Biomaterial Database

Effect of creatine loading on long-term sprint exercise performance and metabolism. 2001

D Preen, and B Dawson, and C Goodman, and S Lawrence, and J Beilby, and S Ching

Department of Human Movement and Exercise Science, The University of Western Australia, Crawley, W.A., 6009, Australia. dpreen@mbox.com.au

OBJECTIVE This study examined whether creatine (Cr) supplementation could enhance long-term repeated-sprint exercise performance of approximately 80 min in duration. METHODS Fourteen active, but not well-trained, male subjects initially performed 10 sets of either 5 or 6 x 6 s maximal bike sprints, with varying recoveries (24, 54, or 84 s between sprints) over a period of 80 min. Work done (kJ) and peak power (W) were recorded for each sprint, and venous blood was collected preexercise and on four occasions during the exercise challenge. Muscle biopsies (vastus lateralis) were obtained preexercise as well as 0 min and 3 min postexercise. Subjects were then administered either 20 g.d-1 Cr.H2O (N = 7) or placebo (N = 7) for 5 d. Urine samples were collected for each 24 h of the supplementation period. Subjects were then retested using the same procedures as in test 1. RESULTS Total work done increased significantly (P < 0.05) from 251.7 +/- 18.4 kJ presupplementation to 266.9 +/- 19.3 kJ (6% increase) after Cr ingestion. No change was observed for the placebo group (254.0 +/- 10.4 kJ to 252.3 +/- 9.3 kJ). Work done also improved significantly (P < 0.05) during 6 x 6 s sets with 54-s and 84-s recoveries and approached significance (P = 0.052) in 5 x 6 s sets with 24-s recovery in the Cr condition. Peak power was significantly increased (P < 0.05) in all types of exercise sets after Cr loading. No differences were observed for any performance variables in the placebo group. Resting muscle Cr and PCr concentrations were significantly elevated (P < 0.05) after 5 d of Cr supplementation (Cr: 48.9%; PCr: 12.5%). Phosphocreatine levels were also significantly higher (P < 0.05) immediately and 3 min after the completion of exercise in the Cr condition. CONCLUSIONS The results of this study indicate that Cr ingestion (20 g.day-1 x 5 d) improved exercise performance during 80 min of repeated-sprint exercise, possibly due to an increased TCr store and improved PCr replenishment rate.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D010101	Oxygen Consumption	The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)	Consumption, Oxygen,Consumptions, Oxygen,Oxygen Consumptions
D010807	Physical Endurance	The time span between the beginning of physical activity by an individual and the termination because of exhaustion.	Endurance, Physical,Physical Stamina,Stamina, Physical
D010919	Placebos	Any dummy medication or treatment. Although placebos originally were medicinal preparations having no specific pharmacological activity against a targeted condition, the concept has been extended to include treatments or procedures, especially those administered to control groups in clinical trials in order to provide baseline measurements for the experimental protocol.	Sham Treatment
D003401	Creatine	An amino acid that occurs in vertebrate tissues and in urine. In muscle tissue, creatine generally occurs as phosphocreatine. Creatine is excreted as CREATININE in the urine.
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000284	Administration, Oral	The giving of drugs, chemicals, or other substances by mouth.	Drug Administration, Oral,Administration, Oral Drug,Oral Administration,Oral Drug Administration,Administrations, Oral,Administrations, Oral Drug,Drug Administrations, Oral,Oral Administrations,Oral Drug Administrations
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D012420	Running	An activity in which the body is propelled by moving the legs rapidly. Running is performed at a moderate to rapid pace and should be differentiated from JOGGING, which is performed at a much slower pace.	Runnings
D013647	Task Performance and Analysis	The detailed examination of observable activity or behavior associated with the execution or completion of a required function or unit of work.	Critical Incident Technique,Critical Incident Technic,Task Performance,Task Performance, Analysis,Critical Incident Technics,Critical Incident Techniques,Incident Technic, Critical,Incident Technics, Critical,Incident Technique, Critical,Incident Techniques, Critical,Performance, Analysis Task,Performance, Task,Performances, Analysis Task,Performances, Task,Task Performances,Task Performances, Analysis,Technic, Critical Incident,Technics, Critical Incident,Technique, Critical Incident,Techniques, Critical Incident