It takes 30 minutes before you start burning fat. Is it true?/You don't say. The body consumes fat all the time, including in a quiet state. Only with the intensity and time of exercise, the energy supply ratio of fat will change.

As shown in Figure 2:

When the exercise intensity reaches 75% or more of the maximum oxygen uptake, such as sprinting 100 meters, high-intensity iron stretching and other anaerobic sports, the energy is basically supplied by carbohydrates.

Exercise intensity is below 65% of the maximum oxygen uptake. Aerobic exercise such as walking and jogging will be powered by a mixture of carbohydrates and fat.

As shown in Figure 3:

Oxygen uptake is difficult to detect, so we usually use heart rate. If we exercise hard, our heart rate will be higher. The energy supply ratio of middle and low intensity (heart rate) fat is high.

Calculation method: fat burning heart rate =(220- age) ×60%~70%