Contributions of body-composition characteristics to critical power and anaerobic work capacity

Critical power (CP) and anaerobic work capacity (AWC) from the CP test represent distinct parameters related to metabolic characteristics of the whole body and active muscle tissue, respectively. Purpose: To examine the contribution of whole-body composition characteristics and local lean mass to further elucidate the differences in metabolic characteristics between CP and AWC as they relate to whole body and local factors. Methods: Fifteen anaerobically trained men were assessed for whole-body (% body fat and mineral-free lean mass [LBM]) and local mineral-free thigh lean mass (TLM) composition characteristics. CP and AWC were determined from the 3-min all-out CP test. Statistical analyses included Pearson product–moment correlations and stepwise multiple-regression analyses (P ? .05). Results: Only LBM contributed significantly to the prediction of CP (CP = 2.3 [LBM] + 56.7 [r² = .346, standard error of the estimate (SEE) = 31.4 W, P = .021]), and only TLM to AWC (AWC = 0.8 [TLM] + 3.7 [r² = .479, SEE = 2.2 kJ, P = .004]). Conclusions: The aerobic component (CP) of the CP test was most closely related to LBM, and the anaerobic component (AWC) was more closely related to the TLM. These findings support the theory that CP and AWC are separate measures of whole-body metabolic capabilities and the energy stores in the activated local muscle groups, respectively. Thus, training programs to improve CP and AWC should be designed to include resistance-training exercises to increase whole-body LBM and local TLM.