Is it better to practice aerobic exercise on an empty stomach or after eating?

There is no standard answer that suits everyone. Whether to do it on an empty stomach or after a meal depends entirely on your fitness goals, physical condition, and the intensity of exercise you want to do that day. Just listen to those extreme statements on the Internet that "fasting aerobic fat burning is twice as good as after a meal" or "fasting exercise will definitely hurt your stomach and lose muscles". I have been running + strength training for almost 6 years. I have tried both modes no less than a hundred times. I have stepped on more pitfalls than I have run. Today I will explain it clearly to you.

First let’s talk about the fat burning issue that everyone is most concerned about. There are indeed studies that prove that glycogen reserves are low in a fasting state, and the proportion of fat energy supply during exercise will be 10%-20% higher than after a meal, but many people deliberately miss the second part: the total consumption is not much different. If you run for 30 minutes on an empty stomach and then run for 30 minutes after taking a break after a meal, the final calorie difference will be only a few dozen calories, which is far less practical than if you drink half a cup of milk tea less. When I was preparing for the half marathon last year, I tried running 5 kilometers in the morning on an empty stomach for two consecutive months. The rate of body fat loss was almost the same as the previous post-meal running stage. On the contrary, there were times when I got up so hard that I didn’t drink water or put anything on my back. When I ran too fast, my eyes became black. I squatted on the side of the road to slow down for 5 minutes. Finally, I turned to the breakfast stall and bought a hot bun before returning home.

Of course, this does not mean that fasting aerobics is completely useless. Its applicable scenarios are actually very clear. If you do not have problems such as hypoglycemia or chronic gastritis, your blood sugar is always stable, and you only plan to do 30-45 minutes of low-to-moderate intensity exercise that day - such as jogging, brisk walking, riding an elliptical machine, or doing a gentle yoga session, then doing it on an empty stomach is absolutely fine, and it can even save some time for digestion after eating. Now, if I wake up early on weekends and don't feel hungry, I drink half a cup of warm water, walk downstairs for 40 minutes, and then have breakfast when I come back. I feel refreshed all day long. But a word of caution, don’t follow what people say on the Internet and drink ice cream on an empty stomach. I have done this before to increase my energy. After running for 20 minutes, my stomach turned upside down and I almost vomited in the green belt. I still remember it to this day.

Let’s talk about what many people are afraid of: “gastroptosis will occur after eating”. This is really a misunderstanding. Just don’t rush out for a 5-kilometer run as soon as you finish grilling a bowl of beef noodles and burgers that are heavy with oil and spicy. Give your stomach some time to digest. If you eat a light meal such as oats, hard-boiled eggs, and a small portion of fruit, you can rest for 30 to 45 minutes before you can move. ； If you eat hard dishes that are difficult to digest, such as hot pot or barbecue, it is perfectly fine to rest for 1.5 to 2 hours. It will not cause gastroptosis at all.

Moreover, the advantages of postprandial aerobics are actually very obvious: hypoglycemia will not occur, and exercise performance is much better. If you want to run a long distance of more than 10 kilometers that day, do high-intensity Pamela jumps or boxing exercises, or even do mixed training with aerobic sessions, listen to me and be sure to eat something before moving. In order to burn more fat, my best friend went to a 40-minute boxing class on an empty stomach. Halfway through the jump, she held on to the pole and her face turned pale. The instructor stuffed half a banana into the gym to slow down. She originally wanted to burn more fat, but in the end she didn't even complete the normal amount of training, so the gain outweighed the gain.

In fact, both methods in the fitness circle have crowds of people. If you look at the bodybuilders preparing for the competition, many of them will regularly do fasting and low-intensity aerobics. The reason is very simple: their body fat has dropped to a very low level, and they need to adjust the proportion of fat for energy. Moreover, there are coaches watching the whole process, and they can keep up with supplements and protein intake. There is no need to worry about muscle loss or hypoglycemia. But we are just ordinary people who want to lose some fat and exercise. There is really no need to join in the fun. If you can't get up in the morning, take an hour's rest after dinner in the evening and walk downstairs for 40 minutes. If you insist on it for two months, you can still see your waistline shrink. There is no need to force yourself to get up early for that insignificant "fat-burning efficiency".

What I choose now depends entirely on my condition that day: if I’m not hungry when I wake up, and I don’t plan on doing any intensity that day, I’ll just go for it on an empty stomach.； If you are going to run a long distance that day, or have a strength class with aerobic finishing, you must eat a small piece of toast and an egg an hour in advance. This will keep your cadence more stable during the run, and you won't get hungry and get distracted halfway through the run.

You really don’t have to worry about this for too long. You can try both for a week and see which one you don’t feel uncomfortable doing and you won’t feel tired all day long after doing it. Then choose which one. There is no absolute standard answer to fitness. The one that allows you to stick to it is the best choice.