Many of us get used to running as soon as we get to the playground or gym, and never stretch. And it's good to stretch after running, so it's a bad habit. If it is not done well, it will cause leg cramps and knee injuries. Not stretching after running will cause irreparable damage to the knee, and not stretching will not relieve muscle pain, but will make the legs thicker and thicker. Under normal circumstances, the legs will run thinner and thinner, so this is the influence of bad habits.
The second bad habit in running is uneven swing arm, which will cause physical pain after running for a long time. Another bad habit is running with your mobile phone. This will cause the weight imbalance on both sides of the body and make the body ache after running.
When running, you should choose to bring a leather bag instead of an arm bag. The arm bag is the same as running with a mobile phone, which will increase the weight on one side of the body and lead to imbalance. I know that professional athletes can even choose which foot to put the chip on.