Author(s): WE, H., PARK, J.H., YUN, S., SEO, Y., LEE, Y., LEE, S.H., SON, S., LEE, D.T., Institution: KOOKMIN UNIVERSITY, Country: KOREA, SOUTH, Abstract-ID: 966

INTRODUCTION:
The purpose this study was to analyze the relationships between the rest interval between sets and the repetitions during bench press.
METHODS:
Fifteen healthy young men (23.6±2.2 yrs, 174.8±3.4 cm, 76.2±10.2 kg, 24.9±3.2 kg/m2, 1 repetition maximum (1RM) 75.9±19.3 kg) participated in 3 separate bench press testing sessions. In each session, they performed 3 sets at 70% weight of their 1 RM and were asked to rest 2 (2-RI), 5 (5-RI), or 10 min (10-RI) between sets. They were also asked to repeat at their best for each set, and the repetitions were counted. Differences between rest intervals and between sets were compared using one-way ANOVA and paired t-test, respectively. Correlations in repetition between rest intervals were examined using Pearson correlation.
RESULTS:
The repetitions were 17.9±5.1, 7.7±3.0, and 5.1±2.7 in 2-RI, 17.3±3.9, 11.9±3.8, and 9.1±3.5 in 5-RI, and 17.3±3.8, 15.1±4.3, and 12.4±3.6 reps in 10-RI during the 1st, 2nd, and 3rd sets, respectively. The decrements of repetition from the 1st to the 2nd sets were significantly greater in the order of 2-RI (11.7±3.6, p<0.001), 5-RI (7.5±3.1, p<0.001), and 10-RI (4.3±2.2 reps, p<0.05). Accordingly, the percentile decrements of repetition from the 1st to the 2nd sets were greater in the order of 2-RI (60±13, p<0.001), 5-RI (39±15, p<0.001), and 10-RI (23±11%, p<0.005). No differences in repetition between the 2nd and the 3rd sets were noticed in all rest intervals. But the percentile decrements of repetition from the 2nd to the 3rd sets were greater in 2-RI (36±18) than 10-RI (17±15%) (p=0.005). When the magnitude of decrements from the 1st to the 2nd sets were compared, 2-RI and 5-RI were highly correlated (r=0.788, p<0.001). But no relationships were found between 2-RI and 10-RI (r=0.238) or 5-RI and 10-RI (r=0.426).
CONCLUSION:
The repetitions of bench press during the 2nd set at 70% of 1 RM was affected by the rest interval between sets, but those during the 3rd set was not so. Nonetheless, the percentile decrements were affected by the rest interval. The rest interval may influence the repetitions of the following set, but it appeared to be not the case at the 10 minutes interval. It is of interest that these observations are consistent in other weights and other types of resistance exercise.