Attention all endurance athletes! Wanna get more from your cardio? Don’t give it 100%. Instead, give it about 20%

Athletes who repeatedly stress the same energy systems (by using as the common tempo and steady-state runs) generally experience excessive fatigue, hormonal imbalances, appetite loss, and tissue and bone damage.

This is why most elite endurance athletes use polarized training. In polarized training, only one-fifth of total workout time is spent at very high intensity. The other 80% of the time is spent at much lower intensities.

Studies have shown that polarized training leads to greater muscle adaptation as well as a greatly reduced risk of short term and chronic injury to the body than steady-state training.