Abstract
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 (R(2) = 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.