Dehydration Facts and Athletic Performance


We discussed hydration facts and how amazing drinking water is for your body. Not soda, not redbull, not coffee, not sports drinks . ..water my friends . . good ole water.


So what about dehydration? – it nasty and does bad, bad things. Dehydration isn’t being in the desert and being thirsty, I mean sure it is that too but dehydration is sort of a sneaky thing that you aren’t even aware of it happening until things start to fall apart.


Exercise performance is impaired when an individual is dehydrated by as little as 2% of body weight. Losses in excess of 5% of body weight can decrease the capacity for work by about 30%

So you’ve been eating well, hitting the gym, trying to make gainz and oh wait . . you are not adequately hydrated and feel like crap while you work out and for some reason don’t perform how you thought you would be.

It’s crazy how much effort goes into athletic performance and when we say that it doesn’t mean the pro athlete performance – it’s any activity and at any level. If you aren’t hydrated you aren’t going to feel good which means you might want to avoid being active again. It’s not the activity though. The human body wants to move, it is meant to move but you need to aid it by doing the right thing.


The main reasons dehydration has an adverse effect on exercise performance can be:

  • Reduction in blood volume
  • Decreased skin blood flow
  • Decreased sweat rate
  • Decreased heat dissipation
  • Increased core temperature
  • Increased rate of muscle glycogen use


As dehydration increases, there is a gradual reduction in physical and mental performance. There is an increase in heart rate and body temperature, and an increased perception of how hard the exercise feels, especially when exercising in the heat.


Some guidelines

Aim to match your sweat rate with fluid intake as closely as possible.  

Ensure that you drink at a rate that is comfortable.  

Practice your competition fluid intake plan in training sessions. Write down and journal your workout sessions and water/food intake. If you felt good on a particular day follow that for water guidelines.

Get to know your sweat rate by weighing yourself before and after training sessions and competition.  

Water is an excellent fluid for low intensity and short duration sports.  

Sports drinks are ideally suited to high intensity ‘stop-go’ and endurance sports.