Can aerobic exercise increase basal metabolism?

The answer is that there is no absolute "yes" or "no". The final effect depends entirely on how you arrange aerobic exercise and whether there is a matching diet and training combination. Simply saying that aerobic exercise can increase or decrease metabolism only touches half of the truth.

You must have seen two completely opposite real-life cases: someone runs and skips rope every day. Not only does he not lose weight after two months, but his scale increases after he eats a little more. He lost less than 100 pounds when he went to measure his basal metabolism.； There are also people who have been doing aerobics regularly for half a year, and their body fat has dropped by more than ten points, their basal metabolism has increased by several dozen, and they have not rebounded even though they eat more than before. Why is there such a big difference? The core depends on whether you can maintain or even increase your muscle mass when doing aerobics.

I once took care of a young girl who had just graduated. She was in a hurry to lose weight in order to take wedding photos. She ran 5 kilometers around the park every day after get off work and ate only a stick of corn for dinner. She lost 5 pounds in less than 20 days, but her complexion was sallow. She told me that she would gain two pounds even if she drank half a cup of milk tea. I took her to the gym and tested her with a physical tester. She found that her basal metabolism was more than 90 calories lower than the standard value for women of the same weight, and she lost 1.2 kilograms of muscle mass. To put it bluntly, when she ran, she not only burned fat, but also decomposed a lot of muscle. Muscle is a small boiler in your body that keeps burning 24 hours a day. Even if you lie down and check your phone, each kilogram of muscle can help you burn about 13 more calories every day. After dismantling several boilers, your metabolism will naturally drop.

But this is really not a problem with aerobic exercise. I also fell into the same trap when I was preparing for competitions in the past two years. At that time, in order to quickly burn off body fat, I ran for 40 minutes on an empty stomach every morning. I felt that strength training was taking up time and I stopped altogether. As a result, in the third week, I felt obviously lack of energy. Even my resting heart rate was 5 times lower than before. I asked a coach to measure my metabolism and I lost 120 calories. Later, I quickly added strength training back to my schedule, changed aerobic training to once every two days, and added 10 minutes of weight-bearing walking after each run. I increased my protein intake to 1.6 grams per kilogram of body weight in my diet, and then slowly adjusted my metabolism back.

For the little girl I just mentioned, I also planned the plan based on this idea. Before each run, I would do 20 minutes of dumbbell shoulder, hip and leg training. The running time would be shortened to 35 minutes. In addition to corn, I would add a palm-sized piece of fried or boiled chicken breast for dinner. Shrimp, after adjusting like this for a month and a half, she took another test and found that her muscle mass had increased by 0.8 kilograms, and her basal metabolism was 27 calories higher than when she first lost weight. Now that she occasionally eats hot pot milk tea, her scales will not increase as horribly as before.

In fact, academic circles have always had different conclusions on this issue. Earlier studies tracked a group of people who only did steady-state aerobics and no strength training, and found that their average basal metabolism did drop slightly after 3 months. The reason was the loss of muscle mass. This is also the core basis for many fitness bloggers to say "aerobic reduces metabolism", and it is not groundless.； But later follow-up studies on people who did aerobic and resistance training at the same time showed that the basal metabolism of this group of people not only did not decrease, but also increased slightly due to the decrease in body fat rate and the increase in muscle proportion. Especially for people with a large base and high body fat rate, the improvement effect will be more obvious.

There is really no need to treat aerobic as a metabolic killer, and don’t expect that running for half an hour a day can increase your metabolism by several hundred. It is just an ordinary way of consuming calories. Whether it can help your metabolism depends on whether you can match it. If you are really afraid of losing your metabolism, pump iron for 20 minutes before running, and eat two more bites of eggs and chicken, which is better than anything else.