Estimation of maximal oxygen uptake using the heart rate ratio method in male recreational football players

Abstract

Maximal oxygen uptake (VO2max) is associated with cardiovascular and metabolic health in the general population. The heart rate (HR) ratio method (HRratio) is a valid, easy and accessible method for estimating VO2max in well-trained subjects. This study examined the validity of using the HRratio to estimate VO2max in recreational football players in the untrained and trained states. Sixty-six participants (age 39.3 ± 5.8 years) were tested pre-training and 28 after 12 weeks, for VO2max assessment, running on a treadmill alternating speed (1 km h−1) and inclination (1%) increments every 30 s until exhaustion. Maximal HR (HRmax) was assessed directly with a multiple approach and estimated with selected equations. Resting HR (HRrest) was measured in supine position, after 15 min of rest. The HRratio method considers the product of HRmax/HRrest ratio by a theoretical proportionality factor (15 ml kg−1 min−1, TPF) to estimate VO2max. This population-specific proportionality factor (SPF) was 14.6 ± 2.6 ml kg−1 min−1. In the untrained state (n = 66), participants’ actual VO2max (41.3 ± 6.2 ml kg−1 min−1) was moderately lower (~ 2 ml kg−1 min−1) than the estimated VO2max using the TPF. A nonsignificant difference (0.7 ml kg−1 min−1) was found when the VO2max was estimated using the SPF. When using HRmax equations and the TPF, a small nonsignificant difference (~ 1.5 ml kg−1 min−1) was reported between actual and estimated VO2max. In the trained state (n = 28), the estimated VO2max values were not significantly different from the actual VO2max (44.2 ± 5.2 ml kg−1 min−1), with large effect sizes when considering TPF and estimated HRmax. The results of this study provide evidence of the applicability of HRratio in estimating VO2max in male adult/middle-aged recreational football players.