Use of a heart rate‐to‐ground contact time index to monitor and predict middle‐distance running

The purpose of the present study was to determine if field‐based variables associated with cardiovascular and neuromuscular stress could be used to accurately monitor and predict middle‐distance running. Eleven middle‐distance runners (age 21.3±1.6 years) completed three trials of steady‐state running at 11, 13, and 15 km · h –1 , and test performance was compared with competitive performance (personal best times converted to standardized Mericer scores). Oxygen uptake, heart rate (HR), and stride characteristics (ground contact time [Ct], flight time, step length, and step frequency) were monitored during treadmill running with the ratio of HR:1/Ct calculated. Heart rate and stride characteristics were significantly altered (all P <0.05) with increased running speed, while the HR:1/Ct index was unchanged. Stride characteristics, heart rate, and the HR:1/Ct index were reliable measures with no mean bias and low levels of random variation. The HR:1/Ct index was strongly related to competitive performance ( r =–0.80 to 0.88, P <0.01). This was primarily attributed to the association between heart rate and Mercier scores ( r =–0.81 to 0.87, P <0.01), whereas ground contact time was only moderately related to competitive performance at the fastest running speed ( r =–0.60, P <0.05). Simple measures associated with cardiovascular and neuromuscular stress can be reliably monitored in middle‐distance runners. A HR:1/Ct index provides a stable measure at any given submaximal running speed and may provide a useful tool for monitoring and predicting middle‐distance running.