Balance stress with rest.
Credit: Courtesy Ed Ayres

Learn how to adjust your regimen so you don't shortcut the recovery periods (days off, easy runs) that are needed to keep building endurance. That way, we can avoid those times when, as he says, the training effect begins to reverse and instead causes a stale physical feeling, performance slumps, and even illness and injury. Ayers points out that the trick to finding balance is an essentially personal proposition that has to be learned over time. For instance, for many athletes, speed work will require more recovery time between sessions than slower base building.

Life's varied stresses, from work to family and beyond, should also be considered when calculating the actual stress of running. If you're dealing with a lot off the trail, you might not be able to train as hard during those days. For instance, for Ayres, who often runs on the Pacific Crest Trail and lives in a house surrounded by the Angeles National Forest north of L.A., recovery periods might include clearing brush or building hardscape – enjoyable time off for the active outdoors enthusiast.