The Effects of Muscle Mass and Number of Sets During Resistance Exercise on Postexercise Hypotension

Polito, MD and Farinatti, PTV. The effects of muscle mass and number of sets during resistance exercise on postexercise hypotension. J Strength Cond Res 23(8): 2351-2357, 2009-The effects of muscle mass and number of sets on postexercise hypotension (PEH) following resistance exercises are barely known. The aim of the study was to compare systolic blood pressure (SBP), diastolic blood pressure, and mean arterial blood pressure (MAP) after biceps curl and leg extension with different number of sets. Twenty-four trained men (23 ± 1 year, 69 ± 4 kg, 173 ± 3 cm) were randomly assigned into control group, arm group, and leg group. On the first day, the 12 repetition maximum (12RM) workload was determined for both experimental groups. In the remaining days, arm group and leg group performed, randomly, 6 or 10 sets of 10 repetitions of the respective exercises at 12RM workload. Blood pressure was assessed before and every 10 minutes after the exercises for 1 hour. The 3-way analysis of variance identified a significant influence of the type of exercise (p = 0.000001), number of sets (p = 0.007), and postexercise period (p = 0.009) on SBP and of the type of exercise (p = 0.03) on MAP. No differences were found among the groups at rest. Postexercise hypotension was only observed for the leg group when 10 sets were performed. In this group, SBP was significantly (p ≤ 0.05) lower than at rest during all the observation periods (120.6 ± 2.7 vs. 107.1 ± 3.2 to 113.4 ± 2.8 mm Hg) and MAP was significantly lower than at rest only for the 30-minute assessment (90.3 ± 2.1 vs. 85.1 ± 1.5 mm Hg). It is therefore possible that the muscle mass activated during resistance exercise has an influence on PEH, especially in high-volume multiple-set training sessions.