Does resistance exercise lifting velocity change with different rest intervals?

Abstract

In this study, we examined the sex difference of the effect of rest intervals on lifting velocity during resistance exercise. Twenty-two trained subjects (11 men and 11 women) were included. Each protocol consisted of 3 sets of 10 repetitions at 70% of 1- repetition maximum (1RM) with rest intervals of 90 s (R90), 150 s (R150), and 240 s (R240) in a crossover design. The exercise did parallel squats with free weights. The measurement items are lifting velocity (mean velocity) in each repetition and blood lactate concentration after exercise. There was a significant interaction between changes in the average velocity of 10 repetition in each set (AV<inf>10rep</inf>) and sex in each protocol, indicating that AV<inf>10rep</inf> during squat exercise has decreased in men but not in women in each protocol (P=0.002-0.03). Our results suggested that short rest intervals will not recover lifting velocity between short rest intervals until the next set at men, while women will be able to recover even with short rest intervals.