Is body cell mass a predictive index of performance in male recreational long-distance runners?

Body composition could be useful for evaluating specific adaptations to different physical training regimens. The objective of this study was to verify the impact of body cell mass (BCM), fat-free mass (FFM) and fat mass (FM), assessed by bioelectrical impedance, in time trials in male recreational long-distance runners (42.195 km). The study group comprised 14 healthy, well-trained male recreational long-distance runners (age 45.9 ± 7.2 years), all of whom were participants in the Rome marathon. Anthropometric and bioelectrical impedance measurements were obtained to determine body composition. During the week before the marathon, maximal oxygen uptake was determined using an incremental running test on a motorized treadmill. BCM was significantly and inversely correlated with the marathon time of the runners. FFM was also correlated with marathon time, but to a lower level than BCM, and FM was not correlated. In addition, Resting metabolic rate was inversely correlated with marathon time (r = −0.69) and highly correlated with BCM (r = 0.77). In conclusion, BCM measured by bioelectrical impedance is a strong predictor of muscle efficiency.