Running economy and its correlation to performance and fitness variables in recreationally-trained distance runners

Abstract

Specific physiological attributes such as maximal oxygen consumption (VO2max) and running economy (RE) have been suggested to help predict long distance performance in endurance athletes. Despite this, investigations of RE have yielded conflicting results, particularly when comparing elite and recreational runners. The purpose of this study was to illustrate correlations between RE, expressed as submaximal oxygen consumption at a given speed, and time trial (TT) performance in addition to various fitness markers in endurance-trained individuals. Trained distance runners (n=21) performed a battery of tests over three sessions to provide measurements of RE at 2.68 m/s (RE2.68) and 4.25 m/s (RE4.25), TT performance, VO2max, velocity at ventilatory threshold (VVT), and body composition. Pearson-product moment correlations, defined as weak (r≥0.25), moderate (r≥0.45), and strong (r≥0.65), were calculated among all measures and significance was set at P<0.05. The findings suggested that faster TT performance was significantly (P<0.05) correlated to a higher VO2max (r=-0.86) and lower body fat percentage (BF%; r=0.78). However, TT performance displayed only a weak trend to RE4.25 (r=-0.40, P=0.07) and was not correlated to RE2.68 (r=0.15; P>0.05). Additionally, better RE4.25 (i.e. decreased submaximal oxygen consumption) was associated with a lower VO2max (r=0.66, P<0.05) and an increased BF% (r=-0.46, P<0.05). RE2.68 revealed no significant relationships with these measures. Comparable to their elite counterparts, higher aerobic capacity is strongly linked to performance in recreational distance runners, though in this cohort RE only weakly related to performance at the faster velocity. Finally, the inverse relationship between markers of overall fitness and RE suggests that enhanced RE may be an adaptive response to a limited physiological capacity in this population.