How you hydrate matters more than you might think. Fitness professionals are changing their water consumption habits based on scientific evidence—and you might want to follow their lead.
The Hydration Revolution in Fitness Circles
When it comes to staying hydrated during exercise, how you drink water can be just as important as how much you consume. Fitness trainers and exercise physiologists have been shifting away from certain hydration practices that research now suggests may be counterproductive or even potentially harmful.
“The way most people approach hydration during workouts is outdated,” says Dr. Stavros Kavouras, Director of the Hydration Science Lab at Arizona State University. “Many fitness professionals are now adopting evidence-based hydration strategies that optimize performance and recovery.”
The Problematic Practice: Gulping Ice-Cold Water During Intense Exercise
The hydration habit fitness professionals are increasingly avoiding? Drinking large amounts of ice-cold water during high-intensity workouts.
While it might seem refreshing to down an entire bottle of ice-cold water during an intense training session, research indicates this approach may be counterproductive for several reasons:
1. Digestive Discomfort and Performance Impact
According to a study published in the International Journal of Sport Nutrition and Exercise Metabolism, consuming large volumes of cold water during high-intensity exercise can lead to gastrointestinal distress in many individuals.
“When you gulp down large amounts of cold water during intense activity, your body diverts blood flow from working muscles to your digestive system,” explains sports nutritionist Nancy Clark, author of “Nancy Clark’s Sports Nutrition Guidebook.” “This can cause cramping, side stitches, and even nausea.”
2. Thermoregulation Interference
Your body generates significant heat during exercise—a natural and beneficial response. A 2019 study in the Journal of the International Society of Sports Nutrition found that consuming very cold water during intense exercise can temporarily interfere with the body’s natural thermoregulation processes.
“Some degree of core temperature increase during exercise is actually beneficial for optimal enzyme activity and metabolic function,” notes Dr. Douglas Casa, CEO of the Korey Stringer Institute at the University of Connecticut. “Excessive cooling through large volumes of ice-cold water might temporarily impair these adaptations.”
What Fitness Trainers Do Instead
Rather than abandoning hydration altogether, fitness professionals are adopting more strategic approaches:
Sipping Room Temperature Water
Many trainers now recommend sipping room temperature water in smaller amounts throughout workouts rather than gulping cold water.
“I advise my clients to take small, frequent sips of room temperature water during their workouts,” says certified strength and conditioning specialist Mike Boyle. “This approach minimizes GI discomfort while maintaining hydration levels.”
Strategic Pre-Hydration
Research published in the Journal of Athletic Training demonstrates that proper hydration before exercise significantly improves performance and reduces risk of heat-related illness.
“Starting your workout in a well-hydrated state is critical,” says Andy Galpin, PhD, Professor of Kinesiology at California State University, Fullerton. Many of my athletes focus on consistent hydration throughout the day rather than trying to catch up during the workout itself.
Electrolyte Consideration
Plain water isn’t always sufficient, especially for longer or more intense training sessions. A 2018 meta-analysis in the British Journal of Sports Medicine found that beverages containing sodium helped maintain fluid balance better than plain water during prolonged exercise.
“For sessions lasting over an hour, especially in hot conditions, including electrolytes becomes crucial,” says sports dietitian Tara Collingwood, MS, RDN. “This helps replace what’s lost through sweat and maintains proper fluid balance.”
Finding Your Personal Hydration Strategy
While fitness professionals are moving away from chugging ice-cold water during workouts, individual needs vary based on:
- Exercise intensity and duration
- Environmental conditions
- Personal sweat rate
- Individual digestive sensitivity
Dr. Stacy Sims, exercise physiologist and nutrition scientist, recommends a personalized approach: “Monitor your urine color—aim for pale yellow—and track your body weight before and after workouts to understand your specific hydration needs.”
The Bottom Line
The shift away from consuming large amounts of ice-cold water during intense workouts isn’t about drinking less—it’s about drinking smarter. By adopting a more measured approach to hydration—sipping rather than gulping, considering timing and temperature, and including electrolytes when appropriate—you can support optimal performance while minimizing digestive discomfort.
Next time you exercise, take a cue from fitness professionals: bring water, but be strategic about how and when you drink it.
