Heart rate cost of running in track estimates velocity associated with maximal oxygen uptake.

ABSTRACT

BACKGROUND: Running velocity associated with VO2max (vVO2max) is a parameter widely used for exercise prescription and is related to endurance performance. However, the vVO2max determination usually requires a maximal effort test and equipped laboratory for expired gas analysis, what make difficulty its assessment. OBJECTIVE: We aimed to test the validity of a simple method of vVO2max prediction through the heart rate cost of running (HRC) in a submaximal 6-min running test, both in treadmill and in a 400-meter track. METHODS: Male recreational runners (n = 16; 30.3 ±â€¯8.0 years; VO2max of 46.2 ±â€¯3.2 ml·kg-1·min-1) randomly underwent an incremental test in treadmill with gas analysis, and a 3000-m time trial in a track, to determine vVO2max. Before every maximal test, participants also performed a submaximal 6-min running (~85% HRmax), both in the treadmill and in a track, to assess HRC (bpm-1m·min-1) by dividing the submaximal running velocity by its respective HR. The vVO2max (km·h-1) was predicted by dividing the HRmax (bpm)/HRC (bpm-1m·min-1). RESULTS: No differences were verified (p > .05) among vVO2max determined both in the treadmill (13.8 ±â€¯0.9 km·h-1) and track (13.6 ±â€¯0.9 km·h-1) to those predicted by the HRC method both in treadmill (13.5 ±â€¯0.8 km·h-1) and track (13.6 ±â€¯1.0 km·h-1). The vVO2max measured directly with expired gas analysis was highly correlated with vVO2max estimated through HRC in treadmill and track (p < .05). Additionally, the intraclass correlation coefficient (ICC) and Bland-Altman technique revealed good agreement and reliability classified with substantial agreement [ICC = 0.673 (95% CI 0.064-0.886; p = .019)] and almost perfect agreement [ICC = 0.870 (95% CI 0.628-0.955 p = .0001)] between methods to identify vVO2max, respectively. CONCLUSION: A submaximal 6-min exercise test protocol to assess HRC of running was considered valid to estimate vVO2max of recreational runners both in treadmill and outdoor track.