West Chester University defensive end Travis Ford-Bey said playing in the heat make him feel, "real sluggish and [you] can't practice as hard."
It's a problem even professionals face. But head athletic trainer for the Eagles Rick Burkholder said this year at training camp things were better.
"We have cramps at every camp, but our numbers were way down this year," Burkholder said.
He attributes fewer heat problems to many tricks, including the slushy.
Burkholder said, "We used it extensively in training camp, in the 26 days we were there we had four slushie machines."
Sandy Fowkes Godek, Ph. D. of West Chester University said an Australian study has proven the slushie helped to lower runners body temperature before activity and that translated into better performance. She's now working to prove the same can be seen in football players. First the athletes swallowed a body core temperature sensor. It allows researchers to accurately monitor their body temperature throughout the process.
At several intervals 30 minutes before practice, half of the players drank a tea-flavored high-sodium sports drink from the refrigerator. It's kept at 10 degrees celcius (50 degrees Farenheit.) The other half drank the same solution, but in a slushie kept at negative 1 degree Celsius (30 degrees Farenheit.) The goal is to lower their body core temperature.
"With the idea that if you can lower it, even just a little bit, their ability to tolerate exercise in the heat is actually improved, " Godek said.
Preliminary results show the slushie caused three times as much cooling compared to the refrigerator drink.
As for the taste, Kyle O'Neill, who plays offensive line for West Chester said, "It's good, it's not bad, I know they have different flavors and the pomegrande is pretty good, especially for how much I had to drink."
Burkholder wants to see the finished scientific data from Godek, but even without it, he says players have noticed a difference so they'll continue to drink it.
"We're going to use it at the opening against Green Bay because it's supposed to be hot and rent a machine for Jacksonville because it'll be hot and see how it goes from there," he said.
Godek will be doing more studies on this and on the effects of sodium intake in athletes and how much is needed for different sports. She'll be doing her next study with the Philadelphia Flyers.