Muscle aches are caused by excessive exercise, which leads to lactic acid not being absorbed in time. Or because I don't usually exercise this muscle. Just like people who don't usually run, their thighs will ache the next day after running, and it will hurt if they move a little. However, if you want to grow muscles, you must stick to it, just don't rush for success, step by step, and excessive exercise will strain your muscles. Fat people don't eat it all at once. If the muscle is very painful, you can gently pinch the muscle with your other hand at the painful place, or apply hot compress and gently rub it to let the lactic acid in the muscle be absorbed as soon as possible, so that it will not hurt. Don't worry, this is a normal muscle growth process.