Matthew Kadey
Published July 9, 2026 06:00AM
You’ve likely noticed that your summer workouts and races are increasingly taking place in what is tantamount to an outdoor sauna. But training in the heat presents several challenges that can sour performance and fitness gains. Exercising in hot conditions not only increases feelings of discomfort; it alters how the body manages fluids, regulates core temperature, and tolerates fueling. We know that heat-induced hyperthermia, abnormally high body temperature, can limit endurance performance
While heat acclimation is perhaps the best strategy to improve performance in a hot environment, there is one hydration strategy you can use to help lessen the impact the outdoor sizzle has on how fast and long you can go. And that game plan is to harness the powers of the mighty slushy
Yes, the same kind of drink you loved getting from the 7-Eleven when you were a kid might be the secret weapon to still performing like a champ when the blazing sun won’t let up. Here’s how the frost-bitten drink and can help athletes beat the heat
What the science says about slushies and exercise performance
A2025 study published in the journal Medicine & Science in Sports & Exercise provided healthy male subjects with the same amounts of either an ice slurry or a warmer drink (7.5 grams per kilogram body weight) 30 minutes before completing a fairly intense bout of cycling in the heat (95 degrees F ambient temperature)
The scientists discovered that esophageal, rectal, and gastrointestinal temperatures were lower in study participants when they consumed the icy drink. Further, hyperventilation (rapid, deep breathing) was lower, and brain blood flow was higher in the frosty drink trial. As a general trend, the cyclists were able to ride for longer before exhaustion set in when they took in the ice-cold drink before hopping on the saddle
Other research suggests that consuming relatively low amounts (450 grams) of ice slurry during a short break from high-intensity intermittent exercises in the heat can reduce body temperature and improve peak power, thereby providing a hydration strategy to improve endurance exercise performance in steamy conditions
There is evidence that ice slurry ingestion during break times appears to be an effective cooling strategy to lower the rise of core body temperature in the second half of exercise, and results in improved repeated-sprint exercise capacity in the heat
As a recovery aid, a study in the Journal of Thermal Biology showed that consuming an icy drink after a bout of endurance exercise in hot conditions can encourage better core and skin temperature recovery
So it appears that taking in a slushie-style drink before, during, and after red-hot exercise, prepared from plain ice, crushed ice, or sports drink, can havea beneficial effecton thermoregulation and exercise performance
Why slushies are so rad for hot-weather workouts
Perhaps the lower body temperature helps reduce perceived exertion. Feeling cooler makes the exercise seem easier so you can perform more optimally. Also, voluntary intake of cold fluid is often greater than the unappetizing warm sugary fluid in your bottle, resulting in better maintenance of hydration status
If your deep freeze drink contains some simple carbohydrates from a sports drink or fruit juice, then this can provide an extra in the drink encourages water retention and can help offset sodium losses that occur when sweating big-time
But we don’t yet know just how much of an endurance boost you can expect, and if colder drinks can significantly reduce the risk for heat illnesses that can occur when you are working out in sauna-like conditions. Also, some people may experience adverse GI effects in response to drinking icy drinks before and during exercise that could squash out any possible performance benefit. So it’s important to test out this drinking protocol during training to gauge tolerance
A pre-workout slushy protocol
There are a couple of protocols you can try to make frosty drinks a part of your hot weather fueling strategy
About 30 minutes before heading out for a workout in the heat, try drinking a couple of cups of an icy drink, such as the homemade slushies below. (To limit the brain freeze, don’t chug these too fast.)
On top of this, you can try consuming frosty drinks during training and competition in the heat. This could mean having these drinks available to you at aid stations if you are allowed to stash them in insulated containers at these locations. It’s also possible to travel with them on the bike if you want to bring along an insulated water bottle such as Bivo that will keep cold fluids cold
Recipe: Homemade pre-workout slushies to keep you cool
Mango slushy
With just a quick spin in the blender, this thirst-quenching slushy is bursting with tropical flavor and is a great way to hydrate and cool down before going to battle with the heat. Much better than what spurts out of the gas station slushie machine
- 1 cup water or coconut water
- 1/2 cup frozen mango cubes
- 2 teaspoons fresh lime juice
- 1 teaspoon honey
- 1/8 teaspoon salt
Combine all the ingredients in a blender container and process into a slushy consistency. Don’t overprocess into a completely smooth liquid
Sporty slushy
This is a way to make your sports drink work harder for you. If you want to use this during your exercise session, be sure to pour it into an insulated bottle. Most sports drinks contain some sodium, so no need to add additional salt. However, if you will be sweating buckets because it’s just so hot outside, then you could stand to benefit by blending in a pinch of salt
- 1 1/2 cups sports drink
- 1 cup ice cubes
Combine the ingredients in a blender container and process into a slushy consistency
