Is it better to do aerobic exercise before or after meals?

The answer is that there is no absolute good or bad answer. It all depends on your own physical condition, exercise goals and living habits. If you choose the right time that suits you, the effect will be ten times better than trying to copy someone else's "optimal solution".

To be honest, I struggled with this problem two years ago. At that time, I wanted to gain body fat to prepare for a half marathon. I followed the online tutorial and got up at 6 o'clock every day to run 10 kilometers on an empty stomach. I drank a cup of black coffee and went out. At that time, I did not have hypoglycemia and my body fat rate was around 18. I was a little hungry at the beginning, but the more I ran, the more I stretched. I lost 2 points of body fat in a month, and my pace increased by half a minute. At that time, everyone would say fasting aerobics yyds.

It wasn't until I took a little girl from my department who wanted to lose weight to run with me. She was usually a little anemic. She followed me for less than 3 kilometers without eating that morning. She squatted on the side of the road and stared at stars. I was scared to death. I gave her half an energy bar and waited for ten minutes. After that, I realized that there is no universal optimal solution.

In fact, there are two factions in the fitness circle that have been arguing for more than ten years. The core basis for the faction that supports fasting aerobics is that after a night's rest, the glycogen reserves are almost depleted. At this time, when doing moderate-intensity aerobics, the body cannot rely on enough glycogen for energy, and will provide energy. Before mobilizing fat to participate in energy supply, relevant research was published in the journal "Exercise Metabolism" in 2023, saying that at the same intensity, the fat oxidation rate of fasting aerobics is 15%-25% higher than that of one hour after a meal. This data is real and there is nothing wrong with it.

But the other side’s objections are reasonable: just because your fat supply ratio is high, it doesn’t mean you consume more. Moreover, if your glycogen reserves are insufficient and you have to do aerobics for a long time, your body will break down muscles to supply energy, which is not worth the loss. Not to mention people with stomach problems, hypoglycemia, and diabetes. If you do aerobics on an empty stomach, you may faint directly. The risk is too high.

If you have no underlying disease, your goal is to quickly remove fat, and the time of each exercise should be controlled within 45 minutes. The intensity is jogging, brisk walking, climbing stairs, jumping and low-intensity exercises. It is absolutely fine to do it before meals, and it is even more efficient. Now, if I am free in the morning, I will still drink a cup of light salt water and go downstairs for a 3-kilometer run, and then have breakfast when I come back. This will keep me energetic all day long.

But if you meet these conditions, I really recommend that you choose to do it after meals: either you have hypoglycemia, diabetes, or chronic gastritis, or your exercise plan today is long-distance running, cycling, or swimming for more than an hour, or you usually eat a small amount and have a weak constitution. Rest for 40 minutes to 1.5 hours after a meal before exercising, which is very stable. My mother has type 2 diabetes. I heard from my neighbor that walking on an empty stomach can lower blood sugar. After trying it twice, her blood sugar dropped to 3.2 and she was almost sent to the hospital. Later, she changed to taking an hour's rest after dinner every day to dance for 40 minutes in a square dance. Now her blood sugar is very stable, and she has even reduced the amount of antihypertensive medication.

And this "before and after meal" thing is not dead. If you are hungry before a meal and eat half a banana before exercising, that is not called after a meal, but something to eat. It does not affect the fat burning efficiency at all, and can also avoid hypoglycemia.； If you only have a light salad for lunch, then it’s perfectly fine to take a 20-minute break and walk downstairs for half an hour. Why wait 2 hours? I had a double-decker beef burger for lunch. I still felt sick to my stomach after taking a two-hour break to play ball. If I had eaten a small apple, I could have climbed the stairs in 15 minutes.

Really, many people struggle with this issue for several days. One moment they see others saying that to burn fat on an empty stomach, they should do it before meals. The next moment they see others saying that if it doesn’t hurt their stomach, they should do it after meals. They struggle over and over again and don’t do it even once a week. That’s a real loss. Just try it once every two days, and do it once before meals today. If you feel refreshed after doing it and don’t feel dizzy, nauseous, or have stomachache, then you can continue. ； If you feel extremely uncomfortable after doing it, then just eat and take a break before moving again. There are so many standard answers. The best time is the time that allows you to persevere.