Over 55 years of critical power: Fact

We read with interest the paper by Gorostiaga et al.1 entitled “Over 55 years of critical power: Fact or artifact?”. It is our opinion, however, that the conclusions drawn by the authors (chiefly that critical power should be considered a mathematical artifact) stem from a grave misunderstanding of the critical power concept and its underlying physiology. The authors’ position is based upon a number of erroneous arguments (i) that critical power fails its own “definition” of being sustainable for “a long time without fatigue” (Monod & Scherrer, p.3292), (ii) use of arbitrary exercise durations to establish the power-duration curve (iii), that critical power approaches a high fraction of the speed or power providing the longest exercise duration, and (iv) critical power not residing at a fixed fraction of maximal oxygen uptake (V̇O2max) or maximal voluntary contraction (MVC).