During hot-weather exercise, sweat rate increases to cool the body and prevent drastic changes in body temperature. Hydration is crucial for maintaining and improving performance in the heat. To maintain adequate hydration, try to replace 80%–100% of fluid lost through sweat during exercise, which can be achieved by drinking 4–8 ounces of fluid every 15–20 minutes.
Using strategies such as a cooling vest, ingestion of an ice slurry, or cold-water immersion (taking a cool or cold bath) have all been shown to improve exercise performance in the heat by as much as 5%, an effect due to a reduction in core body temperature. These strategies can be implemented before exercise (to start with a lower core body temperature) or during exercise (between sets) to intermittently cool down the body.[1]
Other strategies to improve aerobic exercise performance in the heat include heat acclimatization (7–14 days of exercise in the heat), wearing light-colored, moisture-wicking fabrics, and supplementing with electrolytes like sodium, potassium, and magnesium during exercise to maintain hydration status. Even proper sleep may help improve hot-weather aerobic exercise performance. Sleep deprivation can reduce sweat rate by almost 30% and elevate core body temperature.[1]