Maximal effort, synonymous with point-of-failure, refers to moments during an activity where an athlete attempts to produce as much power as he/she has available.   Maximal effort and point-of-failure are synonymous because both instances define the convergence of MPA and power.  A maximal effort has the athlete attempting to sprint and generate as much power to reach MPA whereas a point-of-failure has the athlete attempting to hold on to power has MPA declines and reaches the desired power.  In both cases, from the perspective of the data, MPA and power are equal.

It’s possible to have either one maximal effort, or several maximal efforts during one activity. Below is an example of one maximal effort:

And here’s an example of a Zwift crit race that has several maximal efforts: