7 ± 4.7% and +0.5 ± 2.1% in the creatine and placebo groups, respectively (P = N.S.). Changes in plasma volume from pre- to post-supplementation were significantly greater in the creatine group (+14.0 ± 6.3%) than the placebo group (-10.4 ± 4.4%; P < 0.05) at 90 minutes of exercise. Figure 5 a and b - Mean hemoglobin (Figure 5a) and hematocrit (Figure 5b) selleck chemical during approximately 2-hours of cycling performed before and at the end of 28 days
of dietary supplementation (3 g/day creatine; n = 6 or placebo; n = 6) in young trained cyclists. Arrows denote sprint bouts. Data are presented as mean ± SEM. +pre creatine different from pre placebo. selleck kinase inhibitor muscle creatine, total creatine, creatine phosphate, and adenosine triphosphate Resting muscle total creatine concentrations (Figure 6a) were higher in the creatine than placebo groups both before and after supplementation, although muscle total creatine increased following supplementation in both groups. When calculating the increase in muscle creatine for each individual pre- to post-supplementation, the mean increase in muscle total creatine was 24 ± 11% in the creatine group and 15 ± 3% in the
placebo group (p = N.S.). Figure 6 a-d. Mean muscle selleckchem total creatine (Figure 6a), creatine phosphate (Figure 6b), creatine (Figure 6c), and muscle ATP (Figure 6d) during approximately 2-hours of cycling performed before and at the end of 28 days of dietary supplementation (3 g/day creatine; n = 6 or placebo; n = 6) in young trained cyclists. Data are presented as mean ± SEM. *creatine different from corresponding placebo. + post different from pre. Muscle creatine phosphate (CP; Figure 6b) at rest was not different between creatine and placebo groups prior to supplementation, although muscle very CP was higher following supplementation in the creatine than placebo group (P < 0.05). When calculating the increase in muscle CP during supplementation on an individual basis, the increase in resting muscle CP was 38 ± 27% in the creatine group and 14 ± 11% in the placebo group. There was a significant drop in muscle CP
by the end of the two-hour ride after supplementation in the placebo group (P < 0.05), although this drop was not as evident in the creatine group (Figure 6b). There was no correlation between the change in muscle creatine phosphate and the change in sprint performance from pre- to post-supplementation. Resting muscle creatine concentration (Figure 6c) was increased by supplementation in the creatine group (P < 0.05). Muscle creatine concentration was increased (P < 0.05) to a similar extent during the two-hour cycling bout in creatine and placebo groups. With respect to muscle ATP content (Figure 6d), there was a significant main effect for time, in that there was a drop in muscle ATP over the two-hour cycling bout prior to supplementation that was not seen following supplementation in either creatine or placebo groups.