I could get very scientific and write to you about mitochondria, electrolyte uptake, and homeostasis. But, as a wise person once told me, just because you “can” doesn’t mean you “should”. Besides which, I am a layman, not a physiologist so I don’t have the initials after my name to be taken seriously if I were to attempt to bore you with the science of hydration.
With that I will keep this simple and to the point. DRINK PLENTY OF NON ALCOHOLIC FLUID WHEN YOU TRAIN. Are we clear?
Listen, your body is roughly two-thirds water. When you exercise, your body releases a lot of that water to keep you cool both inside and out. If you don’t replace the fluid that your body releases in the form of sweat and vapor (as you exhale) very bad things will happen.
Several years ago, I had a brain fart and decided that I needed to do back to back 50k time trials on a hot day in July. I don’t generally take a water bottle with me when I time trial as it’s virtually impossible to dehydrate in an hour or so. Thus, I normally drink plenty of water and sport drinks ahead of time and I’m fine. That is to say, if I were only doing a single event. This particular day was very warm and humid and I was sweating prolifically during the first time trial. Before the second time trial, I rushed back to my car and drank a bottle of water that I had waiting for me but it wasn’t nearly enough. A sweating athlete should consume about 24 oz of liquid per hour of exercise. I was at about half that level and sure enough, about 20k into the second time trial, the dehydration cramps set in…badly. Every pedal stroke was greeted with cramps that shot from knee to pelvis along the groin of both legs. To make matters worse, I didn’t have a water bottle on board. Needless to say, it got worse from there. Eventually I was even cramping in my intercostals (muscles between the ribs). The time trial was a complete flail.
But – not only did my negligence of proper hydration ruin that time trial, the damage that I did to my body that day stayed with me throughout the remainder of the season. Whenever I needed to make a hard effort in a race or if I raced in temperatures over the mid 80’s my body would reject the notion. Shut down. I couldn’t get my heart rate elevated and my functional threshold was effectively about 30% diminished. I had to call an early end to the season to recover from what I had done to myself.
Your muscles and connective tissues are stimulated by electrical impulses. Without adequate electrolytes (calcium, potassium, magnesium) you will either function below optimum level (be slow) or malfunction all together (cramps). So, it’s a good idea to find a sport drink with electrolytes to keep you going. That said, too much of a good thing will give you some pretty nasty side effects. Remember – electrolytes are also used in laxatives. Over do it with the electrolytes and you’ll be facing some pretty severe stomach and gastrointestinal distress. Not pretty.
Personally, if I’m carrying two bottles on my bike during a race, one is a sport drink and the other is plain water. Some racers prefer to carry two bottles of diluted sport drink. You’ll need to find what works best for your body and stick with it. I’ve found that some brands of sport drink mix that my team mates swear by give me an upset stomach. You may experience this as well. Don’t believe all the hyperbole tossed out by the marketing departments about the efficacy of one brand over the others. The real benefit of sport drinks are that they contain WATER with some electrolytes and pretty much all of them do. If you’re well hydrated, you will race better regardless of the brand of sport drink you end up using.
I’ll conclude with a few bullet points
- Your body is roughly 2/3 water. Replace that fluid when you sweat
- Your muscles need adequate amounts of potassium, magnesium and calcium to properly react to the electrical impulses sent by your brain through your nervous system. You lose electrolytes when you sweat. Replace those electrolytes.
- Don’t over do it with the electrolytes – Most laxatives are simply “overdoses” of electrolytes
- 20-24 oz of fluid needs to be replaced per hour when you’re sweating. This of course will fluctuate with weather but even in the winter, you need to maintain proper hydration.
- Don’t wait until you’re thirsty to begin drinking.
- Get into the habit of maintaining proper hydration throughout the day, not just when you’re training or competing