Hydration and Performance

Our body weight is 50% water so it’s a pretty big deal if we get dehydrated, and it doesn’t take much for us to reach that point, especially since we are in the middle of Summer. So what happens when dehydrated?

Reduction in blood volume
Decreased blood flow, sweat rate & heat dissipation.
Increased core temperature, heart rate & degree of fatigue from faster muscle glycogen use.
Impairments in mental performance (skill and co-ordination)
Nausea
Muscle Cramps

And.. what does that mean??

A fluid decrease of 2.5% body weight can impair performance, and a drop of 5% can decrease work capacity by 30%... 30%! Also, your capacity for high intensity exercise (think sprints, Fran, or anything where you get exhausted after a few minutes) can be reduce by as much as 45%. That is huge!! (article)

Pretty much, it makes it a whole lot harder for your body to work in balance - blood is thicker, making it harder to pump though your system, therefore making it harder for the bood to carry essencial oxygen and nutrients. Not to mention harder for your body get rid of heat and anything else your body doesnt need as a bi-product of oxidation, such as carbon di-oxide.

Other side effects include:

Fat utilization is restricted (more glycogen)
Metabolism is slowed
Dry skin and bad breath
Food craving
Headaches

Moral of the Story: Drink plenty of water! Simple. Always make sure you rehydrate yourself during and after exercise, a simple way is to weigh yourself before & after exercise, and also before bed & first wake up, drink the difference in water.