REST

There is a difference between not training and resting and one should not be mistaken for the other. A day off due to heavy travel or any other reason doesn't constitute a choice to rest (unless you planned it) and depending on the activity may not be in your body's best interest to count it as a rest day. Spending most of the day on your feet or sitting on a commercial airplane that must have been manufactured for dwarfs doesn't expedite recovery from the previous days damage. Sometimes taking one day off is not enough, especially considering the amount of gross and cumulative damage we incur. If enthusiasm wanes and physical pain persists beyond its usual stay then it may be prudent to fully recover before taking another step forward. We get mentally stronger while training but physically stronger while resting. We rest hard in order to train harder.