What changes will happen to your body if you do aerobic exercise for 30 minutes a day?

Most people who insist on regular 30 minutes of moderate-intensity aerobic exercise every day for more than 3 months will first experience a significant improvement in their cardiorespiratory endurance. Later, they will also experience positive changes such as better metabolic status and more stable mood. However, there are also many people who have negative effects of joint damage and elevated cortisol due to problems with exercise methods and fitness. Not everyone can get the "positive buff".

I have been doing it intermittently for almost two years. At the beginning, I walked briskly around the community and ran intermittently after dinner every day. In the first month, the problem of having to rest for half a minute when climbing the fourth floor disappeared. My resting heart rate dropped from the usual 76 to early 60s. Even the pain that caused my aunt to take ibuprofen every time she came to visit has been relieved a lot. A while ago, I was having dinner with a friend I hadn't seen for a long time. She also said that I didn't look so "swollen". In fact, I hadn't lost a few pounds, but I had lost less subcutaneous fat, and my face and waist were tighter.

There are many counterexamples around us. Uncle Zhang downstairs followed the trend of morning jogging last year. He ran for 30 minutes on the cement road in the community at 6 o'clock every morning. He was still wearing old travel shoes from several years ago. Within three months of running, he was so painful that he had to have an MRI scan. He has an old disease of patellar chondromalacia, and hard running caused effusion in the joints. The doctor said that if he changed to a pair of cushioning shoes and walked on the plastic track, it would be better than running blindly. In order to meet the weight loss KPI, a girl in the same department set an alarm clock at 6 o'clock every day to get up and run for half an hour. She worked overtime until 11 or 12 o'clock every day and did not get enough sleep. After running for half a month, she not only gained three pounds in weight, but also had acne on her face. When she went to have an endocrine check, she found out that she was under a lot of stress. Running in the morning on an empty stomach made cortisol spike even higher, and she lost muscle and slowed down her metabolism.

I have also struggled with whether it is necessary to practice for 30 minutes at one time to be effective. Later, I checked the relevant research on domestic sports medicine. In fact, if I break it down into 10 minutes of moderate-intensity exercise in the morning, noon and evening, the cumulative cardiopulmonary improvement effect is less than 10% different from that of 30 minutes of exercise at once. For office workers who sit in the office every day, climbing to the 10th floor twice in the morning, walking around the office building for 10 minutes after lunch, and getting off the subway two stops before get off work is enough. Don’t have too high expectations for these 30 minutes. It’s unrealistic to expect you to lose ten pounds in a month. I gained two pounds in the first two months of running. Later I realized that the density of muscle is more than three times that of fat. The weight has not changed but the volume has shrunk. It is more practical to lose weight than to lose the number on the scale.

It’s interesting to say that I always thought aerobic was a “useless slow exercise”. But after I persisted, I discovered that it is more like a weekly small maintenance for the body. It does not require major repairs. It just unblocks the blocked metabolic pathways and relaxes the nerves that are always tense. Sometimes I am scolded at work, go out for a half-hour run, and when the sweat comes out, I am no longer so worried about any bad things. But if you have old joint injuries, or you have been so tired recently that you can't keep your eyes open, don't force yourself to participate in these 30 minutes of fun. If you practice hard, you will lose more than you gain. After all, exercise is supposed to add points to your life, not to complete KPIs.