The purpose of exercise and fitness is to maintain or improve the health level, emphasizing that exercisers must be self-disciplined and healthy. Therefore, in the process of fitness, all sports are carried out around this goal, which is systematic and scientific, but manual labor is completely different. Its purpose is to work and complete tasks. As long as you finish your work, no one will pay attention to the process and way of your labor, let alone emphasize that labor should be scientific.
Doing manual labor is to complete the task with repeated physical exercise, while exercise and fitness is to maintain the body. The former is consuming your body energy, and overwork will make you lack energy and accelerate aging. The latter is physical maintenance. Although it is a way to consume physical strength, this kind of consumption is beneficial, which can promote metabolism and muscle growth, make the body healthier and more energetic, thus delaying aging.
Manual labor is the mechanical reuse of a certain part of the body. In this process, the amount of muscle activity is unbalanced. When you do manual labor, you spend a lot of energy and time, and you don't consume much calories. The gym pursues holistic and systematic exercise, which can mobilize every muscle of the body and is more skillful, rather than repeating simple and meaningless actions.
Although doing manual labor and exercise are both activities, they are not the same concept. Therefore, sports activities are not fitness, let alone a substitute for fitness. Only by exercising for a long time can you have a strong body.