First, you must stretch after running.
After running, there will be more and more leg muscles. If you don't relax your leg muscles in time, your legs will become thicker and stronger, which will not look good. Therefore, stretch the leg muscles after running, so that they can stretch. Specifically, you can choose lunge stretching, or stretch your legs on high places. Lunge stretch: the front legs are bent and the rear legs are straight, the front legs, thighs and calves are kept at 90 degrees, and the toes should not exceed the knees. Feel the muscles of the hind legs being slowly stretched. Stretch your legs alternately High leg lift: put one leg almost as high as your hip, which can be a railing, window sill, etc. Stand up straight with your other leg at 90 degrees to the ground. You can obviously feel the leg muscles stretching. Try to stick your abdomen to your thighs, and you will feel clearer.
The picture below shows leg press on the bar.
Second, avoid sedentary.
We have to work all day and sit on the sofa when we get home at night. So I sit or lie down most of the time every day. In this way, there is less movement in the legs, so fat will appear. I suggest you avoid sedentary, get up, take a walk and exercise.