Determinants of repeated-sprint ability in females matched for single-sprint performance

This study investigated the relationship between VO2max and repeated-sprint ability (RSA), while controlling for the effects of initial sprint performance on sprint decrement. This was achieved via two methods: (1) matching females of low and moderate aerobic fitness (VO2max: 36.4 ± 4.7 vs 49.6 ± 5.5 ml kg−1 min−1 ; p < 0.05) for initial sprint performance and then comparing RSA, and (2) semi-partial correlations to adjust for the influence of initial sprint performance on RSA. Tests consisted of a RSA cycle test (5×6-s max sprints every 30 s) and a VO2max test. Muscle biopsies were taken before and after the RSA test. There was no significant difference between groups for work (W 1, 3.44 ± 0.57 vs 3.58 ± 0.49 kJ; p = 0.59) or power (P 1, 788.1 ± 99.2 vs 835.2 ± 127.2 W; p = 0.66) on the first sprint, or for total work (W tot, 15.2 ± 2.2 vs 16.6 ± 2.2 kJ; p = 0.25). However, the moderate VO2max group recorded a smaller work decrement across the five sprints (W dec, 11.1 ± 2.5 vs 7.6 ± 3.4%; p = 0.045). There were no significant differences between the two groups for muscle buffer capacity, muscle lactate or pH at any time point. When a semi-partial correlation was performed, to control for the contribution of W 1 to W dec, the correlation between VO2max and W dec increased from r = −0.41 (p > 0.05) to r = −0.50 (p < 0.05). These results indicate that VO2max does contribute to performance during repeated-sprint efforts. However, the small variance in W dec explained by VO2max suggests that other factors also play a role