Strength athletes who want to make their upper body stronger, will train their upper muscle groups with heavy weights. The muscles in their lower body, on the other hand, they ca.n better train with lighter weights. This is shown by a human study published by sports scientists at the University of Central Florida in the Journal of Strength & Conditioning Research. Study The researchers divided 20 men aged 18-35, who had been training with weights for a long time, into 2 groups - an HI group and an MP group. All men had about the same training schedule. They did as much of the same exercises on the same days. HP The men in this group trained all their muscle groups with 88-90 percent of the load with which just 1 rep was possible [1 repetition maximum]. With that weight they made 4 to 5 reps. MP The men in this group trained their lower body muscle groups with 65-70 percent of the load with which just 1 rep was possible. With that weight they made 10-12 reps. The men trained their upper body muscle groups like the HI group. Results The MP group got stronger at the bench press than the HI group did. In the MP group the 1 rep maximum increased the most in the MP group. The power - say: the speed - that the men could develop at the bench press, increased the most in the MP group as well. Conclusion "The results of this study confirm the hypothesis that lower body training can affect upper-body adaptations to a high-intensity training program in experienced, resistance-trained men", the researchers wrote. "Results of this study provide evidence to support the use of different training schemes for upper and lower body during the same training period for optimizing upper body adaptations in men." "In particular, greater improvements in upper body maximal strength and power can be achieved using high-volume training programs to optimize upper body adaptations to resistance training." "It also may provide support for the use of a multifocal approach to program design, similar to what may be used in nonlinear training programs." Source: J Strength Cond Res. 2018 Jan;32(1):13-8.