Advantages Of Doubles
Despite the latest fad a catchy magazine headline might try to sell you suggests, to run faster you have to run more. Running well at distances over 5K relies primarily on your aerobic endurance and development. Therefore, anything that a runner can do to boost his or her mileage will contribute to their overall aerobic development and progression.
Increased Training Benefits
The primary benefit of adding double runs to your weekly training routine is that running twice per day puts your body in a glycogen-depleted state, which enhances training adaptations, especially if you’re training for a marathon. Scientifically speaking, studies have shown that glycogen content, fat oxidation, and enzyme activity increase when training twice per day. In moderation, this means you’ll get fitter faster.
More Efficient Recovery
Running one 8-miler is definitely harder on the body than running two 4-milers. You don’t have to be a rocket scientist to know that training will be easier when you have the chance to rest and refuel in between runs. Furthermore, since the purpose of an easy run is to facilitate recovery, running twice per day increases the frequency at which you speed blood, oxygen and nutrients to the muscles.
Easier To Manage Long Training Days
For runners who are already waking up before dawn to get in their miles, adding more mileage to their morning routine might not be feasible. However, by incorporating double runs and turning your 8 or 10 miler into two runs — one in the morning and one in the evening — you can safely boost your overall mileage without being late for the morning commute.