Lets say I am maxing out some athletes and I decide I want to find out each athletes fiber composition of a muscle group. I read in an article by Jason Karp that after determining an athletes 1RM, have them perform as many reps at 80% of their 1RM to failure. Essentially the more reps you can do, the more ST fibers you are likely to have, and vice versa.
First of all is this true? And secondly, if I were to use this test, would I have them perform the reps at 80% on that same day, or over the course of a few days or a week?
I think Jason is a sharp physiologist but I think this test is bogus. First, it’s going to give such a broad range that it wouldn’t be useful.
More importantly, what’s the point? There’s so many more factors that influence performance than just fiber type – training, metabolic conditioning, enzymatic efficiencies, etc. So knowing fiber type (even from a legitimate test like a biopsy) doesn’t mean anything outside of a research or clinical setting without considering all the other factors.