When running, look straight ahead, shake your arms, make fists with both hands, you don’t need to clen hard, the front swing is slightly inward, and the back swing is slightly backward (I used to swing sideways and couldn’t run at all). Don’t lean forward too much, your knees don’t need to be raised high, and your toes land naturally. Never land on your heels. Breathing is about 3 steps as one exhalation and 3 steps as one inhalation. Keep it even. Breathing through the nose is not relying on the mouth, so do not run with your mouth open, it will be very tired.