After a hard workout, a runner’s muscles will have micro-tears from the forceful contractions which happen at fast speeds. These micro-tears cause muscle soreness, and make training the day after a hard workout difficult. The body heals these small micro-tears through the circulatory system, which delivers the oxygen and nutrients to the muscles that need repair. An easy recovery run increases blood flow to the muscles specific to running, helping to clear out waste products and deliver fresh oxygen and nutrients.
Why running recovery runs too fast is detrimental:
Your body does not have an infinite ability to heal itself and requires proper rest in between hard bouts. If you run too hard on an easy day, you create more muscle tears than you’re fixing, extending the amount of time you need to fully recover. This can cause you to run poorly on subsequent workouts because your muscles are still fatigued. Keeping your easy days truly easy will promote faster recovery, allowing you to be prepared for the next hard session and produce maximum results.