A good cool down
Five minutes of gentle running is a good way to start a cool down.
Next, it is good to do some dynamic and static stretching exercises. However, do not do the stretching exercises too intensely or for too long. Training causes small but useful tears in your muscles, and it is not good to make them worse. After all, you want to use the stretching exercises to promote recovery from your training.
With dynamic stretching exercises, you loosen your muscles and joints and lengthen your muscles somewhat as you stretch. Examples of exercises you can do are lunges or the inchworm. For an inchworm, you start from an upright position. Next, you bend down and touch the floor with both hands. From that position, walk forward with your hands, keeping your legs straight. You will end up almost in the push-up position. When you are in that position, walk with your feet in small steps to your hands while keeping your hands on the floor. You will then be back in the starting position. Repeat this exercise several times.
Static stretching has been scientifically proven to reduce the risk of muscle and tendon injuries and overuse injuries. If you do them often enough, these exercises are also good for your flexibility. See the stretching exercises mentioned in the article for a good warm-up.
A rule of static stretching: never stretch to the point of feeling pain. Stretching should be felt, but the feeling should subside after five to ten seconds, after which you can increase the movement slightly in the next five to ten seconds.