A primary objective in the weight room is to increase maximal strength in our athletes. This is because of the strong link between force production and factors such as performance, resistance to injury and even in limiting recovery time between sessions. Relative strength (i.e., 1RM/body mass) appears to be particularly important for speed and jumping activities. Maximal strength can be developed with both heavy (e.g. 1-5RM) and moderate loads (10-12RM) in individuals. Thus, it may seem that prescribing either repetition range would be sufficient for eliciting improvements in maximal force production. However, it isn’t entirely clear how factors such as barbell velocity and rate of force production (i.e., how fast we can express our strength) is impacted by training with heavy or moderate loads.
A new study published ahead of print in the European Journal of Applied Physiology compared the effects heavy versus moderate load strength training on various measures of strength and power in resistance-trained men. After a two-week preparatory/familiarization phase, 29 subjects were randomly allocated to a high intensity group (n=15, using 3-5RM loads, 3-minutes rest between sets) or a moderate intensity group (n=14, 10-12RM loads, 1 minute rest between sets). Both groups trained 4 times per week for 8 consecutive weeks and performed 4 sets of the same exercises (emphasizing the bench press and squat) in the same sequence. Before and after the training program all subjects were tested for 1RM in the bench press and squat along with 1RM barbell velocity. Additionally, maximal force and rate of force production at varying time points were evaluated with the isometric midthigh pull.
The results showed that after controlling for baseline values, there were significant differences in peak force and rate of force development in favor of the high intensity group at numerous time points (e.g., 30-200 ms for peak force and 50-90 ms for rate of force development). Barbell velocity during 1RM bench press and squat significantly improved similarly in both groups. Increases in 1RM squat were similar among groups, but the intensity group saw greater improvements in bench press strength. This study demonstrates that training with higher intensities is more effective than low intensities for improving isometric peak force and rate of force development. However, both programs similarly improved 1RM barbell velocity.
Mangine, G. T., Hoffman, J. R., Wang, R., Gonzalez, A. M., Townsend, J. R., Wells, A. J., … & LaMonica, M. B. (2016). Resistance training intensity and volume affect changes in rate of force development in resistance-trained men. European Journal of Applied Physiology, 1-8.