Sports Drinks

Commercially available sports drinks such as Gatorade and Powerade contain carbohydrates, electrolytes, and other nutrients. These products claim to improve rehydration and provide energy to keep workouts going longer. This presumably leads to increased strength, endurance, and overall performance gains.

Given these claims, do we really need to consume more sugar in order to increase performance? Do these products improve performance more than sugar free beverages or even water?

Water, Electrolytes, and Exercise

Water is arguably the most important substance in the body. It transports nutrients, eliminates waste, maintains blood pressure, lubricates joints, and regulates temperature1.

Electrolytes are minerals with an electric charge. They balance the amount of water in the body, move nutrients in and waste out of cells, and have important roles in the way nerves, muscles, and the heart work. Sodium, calcium, potassium, chlorine, phosphate, and magnesium are all examples of electrolytes2.

Exercise increases temperature which the body deals with through sweating. Sweat is composed mainly of water and electrolytes. Excessive sweating leads to substantial water and electrolyte losses, decreasing performance. During prolonged exercise, replenishing water and electrolytes prevents heat related injuries and potentially, increases performance.

What does research say about sports drinks?

Study 1: Anaerobic performance when rehydrating with water or commercially available sports drinks during prolonged exercise in the heat3

The first study looked at the effects four commercially available drinks had on leg power and force during prolonged cycling in the heat. Seven cyclists pedaled for two hours in a hot, dry environment. Subjects either drank mineral water (San Benedetto), a 6% carbohydrate-electrolyte solution (Gatorade), an 8% carbohydrate-electrolyte solution (Powerade), an 8% carbohydrate-electrolyte solution with lower sodium (Aquarius), or did not consume any fluid.

Results showed the commercially available drinks, specifically Gatorade and Powerade, did better at maintaining performance in the heat than other options. Gatorade and Powerade preserved contraction force better than San Benedetto, Aquarius, and no fluid.

Maximum cycling power was similar in all of the trials. The final body temperature reading was higher in the no fluid trial than any of the beverages. Researchers concluded that compared to no hydration, commercially available sports drinks prolonged exercise and maintained leg force better than water.

Study 2: Carbohydrate-Supplement Form and Exercise Performance4

The next study examined the effects of various forms of carbohydrates on performance. In four separate sessions, participants cycled for 80 minutes followed by a 10-km time trial. Participants consumed jelly beans, sports drinks, gel, and, water in each of the  four separate sessions. Subjects were given 0.6 grams of carbohydrate per kg per hour (0.27 grams per pound per hour).

Results showed blood glucose concentrations were similar for all carbs. Blood glucose concentrations were higher in the carb sessions than the water session. The 10-km time trial were significantly faster when subjects used a carb supplement compared to only consuming water.

Study 3: Superior Endurance Performance with Ingestion of Multiple Transportable Carbohydrates5

This study investigated the effects of various types of carbohydrate drinks on endurance performance. Eight cyclists consumed either water, a glucose only drink, or a combined glucose and fructose beverage. The participants who drank one of the carbohydrate beverages were given 1.8 grams of carbohydrates per minute.

Subjects completed 120 minutes of cycling followed by timed trials in which they completed a set amount of work as quickly as possible. The time trial of those drinking the glucose/fructose was 8% faster the the glucose only group. The glucose/fructose combo group was 19% faster than the water only group.

Study 4: Supplementary effect of carbohydrate-electrolyte drink on sports performance, lactate removal & cardiovascular response of athletes6

The final study looked at the effects of carbohydrate supplementation on performance and recovery. This study included 10 participants. Subjects went through two phases. The first phase contained no carbohydrate drink. During the second phase, subjects drank a carbohydrate drink during exercise and during recovery.

Results showed significant improvements in total endurance time, heart rate responses, and blood lactate levels  in the second phase. Measures of recovery also improved during carbohydrate supplementation. Researchers concluded carbohydrate-electrolyte drinks increased endurance performance and enhanced the recovery process.

The Bottom Line: Are sports drinks necessary?

The research is clear in concluding carbohydrate sports drinks improve performance in both strength and endurance activities. The improvement is seen when compared to no hydration and even water only intake. There is one major caveat: the exercise intensity of these studies are much higher than average individuals typically utilize. Many of these studies involved hours of cycling followed by more exercise. Lower intensity workouts may not benefit as much from a sports drink.

The American College of Sports Medicine recommends drinking 3-8 fluid ounces of water every 15-20 minutes when exercising for less than one hour. When exercising for longer than one hour, they recommend 3-8 fluid ounces of a carbohydrate/electrolyte beverage every 15-20 minutes. They note the need for a sports drink increases with increased duration workouts1.

References

  1. Simpson, M. R., & Howard, T. (2011). Selecting and Effectively Using Hydration for Fitness.
  2. Coso, J. D., & Estevez, E. (2008). Anaerobic performance when rehydrating with water or commercially available sports drinks during prolonged exercise in the heatApplied Physiology, Nutrition, and Metabolism, 33(2), 290-298. doi:10.1139/h07-188
  3. Campbell, C., & Prince, D. (2008). Carbohydrate-Supplement Form and Exercise PerformanceInternational Journal of Sport Nutrition and Exercise Metabolism, 18(2), 179-190. doi:10.1123/ijsnem.18.2.179
  4. Currell, K., & Jeukendrup, A. E. (2008). Superior Endurance Performance with Ingestion of Multiple Transportable CarbohydratesMedicine & Science in Sports & Exercise, 40(2), 275-281. doi:10.1249/mss.0b013e31815adf19
  5. Khanna, G. L., & Manna, I. (2005). Supplementary effect of carbohydrate-electrolyte drink on sports performance, lactate removal & cardiovascular response of athletesIndian Journal of Medical Research, 121(5), 665-669.
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