According to the principle of progressive resistance, in order to keep making gains over time, one must continually increase the weight loads used. Naturally, a training program will go from lighter weight and higher reps to heavier weight and lower reps. The increasing weight loads should ensure continued gains in strength and size.
Researchers from the University of Tsukuba in Japan took two groups and had them use two different training progressions. For the first six weeks, both groups used a program of nine total sets divided into groups of three sets. Thirty seconds of rest was taken for three sets, then three minutes was allowed for recovery before three more sets were performed. After six weeks, both groups switched to a traditional strength-training routine of five sets using 90% of their one-rep max (1RM) with three minutes’ rest between sets, with the exception of one group, who performed a quasidropset after the last set. This group was dubbed the “combi” group.
Both groups grew significantly during the first six weeks of using the higher-rep/short-rest style of training. After the switch to a more traditional style of strength training using 90% 1RM, only the combi group continued to grow for four more weeks.
A combination of both load stress and metabolic stress optimizes gains.
This study points out the importance of metabolic stress to optimize gains from resistance training. It’s important to increase the loads throughout a training cycle. When doing so, reps inevitably drop as the weight gets heavier and heavier. As a result, the metabolic stress is reduced as the number of reps decrease. In order to keep making size gains during the heavy phase of your training, add a high-rep set immediately following the last set of each exercise. This can be a single high-rep set using ~50% 1RM, or it can be more of a dropset where you keep grabbing a lighter weight each time you reach or get close to failure.