
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

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.”
4. Early dehydration doesn’t have obvious physical manifestations
“I remember having a coach who would take me out of games almost immediately when it was hot out, because my face would get very red, very easily,” Miezin recalls. A red face isn’t an indicator of dehydration or even heat exhaustion, though. Some people are just naturally more prone to flushing in higher temperatures. Some athletes are also heavier sweaters than others, and while it might look worrisome, it’s perfectly natural. For the heavier sweaters, do prioritize sports drinks or water with added electrolytes, as those athletes are losing more electrolytes and fluids at a higher rate than less sweaty athletes.
5. Educate your athletes

How to Rehydrate
1. Dehydration can happen even in short practices
If practices or games run over an hour, make sure you’re allowing athletes time for an electrolyte-infused water and/or snack break. If a session is particularly intense, especially in hot weather, you may need to break more often. While most short practices don’t require an athlete to take in extra water or calories, if the athlete is starting practice mildly dehydrated, even a 45-minute session can dehydrate them. As temperatures rise, recommend that athletes show up to practice with sports drink or water that has electrolytes or a pinch of sea salt added. And never disallow an athlete from taking a break to hit the water fountain if they ask!
2. Rehydrate with electrolytes and water

3. Don’t gulp gallons of water
When rehydrating an athlete, try to focus on slow and steady sipping. Sipping allows for better absorption of water rather than chugging. Drinking too much, too fast can have other potentially harmful effects other than needing to take more bathroom breaks. “It’s generally not ideal to encourage athletes to start chugging plain water,” says Miezin. “Water without electrolytes can lead to hyponatremia when consumed in large quantities, which is when the body’s sodium levels become dangerously low.” Unfortunately, hyponatremia can be deadly for young athletes, which makes following rehydration procedures even more critical. Water alone won’t rehydrate your athlete: A balance of electrolytes and water is necessary.
4. Take a break

5. Dehydration is a year-round issue
In the summer, athletes are more likely to become dehydrated due to heat and humidity, but it can happen anytime during the year. Indoor practices are often pretty warm and busy lifestyles can lead to dehydration even on mild days. So, keep an eye out for these symptoms all the time, not just when summer hits.
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Takeaway
Dehydration symptoms are hard to see, so pay close attention for signs like a loss of coordination, increased irritability, and fading energy. If you suspect an athlete is becoming dehydrated, ensure that they pause and sip a sports drink, as well as allow their bodies to cool down.