Body Composition (DXA) and Maximal Strength of Powerlifters: a Descriptive Quantitative and Longitudinal Study

International Journal of Exercise Science 16(4): 828-845, 2023. The purpose of this study was to present the relationships between maximal strength and body composition and to conduct yearly follow-ups presenting the chronic effects of maximal strength training on body composition. Thirty-four (age = 28.8 ± 8.7 yrs) classic powerlifters (M = 21; F = 13) completed at least one Dual-Energy X-Ray Absorptiometry (DXA) 43.97 ± 23.93 days after a sanctioned international powerlifting federation affiliate competition (Squat + Bench Press + Deadlift = Total (kg)). In addition, thirteen subjects (n = 13) completed at least one yearly follow up. Paired sample T-Tests and simple linear regressions were performed to determine significant effects on body composition and maximal strength measures. Prediction formulas were obtained as follows: Bone Mineral Content (BMC) (g) = 3.39 * Total (kg) + 1494.78 (r = 0.84; p \u3c 0.000; SEE = 348.05); Bone Mineral Density (BMD) (g/cm3) = 0.000390 * Total (kg) + 1.115 (r = 0.71; p \u3c 0.000; SEE = 0.062); Total (kg) = 10.84 * Lean Body Weight (LBW) (kg) – 154.89 (r = 0.90; p \u3c 0.000; SEE = 70.27); Total (kg) = 22.74 * Relative LBW (kg/m) – 306.66 (r = 0.92; p \u3c 0.000; SEE = 64.07). Significant differences were observed in BMD (+1.57 ± 1.55%; p = 0.018; ES = 0.22), between measures one and two (333.7 ± 36.3 days apart) as well as LBW (-2.95 ± 3.82%; p = 0.049; ES = 0.16), and Body Fat Percentage (+2.59%; p = 0.029; ES = 0.20) between measures two and three (336 ± 13.3 days apart). Thus, maximal strength can be used to predict BMC and BMD, while LBW can be used to predict maximal strength. As well, consistent powerlifting practice can increase BMD in adults