Figure 1.
Schematic representation of the experimental design (10×6-s/30-s ten sprints of 6 s in duration each interspersed with 30 s of recovery; 5×6-s/30-s five sprints of 6 s in duration each interspersed with 30 s of recovery).
A total of three muscle biopsies was obtained from each subject during the muscle biopsy condition.
Figure 2.
Average peak power output (A), total work done (B) and EMG amplitude (root mean square) (C) of the vastus lateralis muscle for the entire group over the 15 sprints.
Data are presented as means ± SEM, expressed as a percent of sprint 1 (n = 8).
Figure 3.
Total work done during five consecutive sprints (full bar height, TW5SPT) and the initial sprint (height of the dark lower portion, TW1SPT).
The difference between these respective mechanical works is illustrated by the white upper portion of the bar. Numeric values (mean ± SEM) for the ratio of TW5SPT/TW1SPT appear within the bars. Data for the bars are mean values and are presented as Joules per kilogram body mass (n = 8). * Significant differences between the ratios, P<0.05.
Table 1.
Muscle ATP, PCr, Lac, H+ and pH in the vastus lateralis muscle at rest (Pre), following the completion of ten, 6-s cycling sprints interspersed with 30 s of recovery (Post 0), and after 6 min of recovery (Post 6).
Figure 4.
Evolution of the total work done (TW, black column), EMG root mean square of the vastus lateralis muscle (RMS, white column), and TW/RMS ratio (cross-hatch column) for the entire group over selected sprints.
Data are presented as means ± SEM, expressed as a % of sprint 1 (n = 8). * Significantly different from Sprint 1, P<0.05; † Significantly different from Sprint 10, P<0.05; § Significantly different from Sprint 10, P<0.05.
Figure 5.
Muscle phosphocreatine (PCr) recovery following the 6 min of passive recovery was positively related to: A) the total work done during sprint 11 (r = 0.79, P<0.05) and, B) the total work done across the five consecutive sprints (r = 0.67, P<0.05).