When people lift weights, whether they do the lifting part slowly or the lowering part slowly, or train until they can't do another rep, it doesn’t make much difference in how much their muscles grow — and sometimes the difference is so small it might not even matter.

When people lift weights, changing how fast they lift or lower the weight, or whether they go all the way to exhaustion, doesn’t seem to make a big difference in muscle growth—any differences are tiny and not very clear.

How fast or slow you lift and lower weights probably doesn’t make much difference in how much muscle you build—but it might matter a little depending on whether you’re pushing down, pulling up, working a specific body part, or going all the way to exhaustion.

How fast or slow you lift and lower weights probably doesn’t make much difference in how much muscle you build—unless there’s some special situation we haven’t figured out yet.

How fast or slow you lift and lower weights probably doesn’t make much difference in building muscle—unless you’re doing something very specific, but we’re not sure what that is yet.

Individual hypertrophic responses to resistance training are highly variable across muscle groups and are not consistently correlated between upper and lower body musculature.