEGATAN 12B, BOX 21085, S-100 31 STOCKHOLM, SWEDEN Location: PAUL BALSOM, KAROLINSKA INSTITUTE, PHYSIOLOGY III, BOX 5626, S-114 86 STOCKHOLM, SWEDEN </p> <p>Abstract: High intensity intermittent exercise represents an activity pattern similar to that seen in many sports, e.g., football, tennis and hockey, where periods of intense exercise are interspersed with periods of either active or passive recovery. The aim of this thesis was to evaluate how the different energy systems are utilised during this type of exercise with very high intensity ($/rm[>200]/%/ VO/sb2max$), short duration work periods ($[/le10]$ s) and to investigate metabolic factors which may be limiting performance. Highly motivated, physically active males were used as subjects in all studies. This type of exercise imposed very high energy demands on both anaerobic and aerobic metabolism. This was evident from low post-exercise levels of creatine phosphate (PCr), and high blood lactate concentrations which in some cases increased 20-fold above resting values. Even with work periods of less than 3 s in duration, there was on average a 7-fold increase in blood lactate concentration, suggesting that glycogenolysis and glycolysis had been stimulated close to the onset of exercise. Aerobic metabolism also made a significant contribution to the overall energy demand as indicated by values of oxygen uptake, which approached 70% VO$/sb2$max with repeated 6 s periods of work and 30 s periods of recovery. In addition to supplying energy to fuel the recovery processes, it is suggested that oxygen may also be utilised during work periods. The adenylate kinase reaction may have an important role during this type of exercise, as indicated by an increased accumulation of hypoxanthine in plasma and decreased levels of skeletal muscle adenine nucleotides. Performance, defined as the ability to maintain a high target power output during consecutive work periods, was found to be markedly influenced by only small changes in the exercise duration and intensity, and the duration of intervening recovery periods. Performance was impaired with low pre-exercise muscle glycogen concentration and when oxygen availability to the working muscles was reduced. On the other hand, following a regimen of creatine supplementation, which was shown to increase the total creatine concentration in m. vastus lateralis at rest, performance was enhanced. It is suggested that under conditions where the metabolic demands of the exercise causes a decline in power output after only a few work periods, substrate availability for anaerobic energy production may be a limiting factor for performance. However, the actual cause of fatigue was not elucidated. With a slightly lower, but still very high exercise intensity, where power output could be maintained for a more prolonged period of time, performance was limited by the availability of muscle glycogen, seemingly in much the same way as during continuous moderate intensity exercise. </p> <p>Order No: AAC 9618319 ProQuest -
Title: THE EFFECTS OF CREATINE SUPPLEMENTATION ON TOTAL WORK OUTPUT AND METABOLISM DURING HIGH-INTENSITY INTERMITTENT EXERCISE Author: PREVOST, MICHAEL CORY School: THE LOUISIANA STATE UNIVERSITY AND AGRICULTURAL AND MECHANICAL COL. (0107) Degree: PHD Date: 1995 pp: 116 Advisor: NELSON, ARNOLD G. Source: DAI-A 57/02, p. 621, Aug 1996 Subject: EDUCATION, PHYSICAL (0523); BIOLOGY, ANIMAL PHYSIOLOGY (0433) </p> <p>Abstract: The effects of creatine supplementation on endurance and metabolism during high intensity intermittent exercise was examined using 18 males and females (age 19-26). The subjects were randomly divided into 2 groups (creatine and placebo) and the testing proceeded in two phases. During phase 1 both groups received a placebo. During phase 2 the placebo group again received a placebo, while the creatine group received creatine. Testing consisted of a several high intensity intermittent cycling protocols on a stationary cycle ergometer. Both groups performed all test bouts (in random order) in phase 1 and again in phase 2. Testing consisted of: Continuous (Bout A)--Continuos pedaling at 150% VO2 peak until exhaustion. 30/60 (Bout B)--30 seconds of pedaling at 150% VO2 peak followed by 60 seconds rest, repeated until exhaustion. 