You've seen it before—the overzealous athlete chugging a gallon of water right before a race. Is this necessary? Safe? Recommended? It’s tempting to overdo it with fluids, but be careful. Overhydrating can lead to hyponatremia, which occurs 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.
Sodium, potassium, chloride, calcium, magnesium and phosphorus are all electrolytes lost via sweat, and sodium is lost in the largest amounts. Electrolytes are in charge of maintaining water balance, helping your muscles contract and relax and assisting in nerve impulse transmissions. Electrolytes are vital to life, and it is essential they be maintained within their narrow operating windows. Most athletes supplement electrolytes during sport when they expect to lose 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 simplest hydration assessment tool because you can use it anytime (besides in those porta potties on race day!).
Calculate Sweat Rate
Sweat rate is an incredibly individualized thing, which means fluid recommendations are given in a range:
- Make yours personal by finding an online sweat rate calculator.
- The average sweat rate per hour is 32 to 48 ounces.
- The average sodium losses per hour range from 500 to 1,500 mg.
- Set your fluid and electrolyte intake goals based on your findings.