The effects of power training are substantially increased by traditional power training at 75% of 1 RM, taxing the muscles first at 20% of 1RM until exhaustion. By this way of training, the maximum strength compared to only traditional power training improved by more than 18%, the cross section of the muscle by 9%, and muscle endurance by 17%.
The ultimate effect of power training depends on many factors including the resistance, the speed of execution, the number of repetitions, the number of sets and the rest between the sets. For increasing the muscle mass it is often advised to perform three sets of 8-12 repetitions at 75% of 1RM. However, there are also indications that power training with a substantially lower resistance can lead to an increase in the muscle mass. This could be explained by the fact that during strength training with low resistance the type I muscle fiber are contracting. Because of the low resistance is it possible to carry out many repetitions before mainly the type I muscle fibers become exhausted and the type II muscle fibers are more and more activated.
By training in this way the type II muscle fibers are also trained at a relatively low resistance. Brazilian researchers have now investigated the effect of carrying out an exhaustive exercise, with a low resistance just prior to standard power training.
In this study 27 untrained men of about 21 years old participated. The subjects were divided equally into three groups of which two performed power training and one served as a control group. Both training groups performed the same exercise of their knee extensors (m. Quadriceps femoris) for 8 weeks 2 times per week. The load during each training was 3 sets of 8-12 repetitions at 75% of 1RM with 1 minute rest between the sets. The only difference between the two groups was that one group just before the standard training carried out one set of repetitions until exhaustion at 20% of 1RM. Every 15 days, the resistance was individually adapted. Before and after the training period, the maximum force, the cross section of the muscle, and the muscle endurance were measured. In addition, the muscle activation was also measured by EMG. The group that had executed 1 set to exhaustion prior to the standard training achieved greater effects on all measured outcomes after eight weeks of training. For example, in comparison to the group that only did the standard training, the maximum force had increased more (44% vs. 27%), the cross section of the muscle increased more (21% vs. 12%) and the muscle endurance increased more (51% vs. 31%). In addition, 20% less muscle activity was measured during the muscular endurance test, suggesting an improved efficiency of activation (recruitment).
Based on this study, it definitely seems worth trying, first to perform one set with low resistance to exhaustion before a standard power training.