20/40 (Bout C)--20 seconds pedaling at 150% VO2 peak followed by 40 seconds rest, repeated until exhaustion. 10/20 (Bout D)--10 seconds pedaling at 150% VO2 peak followed by 20 seconds rest, repeated until exhaustion. The placebo group showed no significant change in time to exhaustion from phase 1 to phase 2 for any of the bouts tested. The creatine group, however, showed a significant increase in time to exhaustion on all bouts. Bout D was impacted significantly pedaling at 150% VO2 peak followed by 20 seconds rest, repeated until exhaustion. The placebo group showed no significant change in time to exhaustion from phase 1 to phase 2 for any of the bouts tested. The creatine group, however, showed a significant increase in time to exhaustion on all bouts. Bout D was impacted significantly more than the other bouts with a more than twofold increase in time to exhaustion. (note that bout D was truncated before subjects reached exhaustion because even at twice the performance time of phase 1 subjects reported feeling very little fatigue and the ability to continue indefinitely). Oxygen consumption showed no change from phase 1 to phase 2 for the placebo group, while the creatine group showed a significantly lower rate of oxygen consumption on bouts D and C. Blood lactic acid values were also lower on bouts C and D for the creatine group only. Creatine supplementation also led to significantly increased urinary creatinine concentrations. Therefore creatine supplementation significantly impacted performance of high intensity intermittent exercise. </p> <p>Order No: AAC 9615793 ProQuest - Dissertation Abstracts
Title: THE INFLUENCE OF RECOVERY DURATION ON HIGH-INTENSITY EXERCISE PERFORMANCE AFTER ORAL CREATINE SUPPLEMENTATION Author: COOKE, WILLIAM HAROLD School: TEXAS A&M UNIVERSITY (0803) Degree: PHD Date: 1995 pp: 135 Advisor: BARNES, WILLIAM Source: DAI-A 57/01, p. 149, Jul 1996 Subject: EDUCATION, PHYSICAL (0523); BIOLOGY, ANIMAL PHYSIOLOGY (0433) </p> <p>Abstract: Acceleration of the rate of phosphocreatine resynthesis during recovery from exercise may underlie increases in work output reported for creatine-supplemented subjects during repeated exercise bouts. The purpose of this study was to determine the effects of creatine supplementation on the ability to reproduce and maintain a high percentage of peak power output during the 2nd of 2 bouts of high-intensity cycle sprinting following 4 different recovery intervals. Eighty healthy, active male subjects were randomly assigned to 1 of 2 Groups: creatine or placebo, and 1 of 4 recovery Intervals: (30, 60, 90 or 120 s). Power output was calculated on-line by computer as subjects pedaled as fast as possible against a fixed resistance (11 kg). A cut-off criterion of 30% decline from peak power was used to signal the end of each trial. Two maximal cycle ergometer sprints, separated by the assigned recovery interval were performed before and after a 5-d supplementation protocol in which 20 g/d of creatine or 20 g/d glucose placebo were ingested by creatine and placebo Groups, respectively. Maximal peak power output (PP) and the absolute time to fatigue (TTF) were compared pre- vs post-supplementation. Trial 2 PP means for subjects combined across Group and Time points (pre- vs post-supplementation) were significantly decreased with respect to Trial 1 following 30, 60, and 90 s recovery (p $<$.025). Non-significant differences between Trials 1 and 2 were noted for PP following 120 s recovery (p $>$.025). Significant differences between Trials 1 and 2 were found for TTF following all 4 recovery Intervals (p $<$.025). No significant Group interactions were noted in this study. Specifically, creatine supplementation had no effect on subjects' ability to reproduce or maintain a high percentage of PP during the 2nd bout of exercise following supplementation. It was concluded that creatine supplementation does not enhance the restoration and maintenance of power output following a fatiguing bout of high-intensity cycle exercise when a 2nd bout is performed following recovery durations thought to be most likely affected by a creatine-stimulatory effect on the rate of phosphocreatine resynthesis. </p> </body>