What does aerobic exercise consume

During aerobic exercise, a mixture of glycogen and fat is consumed as energy. Only the energy supply proportions of the two vary at different stages of exercise, and a very small amount of protein is decomposed for energy throughout the process.

I have been going to the gym for almost 6 years, and this is the most common question asked by novices. Incidentally, they also struggle with "does not running for 30 minutes mean running in vain?" This statement has been controversial for a long time, and both sides have solid evidence. The last time I took a novice sister to do a fast walking and jogging interval, she kept holding on to the armrest for the first 15 minutes and panting. She said that she felt that she was not moving much and she must not have consumed fat. I looked at the sports watch she brought and found that the energy supply ratio of fat was 38%. In fact, from the first minute she started to move, fat was already participating in energy supply, but at that time, the proportion of glycogen stored in the muscles and liver was higher. When you run smoothly and your heart rate stabilizes in the aerobic range of 60%-70% of your maximum heart rate, after running for 20 minutes, part of the glycogen reserve is consumed, and the proportion of fat energy supply will slowly rise to more than 50%. If you continue to run for an hour, the proportion of fat energy supply can even reach 60%-70%.

In early years of exercise physiology research, it was indeed observed that when low-intensity aerobic exercise reaches about 30 minutes, the proportion of fat energy supply will exceed glycogen for the first time, so the saying "it takes 30 minutes to burn fat" was derived. When it was spread, it was simplified too extreme, and it became "30 minutes" "You've all been running in vain". In fact, both statements have their own applicable scenarios. For novices who have just started exercising, there is a high probability that they will not be able to stabilize their heart rate in the first 20 minutes, and they will stop and take a rest from time to time. Glycogen is consumed slowly, and the proportion of fat energy supply has not been increased. It is true that running for 30 minutes will be more efficient in brushing fat. In fact, our energy supply system is a bit like a hybrid car. When accelerating hard at the start, it relies on the motor (glycogen) to provide the power. When running and cruising at a constant speed, it mainly relies on the engine (fat). Both power sources are rotating throughout the process, but the proportion of the output is different in different scenarios. There is no sudden switching of power sources at a certain moment.

If you do long-distance aerobics for more than 90 minutes, such as cross-country running or riding a 100-kilometer bicycle, your body will also mobilize a small amount of protein to provide energy. Last week, I went to ride a 50-kilometer round-the-island road with my friends. After the ride, I was so tired that I couldn’t even lift mineral water. To put it bluntly, don’t worry too much about what to consume. If you want to burn fat, keep the intensity low to medium, and run as much as you can. If you really can’t spare the time, 20 minutes of effective aerobic exercise is better than lying down. The total calorie gap is the core of fat loss.