How long should you do aerobic exercise for the best fat burning effect?

In fact, there is no one-size-fits-all optimal duration, but for the vast majority of ordinary athletes who just want to lose fat and have no need to prepare for competitions, 30 to 45 minutes of low-to-moderate intensity aerobics is the most cost-effective option for burning fat.

Last week, a junior who just got a fitness card chased me and asked me if I would lose weight faster the longer I run. The day before, he ran for 70 minutes, but his legs were so weak that he could walk on the wall. When he came home, he was so hungry that he ate two hamburgers and a portion of fried chicken. The next day when he went on the scale, he gained 20 pounds, and he was completely confused. Speaking of which, this misunderstanding is really common among many people. In the early years, the "20-minute threshold" was indeed popular in the fitness circle. It is said that glycogen is mainly consumed in the first 20 minutes of aerobic exercise. After 20 minutes, the proportion of fat energy supply will exceed that of glycogen. To burn fat, you have to survive the first 20 minutes. In recent years, new research has come out to refute it, saying that even if you break the 30 minutes into three 10-minute brisk walks or climb stairs, if you add up enough time in a day, the total fat burning amount will be about the same as if you practiced for 30 minutes at once, which is especially friendly to office workers who cannot squeeze out the whole time.

In fact, you can think of your body's energy reserves as your wallet. Glycogen is the change in your pocket, and fat is the fixed deposit locked in the cabinet. You must touch the change first when you go out to buy things. However, it does not mean that you must not move the change until the change is spent. It is just that the proportion of fat energy supply is low in the first 20 minutes, and it does not mean that it is not burned at all.

Depending on each person's situation, there is actually a lot of room for adjustment. If you are used to aerobic on an empty stomach and have less sugar in your stomach when you wake up in the morning, then practicing low-intensity aerobic for about 20 minutes is enough. You don’t have to hold on for a long time. If you faint on the treadmill, it will be worth the loss. If you have had enough rest after dinner before exercising and have sufficient glycogen reserves, you can extend the duration to about 40 minutes. If you have done 20 minutes of strength training before and used up part of the glycogen, then 25 minutes of aerobic training is enough, and the effect is better than 40 minutes of pure aerobics.

It is really not recommended that you extend the aerobic duration to more than 1 hour. If the time is too long, cortisol will spike. This thing will not only make the body subconsciously store fat to protect itself, but also consume muscles. If the muscle loses basal metabolism, it will decrease. In the future, you will be more likely to gain weight if you eat the same thing. It is purely picking up sesame seeds and throwing away watermelons.

In fact, you really don’t need to worry too much about the duration. If you don’t exercise at all, and you’re out of breath after just two steps, even if you only move for 15 minutes, it’s better than lying on the sofa. If you take your time, you can hold on, which is more effective than any precise duration.