Athletic clients who want to increase their power output may be interested in the results of a study published in the 2003 Journal of Strength and Conditioning Research (volume 17). Researchers determined that alternating light and heavy resistances while training the upper body can significantly increase power output.
The study looked at 16 rugby players, who were experienced in power training and performed complex training on a regular basis. They were divided into two groups and were pre- and posttested on an explosive bench press throw, using a Smith machine. Pretesting showed no difference in power output. The experimental group used an intervention strategy of a six-repetition set of bench presses at 65 percent of one-repetition max while also using heavier resistances. The control group used only the heavier resistances. At posttesting a significant difference was observed between the two groups, with the experimental group demonstrating a 4.5 percent increase in power output.