36 Hour Fast Calculator calculator can be used to determine the time needed to reach a target heart rate zone based on your age and resting heart rate.
Learn how to use the 36 Hour Fast Calculator calculator and its working principles
The calculator uses the following heart rate zones, which are based on percentages of your maximum heart rate (MHR):
This calculator provides an estimate based on simple formulas and should not replace professional medical advice. Always consult with a healthcare provider before starting a new exercise program, especially if you have any health concerns.