Repetition Failure is a Key Determinant of Strength Development in Resistance Training

Abstract

0395 Although resistance training to repetition failure appears necessary for strength and power development, debate continues over the optimal number of repetitions per set, rest duration, and volume for strength development. PURPOSE: To compare the effect of different set designs and volume on the magnitude of strength development when training to repetition failure. METHODS: Elite junior basketball players (n = 12, 18.6 ± 0.4 yr, 96.5 ± 11.7 kg) and senior volleyball players (n = 10, 24.4 ± 3.0 yr, 92.7 ± 8.6 kg) were tested on 6- and 3- repetition maximum (RM) mass of bench press, and 40kg Smith Machine bench press throw power (BT). For six weeks, groups trained either 4 sets of 6 repetitions every 121 seconds (4 × 6), 8 sets of 3 repetitions every 72 seconds (8 × 3), or 12 sets of 3 repetitions every 72 seconds (12 × 3). All groups trained at progressively increasing intensity between 90%–100% of their 6RM to ensure repetition failure by the end of each training session. Subjects were then re-tested on 6RM and 3RM bench press, and BT. Smallest worthwhile changes were calculated as: 6RM (2.1kg, 2.6%), 3RM (2.1kg, 2.5%) and BT (36 watts, 4.5%). RESULTS: The 4 × 6 and 12 × 3 groups reached repetition failure on more training repetitions (4.4 and 3.6 repetitions, p < 0.01) per session than the 8 × 3 group (2.0 repetitions). Significant improvements over the six-weeks of training were observed in 6RM (4.9kg, 95%CL: 3.3 – 6.5), 3RM (4.6kg, 3.2 – 6.1) and BT (88w, 50 – 118) (all p < 0.01) with no significant difference between groups (6RM, p = 0.41; 3RM, p = 0.56; BT, p = 0.24). CONCLUSIONS: The amount of repetition failure did not determine the magnitude of strength gains. Set and rest duration, set volume, nor the number of repetitions missed substantially affected the magnitude of the strength gains when repetition failure was reached.