You've seen it before—the overzealous athlete chugging a gallon of water race morning. Is this necessary? Safe? Recommended? In the midst of summer and scorching temperatures, it's tempting to overdo it with fluids. But be careful. Overhydrating can lead to hyponatremia, when blood sodium levels become diluted. As a result, your body's water levels rise, and cells begin to swell. As you can guess, this isn't a good situation.
On the flipside—dehydration is incredibly dangerous as well. Dehydration occurs when you lose more fluids than you take in. Vigorous exercise, especially in hot or humid weather, expedites fluid loss through sweat. This condition can be mild to moderate, or severe. Mild/moderate symptoms include a dry mouth, tiredness, thirst, decreased urine output, dry skin, headache, constipation and dizziness. Severe dehydration takes a more drastic turn with warning signs like little to no urination, extreme thirst, sunken eyes, shriveled/dry skin, low blood pressure, rapid heartbeat, rapid breathing, fever and delirium.
Sodium, potassium, chloride, calcium, magnesium and phosphorus are all electrolytes lost via sweat; sodium is lost in the largest amounts. Electrolytes are in charge of maintaining water balance, helping your muscles contract/relax and assisting in nerve impulse transmissions. Electrolytes are vital to life and it is essential that they be maintained within their narrow operating windows. Most athletes supplement electrolytes during sport when they will be losing them via sweat.
Keep dehydration and over-hydration out of your race day by learning to take in just the right amount for your body. Here are some tips on how to hydrate just right.
* Hydration disclaimer: Everyone is different. Never try anything new on race day and always experiment in training to find what works best for you.
Track Urine Color
Urine should be a pale yellow color like lemonade—not clear, not apple juice colored. This is the most simple hydration assessment tool as you can use it anytime (well, besides those port-a-potties race day!).