Manzi, V, Impellizzeri, F, and Castagna, C. Aerobic fitness ecological validity in elite soccer players: a metabolic power approach. J Strength Cond Res 28(4): 914–919, 2014—The aim of this study was to examine the association between match metabolic power (MP) categories and aerobic fitness in elite-level male soccer players. Seventeen male professional soccer players were tested for V̇o2max, maximal aerobic speed (MAS), V̇o2 at ventilatory threshold (V̇o2VT and %V̇o2VT), and speed at a selected blood lactate concentration (4 mmol·L−1, VL4). Aerobic fitness tests were performed at the end of preseason and after 12 and 24 weeks during the championship. Aerobic fitness and MP variables were considered as mean of all seasonal testing and of 16 Championship home matches for all the calculations, respectively. Results showed that V̇o2max (from 0.55 to 0.68), MAS (from 0.52 to 0.72), V̇o2VT (from 0.72 to 0.83), %V̇o2maxVT (from 0.62 to 0.65), and VL4 (from 0.56 to 0.73) were significantly (p < 0.05 to 0.001) large to very large associated with MP variables. These results provide evidence to the ecological validity of aerobic fitness in male professional soccer. Strength and conditioning professionals should consider aerobic fitness in their training program when dealing with professional male soccer players. The MP method resulted an interesting approach for tracking external load in male professional soccer players.