Myzone estimates caloric expenditure using an equation that was developed in a study published in the Journal of Sports Sciences in 2005. In this study, participants performed steady-state exercise on a cycle ergometer or treadmill at multiple exercise intensities. Heart rate and VO2 were measured throughout.
The equation takes into consideration the user’s sex, weight, age, and heart rate—essentially, as much information about each user as is available.
Myzone does not track calories in the light gray zone, or below 50% of your MHR. The equation is most accurate at intensities above 50% and therefore calories will only be calculated above 50% (grey-red zones).
Myzone uses the following equations to estimate your caloric burn:
Men: C/min = (-55.0969 + 0.6309 x HR + 0.1988 x weight + 0.2017 x age) / 4.184
Women: C/min = (-20.4022 + 0.4472 x HR - 0.1263 x weight + 0.074 x age) / 4.184
NOTE: Is it important to note that calories measured are an estimate. Fitness trackers such as Fitbit, Apple Watch, and others all use different calorie equations, therefore calories might be different amongst all devices when compared to Myzone.