Effects of Resistance Training on H+ Regulation, Buffer Capacity, and Repeated Sprints

Purpose: We investigated the effects of resistance training on muscle buffer capacity, H+ regulation, and repeated-sprint ability (RSA). Methods: Sixteen recreationally active females performed a graded exercise test to determine V˙O2peak and the lactate threshold (LT), a repeated-sprint test (5 × 6 s, every 30 s) to determine RSA, and a 60-s high-intensity exercise test based on their pretraining RSA score (CIT60; continuous cycling at approximately 160% V˙O2peak). Muscle biopsies (vastus lateralis) were sampled before and immediately after CIT60. Subjects were then randomly assigned to either a high-repetition (three to five sets of 15-20 reps) short-rest (20 s) resistance-training group or to a control group. Results: Training did not result in significant improvements in V˙O2peak (P > 0.05) but did improve the LT, leg strength, and RSA (P < 0.05). There were no significant improvements in muscle buffer capacity after training (P > 0.05); however, there was a significant reduction in H+ in the muscle and blood after high-intensity exercise (CIT60) (P < 0.05), Conclusions: High-repetition, short-rest, resistance training does not improve muscle buffer capacity in active females, but it does reduce H+ accumulation during high-intensity exercise (~160% V˙O2peak). It is likely that increases in strength, LT, and ion regulation contributed to the improved RSA.