Validity of the Polar M430 Among Females of Varying Fitness Levels, Body Fat Percentage, and Reported Physical Activity

Introduction: The Polar M430 is a heart rate monitor that uses a non-exercise prediction method to predict one’s V̇O2max. Research has revealed that this method will overestimate predicted V̇O2max among females. Studies have investigated the validity of this method, however, these studies have not taken into account how physical activity (PA) levels, body fat percentage, or measured V̇O2max could affect the prediction value. Purpose: The purpose of this study was to investigate the validity of the Polar M430 in predicting V̇O2max amongst females of varying PA levels, body fat percentages, and fitness levels. Methods: Forty-eight female participants were recruited for this study. After entering age, height, weight, gender, and self-reported PA, into the Polar M430 the Polar Fitness Test was started to obtain their predicted V̇O2max (pV̇O2max). The test was performed three times: at the participant’s self-selected PA category (sV̇O2max), and one PA category below the sV̇O2max (sV̇O2max -1), and one category above the sV̇O2max (sV̇O2max+1). Measured V̇O2max (aV̇O2max) was assessed via indirect calorimetry using a modified Astrand treadmill protocol. To compare fitness level and body fat percentage, data for those values were split into quartiles and a repeated measures (RM) ANOVA was used to detect differences between groups. Results: There were no significant differences between mean pV̇O2max and aV̇O2max values (p > 0.05). pV̇O2max was significantly correlated with aV̇O2max (r = .697, p < .0001). There was no significant difference between aV̇O2max and pV̇O2max at sV̇O2max - 1 and sV̇O2max+1 (p> 0.05). There were also no significant differences between quartiles groups for any of the secondary variables (p > 0.05). Conclusion: Among females, using the Polar M430 is a valid method to predict V̇O2max. These results were consistent across different fitness levels, body fat percentages, and PA categories