Is there a relationship between running technique and running economy in well-trained, middle-distance athletes?

Abstract

The purpose of the present study was to investigate if a relationship between running technique and running economy exists in well-trained, middle-distance athletes. Four well-trained, middle-distance athletes performed a 15-minute exercise protocol on a treadmill, running at velocities 16.1, 17.6, 19.3 km.hr-1 for 5 minutes each without recovery. Oxygen uptake was measured and the subjects were video recorded throughout. Subjects’ ground contact time, stride frequency and stride length was calculated via the video recording. Immediately prior to the treadmill test, subjects performed a jumping test to attain a reactive strength index. Two values of running economy were calculated. The first was VO2 at 16.1 km.hr-1, and the second was relative change in VO2 with increasing running economy, thought to be more correlated to performance in well-trained middle-distance athletes. Following a Pearson’s product moment correlation analysis, a significant (P<0.01) correlation was only observed between ground contact time and running economy, expressed as the relative change in VO2 with increasing running velocity. Strong correlations were also observed between reactive strength index and running economy (r=-0.7), expressed as VO2 at 16.1 km.hr-1, and stride frequency and running economy (r=0.62), expressed as an increase in VO2 relative to increasing running velocity. It was concluded that running technique is more strongly correlated to running economy, when expressed as the relative change inwith increasing running velocity, predominantly through the technique parameter, ground contact time. It is thought that this is due to greater leg stiffness and a greater utilisation of elastic energy stored in the stretch shortening cycle. Foot-striking patterns may also have contributed. Future research should be directed towards methods of optimising ground contact time to increase running economy and middle-distance running performance.