Effects of Oral Creatine-Pyruvate Supplementation in Cycling Performance

Abstract

A double-blind study was performed to evaluate the effects of oral creatine-pyruvate administration on exercise performance in well-trained cyclists. Endurance and intermittent sprint performance were evaluated before (pretest) and after (posttest) one week of creatine-pyruvate intake (Cr(pyr), 2 x 3.5 g x d-1, n = 7) or placebo (PL, n = 7). Subjects first performed a 1-hour time trial during which the workload could be adjusted at 5-min intervals. Immediately they did five 10-sec sprints interspersed by 2-min rest intervals. Tests were performed on an individual race bicycle that was mounted on an ergometer. Steady-state power production on average was about 235-245 W, which corresponded to blood lactate concentrations of 4-5 mmol x l -1 and heart rate in the range of 160-170 beats x min -1. Power outputs as well as blood lactate levels and heart rates were similar between Cr(pyr) and PL at all times. Total work performed during the 1-h trial was 872 +/- 44 KJ in PL versus 891 +/- 51 KJ in CR pyr. During the intermittent sprint test power peaked at about 800-1000 watt within 2-3 sec, decreasing by 15-20 % towards the end of each sprint. Peak and mean power outputs were similar between groups at all times. Peak lactate concentrations after the final sprint were approximately 11 mmol x l -1 in both groups during both the pretest and the posttest. It is concluded that one week of creatine-pyruvate supplementation at a rate of 7 g x d -1 does not beneficially impact on either endurance capacity or intermittent sprint performance in cyclists.

Creatine Supplementation Reduces Muscle Inosine Monophosphate during Endurance Exercise in Humans

“…The present study supports that finding because Cr supplementation attenuated the rise in muscle energy imbalance during the performance ride but did not affect the ability to increase power output during approximately 15 min of exercise following 45 min of exercise at approximately 80% V O 2peak . We anticipated that Cr supplementation would not influence endurance exercise performance because others have found no effect of Cr supplementation on prolonged (8 -60 min) exercise performance (1,2,28). It should be noted, however, that a type 1 error may exist in our performance data because a small number of individuals was studied using a performance measure with a relatively large coefficient of variation of 3.5%.…”

“…These improvements are thought to be caused largely by the increases in muscle total Cr, and particularly Cr phosphate, which makes a major contribution to adenosine triphosphate (ATP) resynthesis during such exercise (7,8). On the other hand, Cr supplementation does not appear to influence endurance exercise performance (1,2,28). Indeed, recently it was shown that 1-h time trial exercise performance is not influenced by Cr supplementation in trained cyclists (2).…”

The effect of creatine supplementation upon inflammatory and muscle soreness markers after a 30km race

“…One of the most widely used supplements for ergogenic purposes is creatine (Lawler et al, 2002). Creatine, when supplemented for short-time periods, improves performance during repeated bouts of high intensity exercise (review in Mujika and Padilla, 1997;Kreider, 2003), while there is a lack of an ergogenic effect of creatine supplementation in a variety of endurance exercise protocols (van Loon et al, 2004;Van Schuylenbergh et al, 2003;Izquierdo et al, 2002).…”

Creatine Supplementation and Athletic Performance

“…8,29,55,56 Performance in running sprints was improved in most, 8,14,25,29 but not all studies, 40 and inconsistent results have been observed for cycling sprint performance, with benefits observed in several studies, 7,11,15,16,47,58 while not in others. 12,17,49,52,53 Cr supplementation generally has not been associated with improvements in endurance exercise performance, 16,29,52 or a reduction in muscle damage with high-intensity exercise. 44 Some of the discrepancies between study results may be attributable to differences in study design, including the sex, age, and training status of the subjects (untrained individuals versus elite athletes), the sport for which athletes were trained, Cr dose and duration of supplementation (3 days-12 weeks), and the exercise tests used to assess benefits.…”