Middle-aged people aged 30-40 are in their prime, and the unemployment rate is on the rise. They don't have much time to exercise, they are in good health, and they have no sense of urgency to exercise.
After the age of 40, people's physical fitness is getting worse and worse, and they begin to pay more attention to physical conditioning. They have stable jobs, more leisure time, perseverance and patience, and can keep exercising for a long time. At this time, the effect of fitness is the most obvious. After each exercise, they can feel a slight improvement in their physical fitness and increase their motivation for continuous fitness.
After the age of 65, people's physique has been unable to adapt to strenuous exercise. If we start fitness at this time, our qi and blood will drop, and the effect is not obvious. Even if you can persist, you will get twice the result with half the effort. Moreover, I only thought of fitness at this time. Generally speaking, our physical fitness is already very poor. Exercise can't solve all problems, but it will lead to physical problems due to excessive exercise.
In this way, 40-65 years old is the best age for exercise, but this does not mean that you have to wait until this age to exercise. Fitness is suitable for people of all ages. It is not too late to start at the age of 80, and it is not too early to start paying attention to exercise at the age of one or two. The body is your own, mainly regular maintenance, and always stay healthy. What we have to do is to keep the right amount of exercise at the right age. Even if you can't persist, how much you do will have some effect, and you won't wait until you are old to sigh for a lifetime.