And the series on what is muscular failure continues. In the weight room part 2, I looked the issue of the Repetition Maximum (RM), defined as the maximum number of repetitions completed prior to reaching failure during a set. In the strictest sense this means that RM should always be one repetition less than the number of reps that resulted in muscular failure. If you failed, or would have failed, on repetition 13, then that is a 12RM.
That led into actual definitions of muscular failure. I started with the strictest physiological definition which is the point at which muscular force output falls below muscular force requirements (noting again that this is not synonymous with exhaustion). Once again I present my lovingly drawn image.