Potential Energy as an Alternative for Assessing Lower Limb Peak Power in Children: A Bayesian Hierarchical Analysis

The aim of this study was to analyze the use of potential energy (PE) as an alternative method to assess peak power of the lower limbs (PP) in children. 815 Spanish children (416 girls; 6-11 years old; Body Mass Index groups (n): underweight = 40, normal weight = 431, overweight = 216, obese = 128) were involved in this study. All participants performed a Countermovement Jump (CMJ) test. PP was calculated using Duncan (PP_DUNCAN), Gomez-Bruton (PP_GOMEZ) and PE_CMJ formulas. A model with PE_CMJ as the predictor variable showed a higher predictive accuracy with PP_DUNCAN and PP_GOMEZ than CMJ height (R² = 0.99 and 0.97, respectively; ELPD_diff = 1037.0 and 646.7, respectively). Moreover, PE_CMJ showed a higher linear association with PP_DUNCAN and PP_GOMEZ across BMI groups than CMJ height (β_PECMJ range from 0.67 to 0.77 predicting PP_DUNCAN; and from 0.90 to 1.13 predicting PP_GOMEZ). Our results provide further support for proposing PE_CMJ as an index to measure PP of the lower limbs, taking into account the children's weight and not only the height of the jump. Therefore, we suggest the use of PE_CMJ in physical education classes as a valid method for estimating PP among children when laboratory methods are not feasible.