Jump height is a poor indicator of lower limb maximal power output: theoretical demonstration, experimental evidence and practical solutions
Lower limb maximal power output (Pmax) is a key physical component of performance in many sports. During squat jump (SJ) and countermovement jump (CMJ) tests, athletes produce high amounts of mechanical work over a short duration to displace their body mass (i.e. the dimension of mechanical power). Thus, jump height has been frequently used by the sports science and medicine communities as an indicator of Pmax. However, in this article, we contended that SJ and CMJ height are in fact poor indicators of Pmax in trained populations.
To support our opinion, we first detailed why, theoretically, jump height and Pmax are not fully related. Specifically, we demonstrated that individual body mass, distance of push-off, optimal loading and force-velocity characteristics confound the jump height-Pmax relationship.
We also discussed the poor relationship between SJ or CMJ height and Pmax measured with a force plate based on data reported in the literature, which added to our own experimental evidence.
Finally, we discussed the limitations of existing practical solutions (regression-based estimation equations and allometric scaling), and advocated using a valid, reliable and simple field-based procedure to compute individual Pmax directly from jump height, body mass and push-off distance. The latter may allow researchers and practitioners to reduce bias in their assessment of Pmax by using jump height as an input with a simple yet accurate computation method, and not as the first/only variable of interest.