The application of post-activation potentiation training has become more common among strength and conditioning circles. Preceding an explosive, high-velocity movement with a heavy set of strength work will transiently enhance performance by increasing power output, which may result in greater training adaptation. However, the majority of post-activation potentiation research focuses on lower body movements such as barbell back squats coupled with various jumping movements (e.g., drop-jump, countermovement-jump, depth-jump, etc.). In addition, the activation exercise is typically a traditional eccentric + concentric strength movement, or a supramaximal eccentric. Comparatively less research has been done for upper-body performance. Furthermore, the use of isometrics at varying intensities to induce a potentiation effect has also not been well studied.
A new study published ahead of print in the European Journal of Sport Science compared power outputs during the bench press following 3 different pre-activation conditions. A total of twenty-two resistance-trained men (~24 years old) performed bench press repetitions with maximal intended velocity at loads of 20%, 30%, 40% and 50% of their 1RM on three different occasions in a randomized fashion. At each occasion, the bench press sets were preceded by 1) a concentric contraction; 2) a low load isometric (70% 1RM) or; 3) a high load isometric (100% of 1RM).
The results showed that the high load isometric with 100% of 1RM resulted in significantly greater power outputs than traditional concentric only pre-activation, with +9%, +16% and +14% power at 20, 30 and 40% of 1RM, respectively. Similarly, the high load isometric condition resulted in significantly greater power outputs than the low load isometric condition, with +4%, +20% and +15% power at 20, 30 and 40% of 1RM, respectively. Interestingly, no significant differences were observed among any of the pre-activation conditions at 50% of 1RM. These results show that heavy isometrics performed before lower load explosive movements for the upper-body, result in greater power production. Isometrics may serve as a safer alternative to traditional, and supra-maximal eccentrics for inducing post-activation potentiation.
Reference:
Bartolomei, S. et al. (2016) The influence of isometric preload on power expressed during bench press in strength-trained men. European Journal of Sport Science. In press.
