Effect of creatine supplementation on sprint exercise performance and muscle metabolism

Abstract

The aim of the present study was to examine the effect of creatine supplementation (CrS) on sprint exercise performance and skeletal muscle anaerobic metabolism during and after sprint exercise. Eight active, untrained men performed a 20-s maximal sprint on an air-braked cycle ergometer after 5 days of CrS [30 g creatine (Cr) + 30 g dextrose per day] or placebo (30 g dextrose per day). The trials were separated by 4 wk, and a double-blind crossover design was used. Muscle and blood samples were obtained at rest, immediately after exercise, and after 2 min of passive recovery. CrS increased the muscle total Cr content (9.5 +/- 2.0%, P < 0.05, mean +/- SE); however, 20-s sprint performance was not improved by CrS. Similarly, the magnitude of the degradation or accumulation of muscle (e.g., adenine nucleotides, phosphocreatine, inosine 5'-monophosphate, lactate, and glycogen) and plasma metabolites (e.g. , lactate, hypoxanthine, and ammonia/ammonium) were also unaffected by CrS during exercise or recovery. These data demonstrated that CrS increased muscle total Cr content, but the increase did not induce an improved sprint exercise performance or alterations in anaerobic muscle metabolism.

Influência da suplementação de creatina na capacidade funcional de pacientes com Insuficiência Cardíaca

“…Contrary to the results of previous studies, another study carried out with eight healthy, untrained individuals, supplemented with creatine, using a 20-second sprint cycle ergometer, even in the presence of an increased muscle CP content, has shown neither exercise performance improvement nor changes in the muscle anaerobic metabolism 36 . Stroud et al 37 , studying the effect of creatine supplementation (4 g for five days) on more prolonged exercises in healthy individuals, have assessed peak VO 2 during a 10-km walk on a treadmill and have found no significant difference.…”

Influence of creatine supplementation on 800 m wheelchair performance: a pilot study

“…Most studies investigated the influence of creatine supplementation on leg muscle performance. [1][2][3][4][5][6]8,9,16,[24][25][26] Since arm muscles contain more type II fibres than leg muscles and since type II fibres have initially a higher phosphocreatine content than type I fibres, 15 it could be hypothesised that creatine supplementation would be less efficient for arm exercise, an assumption that is supported by our findings. However, this hypotesis has to be investigated in further studies, as one cannot conclude definitely if an initially higher phosphocreatine content of arm muscles limits the effectiveness of a creatine supplementation in this muscle group.…”

“…Moreover, lactate concentrations were not influenced by creatine supplementation in the present study, which supports the hypothesis that the glycolytic pathways were unaltered by creatine supplementation as proposed by Birch et al 2 Many studies in the past reported positive effects on performance of different types and durations after a short-term creatine supplementation, [1][2][3][4][5][6][7][8]21 whereas others found no effect. 16,[22][23][24][25][26] Interestingly, in most of the studies showing no ergogenic effect on exercise performance after creatine supplementation, a time or distance trial was performed, [22][23][24][25][26] whereas in studies with a positive effect the time to exhaustion at a given workload was determined. 3,8,9,21 This type of exercise test depends mainly on metabolism and remaining energy stores, whereas during time trials higher movement frequencies are required to improve test results.…”

The Biomechanic Origin of Sprint Performance Enhancement after One-Week Creatine Supplementation.

“…Many studies did not observe any particular ergogenic effect of exogenous Cr on performance during single sprint protocols [1,[11][12][13]. We anticipated that exogenous Cr would be ergogenic for anaerobic exercise mainly when the effect of fatigue appears.…”