Is the Polar M430 a Valid Tool for Estimating Maximal Oxygen Consumption in Adult Females?

Background: Previous research studies have found that heart rate monitors that predict maximal oxygen consumption (˙VO₂ max) are valid for males but overestimate ˙VO₂ max in females. Inaccurate self-reported physical activity (PA) levels may affect the validity of the prediction algorithm used to predict ˙VO₂ max. Purpose: To investigate the validity of the Polar M430 in predicting ˙VO₂ max among females with varying PA levels. Methods: Polar M430 was used to predict ˙VO₂ max (p ˙VO₂ max) for 43 healthy female study participants (26.9 ± 1.3 years), under three conditions: the participant’s self-selected PA category (sPA), one PA category below the sPA (sPA − 1), and one category above the sPA (sPA + 1). Indirect calorimetry was utilized to measure ˙VO₂ max (m ˙VO₂ max) via a modified Astrand treadmill protocol. Repeated-measures analyses of covariance using age and percentage of body fat as covariates were used to detect differences between groups. Bland–Altman plots were used to assess the precision of the measurement. Results: p ˙VO₂ max was significantly correlated with m ˙VO₂ max (r =.695, p <.001). The mean values for p ˙VO₂ max and m ˙VO₂ max were 44.58 ± 9.29 and 43.98 ± 8.76, respectively. No significant differences were found between m ˙VO₂ max, p ˙VO₂ max, sPA – 1, and sPA + 1 (p =.492). However, the Bland–Altman plots indicated a low level of precision with the estimate. Conclusions: The Polar M430 was a valid method to predict ˙VO₂ max across different sPA levels in females. Moreover, an under/overestimation in sPA had little effect on the predicted ˙VO₂ max.