A biomechanical analysis of the acute effects of complex training using lower limb exercises

The aim of this study was to investigate the current practice of complex training using a lower body combination of exercises. It was hypothesized that a bout of heavy resistance exercise (HRE), as typically used in complex training, would lead to enhanced performance (in the form of counter-movement [CMJ] and drop [DJ] jump height) and increased electromyographical (EMG) activity in subsequent plyometric exercise, also typical of complex training. Eight strength trained men performed 2 conditions: HRE or control (no-HRE) in a counter-balanced order. Both conditions involved 4 sets of 6-jump trials (3-CMJ/ 3-DJ). The first set of jumps was used as a baseline. For the HRE condition, 5-squats at 85% of 1 repetition maximum (1RM) followed shortly after the first set, while the second, third and fourth sets followed at 3-, 10-, and 20-minutes post-HRE, respectively. The control condition involved the same procedure, but no exercise separated the first 2-sets. There were no significant main effects (p > 0.05) for any CMJ performance variable or EMG activity regardless of muscle or phase of jump. There were no significant (p > 0.05) main effects of heavy resistance exercise on DJ performance variables. Only the biceps femoris during the propulsive phase of the DJ was significantly higher (p < 0.05) following HRE compared to no-HRE. Some trends in the data were evident and the power of the statistical tests was low. It was concluded that no evidence was found to support the experimental hypothesis although the absence of a treatment effect could not be ruled out. From a practical point of view, undertaking a bout of HRE had no adverse effects on subsequent plyometric performance and so some of the advantages of complex training still remain.