Probably that is the most frequent question of running athletes or marathoners.
Running in old or torn shoes is one of the main causes of injuries. Generally, running shoes with torn and worn padding are less shock proof, and less durability.
Using worn out running shoes continuously increases the stress and shock on your feet and legs that can be a cause of joint injuries.
The easiest measure you can do to prevent future injuries is to purchase a new pair of running shoes as soon as your old pair are worn out.
But how can you determine if your old pair needs replacing?