You'll get more progression if you do a long set at the end of a training session
If you train for strength, and do sets with heavy weights and few reps, you'll build up more muscle mass and strength by finishing your workout with one set using less weight but more reps. Sports scientists at the University of Tsukuba wrote about this in 2004 in the Journal of Strength and Conditioning Research.
Sets with 60 percent of our 1RM [the weight with which you can just manage 1 rep] increase your growth hormone production. That's why the researchers wondered whether strength training would be more effective if you finish off by doing a set with relatively light weights but as many reps as possible.
The researchers devised an experiment with 17 male students. They got the students to train their legs twice a week on the leg-press and leg-extension machines. For the first six weeks the students followed a hypertrophy-oriented scheme [H type].
The hypertrophy phase came to an end after 6 weeks. Because the students were 'fresh' they showed impressive progress in the hypertrophy phase. In the second phase, the 4-week long strength phase, they progressed more slowly.
The researchers split the students up into one group that followed a strength-oriented scheme [S type; HS]. The students in this group trained with weights of 90 percent of their 1RM. A second group did the same training, but finished off with one long set [Combi type; HC].
The figure below shows that finishing off the strength workout with a longer set leads to an increase in the 1RM, and increased growth of the leg muscle mass [CSA]. The figure underneath shows that, during the first 60 minutes after the workout finished, the growth hormone synthesis increases more if you finish off the strength training with one long set.
"The present results demonstrated the effects of an additional set of low-intensity exercise immediately after a high-intensity, low-repetition exercise in gaining muscular strength and endurance, suggesting its usefulness in the strength protocol", the researchers conclude. "The present regimen with combined high- and low-intensity resistance exercises may be useful, at least occasionally, in various kinds of sports that require muscular strength and endurance simultaneously."
J Strength Cond Res. 2004 Nov; 18(4): 730-7.
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