If you do an aerobic exercise like running, you have to know how far you can go before risking injury. Exercise physiologists at Indiana University have formulated an easy way to know when you’ve had enough.
The study of runners shows that you have to ignore the advice of “no pain no gain” and stop when your fatigue starts to impair your form. The researchers discovered that pushing your limit through extreme tiredness produces excessive motion in your hips, knees and ankles.
“Our study showed that at the end of a normal run, when (runners) were getting tired, their mechanics were beginning to change,” says researcher Tracy Dierks. “When you notice fatigue, you’re most likely putting yourself at increased risk for injuries if you continue because it’s more difficult to control the motion ranges.”
Dierks warns that too much motion in your joints often leads to overuse injuries. The extra motion makes it harder for the muscles, tendons and ligaments to control the strain caused by running. Frequent overuse injuries in runners include patellofemoral (knee) pain syndrome, iliotibial band syndrome (pain at the side of the knee) and plantar fasciitis in the foot.