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5 Signs of Dehydration and How to Best Rehydrate

Hot weather is coming, and that means your athletes are at a higher risk of becoming dehydrated during practices and games. And even mild dehydration can impact athletic performance, as well as an athlete’s general health. Losing just two percent of an athlete’s bodyweight through sweat loss can change how an athlete is feeling and performing, whether they are sprinting at a track meet or participating in a day-long volleyball tournament.

Here, TrueSport Expert Stephanie Miezin, MS, RD, CSSD, is sharing what you need to know to help athletes stay safe on the field.

Signs of dehydration

1. Don’t count on the scale

As we mentioned, a loss of two percent of an athlete’s bodyweight due to sweat loss is a strong signal for dehydration. But in reality, that calculation is incredibly complicated. Miezin explains that you would need to weigh an athlete immediately prior to practice—accounting for clothing—then account for all fluid lost through using the bathroom as well as all fluid gained from sipping water or a sports drink, or even including food eaten. “It’s impractical for athletes, and for coaches,” she adds. You need a smart scale, a food scale, and a degree in mathematics to keep track of that two percent loss! That’s why most research that cites the two percent statistic is done in controlled lab conditions. So, in real life, how do you know if an athlete is becoming dehydrated?

2. Pay attention to subtle cues

Rising irritation levels, increased fatigue, dizziness, and trouble paying attention are all early warning signs that an athlete may be becoming dehydrated, says Miezin. The biggest sign is a drop in energy levels, which can sometimes be attributed to calorie deficiency rather than dehydration. The two are not mutually exclusive, of course, so if you’re noticing any of these signs in an athlete, stopping for a sports drink or water plus a snack break is a smart idea.

3. Look for physical indicators

Loss of coordination, nausea, and cramping are all indicators of dehydration, though they all have other causes as well. An athlete who seems to be losing coordination may be in the early stages of dehydration or even heat exhaustion, says Miezin. Unfortunately, loss of coordination and nausea can also both be brought on by a concussion, so it’s important to make sure that an athlete didn’t suffer from a hit to the head. Cramping may be another indicator of dehydration, though it’s not a guarantee. “We still don’t know exactly what causes cramping for athletes,” she says. “But because it may be caused by a fluid and electrolyte imbalance, making sure that an athlete who is cramping is rehydrating properly may be helpful.”

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Athlete Health TrueSport