Doing five or six sets of strength exercises instead of four, when pushing close to muscle failure, does not lead to meaningfully more muscle growth.

We analyzed the available evidence on whether increasing resistance exercise sets from four to five or six leads to more muscle growth, and what we’ve found so far suggests no meaningful difference. One assertion directly examined this comparison, finding that when training close to muscle failure, doing five or six sets instead of four does not result in meaningfully greater muscle growth [1]. This single assertion is supported by 54 studies or data points, with none contradicting it. The evidence we’ve reviewed does not show that adding extra sets—beyond four—leads to noticeably better muscle gains under conditions where effort is high and form is maintained. This doesn’t mean more sets are useless, but rather that the additional volume may not translate to extra growth when intensity is already high. It’s possible that for some people, more sets could help with motivation, endurance, or recovery adaptation, but the direct impact on muscle size appears limited based on this analysis. We don’t know if this holds true for beginners, advanced lifters, or different muscle groups, since the evidence we’ve reviewed doesn’t break it down that way. What we can say is that, at least in the context of training near failure, going from four to five or six sets doesn’t appear to make a meaningful difference in muscle growth. If you’re already doing four hard sets per exercise, adding one or two more may not be necessary for building more muscle—unless you enjoy the extra work or find it helps you stay consistent.