We’ve all heard that it's important to drink at least eight 8-ounce glasses of water a day. But who drinks just water? Your clients are sipping lots of other liquids—including coffee, juice, smoothies, and even diet soda. But do they count as hydration? And what impacts do they have on fitness goals and performance?
“The important question to ask is: What else do they bring?” says Dominique Adair, MS, RD, a nutrition and fitness advisor who consults in New York and Los Angeles. “For starters, juice has carbohydrates, coffee has caffeine, and diet drinks have artificial sweeteners. The consumer needs to know what they’re really getting.”
Here, Adair and Kat Barefield, RDN, NASM-CPT, CES, PES, ACSM-HFS, a corporate registered dietitian nutritionist at dotFIT, share the reality of six common drinks.
- The Good: Water has no calories and is easily absorbed for basic hydration needs. It’s the ideal fluid for exercise lasting less than an hour.
- The Bad: For endurance exercise and intense activity lasting longer than an hour, plain water doesn’t provide an energy source to help maintain blood sugar levels. It also lacks electrolytes, which help with muscle function.
- Affect on Performance: For clients looking to lose weight, water should be the hydration method of choice. During workouts, set a timer for clients to drink 6 to 12 ounces of water every 15 to 20 minutes.
- Bottom Line: Drink up.
- The Good: It’s a convenient (and tasty) way to consume fruits and vegetables (and the associated nutrients) that might not be part of a client’s regular diet.
- The Bad: Some smoothies contain lots of sugar and calories. For example, a medium smoothie from a popular smoothie chain contains 400 calories—and 82 grams of sugar. To avoid surprises, check the nutrition label before purchasing or make your own at home so that you control the ingredients.
- Affect on Performance: The excessive calories in some smoothies may contribute to unwanted weight gain. To cut sugars, choose vegetable-based smoothies while on the go. If making your own, always measure the ingredients and keep things simple. For example: a cup of frozen pineapple blended with a half-cup each of Greek yogurt, milk, and OJ.
- Bottom Line: An occasional treat? You bet.
- The Good: These beverages can enhance recovery and muscle protein synthesis after exercise, says Barefield. A study at Baylor University in Waco, Texas, found that 20 grams of protein (a combination of whey, casein, and amino acids) taken within one hour of exercise gave participants greater strength and fat-free mass gains over a 10-week period than those who took a placebo.
- The Bad: Some protein drinks lack carbohydrates for glycogen replenishment, so they might not be optimal for recovery. Some, however, swing the other way: One brand contains 44 grams of sugar per serving.
- Affect on Performance: Research continues to show that recovery drinks with a combination of protein and carbs are effective at helping athletes recover and perform better, especially compared with carbohydrate-only recovery drinks.
- Bottom Line: Great after hard workouts, but watch the calories.
- The Good: Juice drinks can provide energy and nutrients, including vitamin C, folate, and even small amounts of fiber.
- The Bad: Most juices are high in calories. Your breakfast orange juice, even without added sugar, has 117 calories in a single cup. Also, the naturally occurring acids in some juice drinks can act as a dental corrosive.
- Affect on Performance: Minimal. Like many drinks, if consumed too close to physical activity, juices can cause stomach upset.
- Bottom Line: Moderation matters—try diluting juice drinks with water.
- The Good: Recent studies show that moderate intake isn’t dehydrating; caffeine can boost performance.
- The Bad: Coffee can cause gastrointestinal distress in some people.
- Affect on Performance: Studies show that a moderate amount of caffeine—equivalent to about 12 ounces of coffee—an hour before exercising can improve performance in endurance athletes. It may also reduce the perceived effort of exercise.
- Bottom Line: Good for a quick boost.
- The Good: Most diet sodas contain no calories, which can save more than 225 per medium drink.
- The Bad: Drinking sweet beverages—even zero-calorie soda—may confuse the body’s ability to manage calories based on taste. Research shows that daily consumption of diet soda may be linked to metabolic syndrome, a combination of ailments including high blood pressure and abdominal obesity.
- Affect on Performance: There are no known performance benefits (unless the drink has at least 200 mg of caffeine). The research is mixed regarding its effect on satiety and weight control.
- Bottom Line: Proceed with caution
Boost Your Skills: Hydration to Nutrition
As an NASM Certified Nutrition Coach (CNC), you can provide helpful advice to clients about hydration and nutrition. The course teaches trainers to explain how to balance caloric needs, activity, metabolism, and food choices. Trainers who take the course receive materials to pass along to clients, along with product discounts, menu planners, and online resources.
For more general nutrition tips, especially during these stressful times where we are looking to stay as healthy as we can, follow this link for our guide for staying healthy during COVID-19!