Survival Tip #246
Listen to your Body
Your body will let you know when it is tired, weak, sick, or injured. It is important that you learn to listen to your body and recognize what it needs to recover. This doesn’t mean there won’t be times where you need to override what signals it is sending your brain, but you need to at least understand what is hindering you.
Justin Kassab 
Sound advice.
Only sometimes the body gets behind itself in reacting.
For instance, by the time you are feeling thirsty, you are already well on the way to dehydration.
Tired? Too late, now you are playing catch up and using internal resources faster than if you had just rested for a while.
Help your body to help you.
It’s a machine, a bio machine and like your car, you feed it, add water, maintain and REST IT to prevent failure.