Studies have shown that keeping your heart rate in this zone is the best for burning away fat. Even during warm up when you are at 50 to 60%, you are burning more fat calories. It is when you exceed 70% and stay below 80% of your maximum heart rate that you start burning less fat calories and rely more on your heart and lungs to keep you going. Although, you will still burn about 50% as fat calories while exercising at this level such as running.
Performance trainers take it to the next level and exercise at 80 to 90% of their maximum heart rate. At this level you are burning on 15% fat calories. Exceeding this level is red lining your heart and only the healthiest of people can maintain exercise at this level.
There is a basic way to calculate what your ideal exercise range is. Using a simple formula by taking a base rate of 220 for men and 226 for women. Subtract your age to get your maximum heart rate or MHR. For instance a 45 year old man would take 220 - 45 and get a MHR of 176. This would be your maximum red line. So the warm up zone would be 50% to 60% of the MHR or 88 to 105 beats per minute. The ideal fat burning zone, 60% to 70% would be 105 to 123 beats per minute.
A more complex formula for calculating your health heart zone for exercise is by taking your resting heart rate into account by using the Karvonen formula. Which is basically the same as the simple formula, however you take your resting heart rate RHR and subtract it from the MHR to get your Heart Rate Reserve or HRR. You then calculate your target range, warm up would be 50% to 60% of your HHR, then add the RHR back into the number or in the example above using a 45 year old man, 118 to 129 beats per minute.
Here is a simple summary:
| Simple method | |||||||
| Base | 220 | for men, 226 for women | |||||
| - Age | 44 | ||||||
| MHR = | 176 | ||||||
| Training Range | Bpm | ||||||
| 60% = | 105 | ||||||
| 70% = | 123 | ||||||
| 80% = | 140 | ||||||
| 90% = | 158 | ||||||
| 100%= | 176 | ||||||
