Marketing hype or scientific formula? We finally settle the issue of which works best for hydration – water or sports drink?
We've all experienced it at one time or another – in guard and a big dollop of sweat drops onto your face from up above! As your training partner apologizes profusely (or not) you continue to roll...
Hydration is a crucial part of exercising – particularly for those wearing additional clothing (e.g. Gi), training in a hot/humid environment (e.g. the gym) or those training for an extended period of time (most likely all of us!).
Fluid loss equivalent to just 1-2% of bodyweight can have a large impact. A sub-optimal state of hydration can lead to the following:
- Impaired mental function and concentration
- Impaired motor control
- A decrease in your ability to tolerate heat
- Impaired physical performance
- Slower gastric emptying
- Impaired recovery from training
Body temperature regulation, blood volume and heart rate are all affected by your hydration level and showing up to training or to an event dehydrated will render you at a disadvantage that you will not be able to make up.
In order to optimize (re)hydration, fluids must contain carbohydrate and electrolytes. A sports drink (such as Gatorade) that is 4-8% carbohydrate will facilitate gastric emptying and enhance fluid delivery. The presence of electrolytes also aids in fluid replenishment. Sweat composition varies from person to person, but, generally contains more sodium than potassium. As such, sodium should also be included (110-200mg per cup).
Drinking fluids that don't contain electrolytes can lead to increased urine output. That is, a further increase in fluid loss – leaving you even more dehydrated!
Consuming plain water can also blunt the thirst response, whereas citrus flavored beverages often increase fluid consumption.
Regardless of the type of training that you're doing, fluid consumption during and post training is absolutely essential for optimal performance and recovery.
So, how much do you need? The simplest method of assessing the amount of fluid you need to replace is to weigh yourself both before and after training (remember to remove any sweat-soaked training gear though). Each kilogram of body weight lost equates to 1 liter of fluid that needs to be replaced.
Therefore, sports drinks (such as Gatorade) that contain both carbohydrate and electrolytes (such as sodium) appear to be more effective at promoting hydration than just water alone.