It is a learned training mechanism...
Fitness has 4 legs; proper training, good nutrition, a fit mindset, and rest/recovery/sleep.
When in balance the sky is the limit.
Often time sleep/rest/recovery takes a back seat.
Signs of insufficient sleep/rest:
- poor energy
- decreased exercise tolerance/poor workout performance
- poor motivation
- feeling sleepy
- persistant soreness
Proper rest produces peak performance