During a vigorous workout, the body may have lost important water- before any signs of thirst are given. Imagine, a body so dehydrated that it cannot even sweat and a dedicated athlete who is pushing on.

What's very misleading about dehydration is that there are no real early warning signs. Thirst is not always experienced. Fatigue can be mistaken for just being tired. Sweat loss is underestimated. For these reasons, being well-educated on the matter and not waiting for symptoms to set in is the best way to avoid dehydration. How does dehydration work? This condition places cardiovascular and thermoregulatory functions under severe stress- plasma decreases and therefore, so does cardiovascular function. This is because there is competition between muscle and skin for limited blood supply - which can quickly overwhelm the body's cardiovascular capacity to cope.

More seriously, this can also create the negative physiological circumstances that have tragically claimed the lives of athletes, which we sometimes see on high school and college fields during football camps. When the body cannot cope, fatigue can set in. If one continues the work-out after the body's warning signs- it can turn into leg cramps, heat exhaustion or even hart stroke.

That said, water is crucial to maintaining core body temperature and perhaps the best intervention for the aforementioned aliments. In fact, sometimes it's not even good enough to down a bottle of water after the exercise, and in fact, it is recommended that water be replenished throughout the workout, perhaps in 15-20 minute intervals. Just like the routine workout- a water-break routine should also be routine. Knowing ones own sweat rate will help tremendously, as replacing 100% of lost fluid is the healthiest thing to do.