Effects of a concurrent strength and endurance training on running performance and running economy in recreational marathon runners.

摘要

The purpose of this study was to investigate the effects of a concurrent strength and endurance training program on running performance and running economy of middle-aged runners during their marathon preparation. Twenty-two (8 women and 14 men) recreational runners (mean +/- SD: age 40.0 +/- 11.7 years; body mass index 22.6 +/- 2.1 kg.m(2)) were separated into 2 groups (n = 11; combined endurance running and strength training program [ES]: 9 men, 2 women and endurance running [E]: 7 men, and 4 women). Both completed an 8-week intervention period that consisted of either endurance training (E: 276 +/- 108 minute running per week) or a combined endurance and strength training program (ES: 240 +/- 121-minute running plus 2 strength training sessions per week [120 minutes]). Strength training was focused on trunk (strength endurance program) and leg muscles (high-intensity program). Before and after the intervention, subjects completed an incremental treadmill run and maximal isometric strength tests. The initial values for VO2peak (ES: 52.0 +/- 6.1 vs. E: 51.1 +/- 7.5 ml.kg(1).min(1)) and anaerobic threshold (ES: 3.5 +/- 0.4 vs. E: 3.4 +/- 0.5 m.s(1)) were identical in both groups. A significant time x intervention effect was found for maximal isometric force of knee extension (ES: from 4.6 +/- 1.4 to 6.2 +/- 1.0 N.kg(1), p < 0.01), whereas no changes in body mass occurred. No significant differences between the groups and no significant interaction (time x intervention) were found for VO2 (absolute and relative to VO2peak) at defined marathon running velocities (2.4 and 2.8 m.s(1)) and submaximal blood lactate thresholds (2.0, 3.0, and 4.0 mmol.L(1)). Stride length and stride frequency also remained unchanged. The results suggest no benefits of an 8-week concurrent strength training for running economy and coordination of recreational marathon runners despite a clear improvement in leg strength, maybe because of an insufficient sample size or a short intervention period.