The short answer is “no”. But there is a long answer.
Written by: Matt Fitzgerald
Sports drinks contain a fairly large amount of energy—a little more than half as many calories as the average soft drink. And, like soft drinks, sports drinks get most of their calories from sugar. These facts inspire many label-conscious runners to avoid using sports drinks during training. They see their workouts as opportunities to burn a lot of calories, and they don’t want to “counteract” that effect by taking in a lot of calories at the same time.
This is a reasonable way to think, but it’s mistaken, for more than one reason. First, research has shown that when people consume carbohydrate (such as the carbs in sports drinks) during exercise, they eat less during the remainder of the day. For example, at study conducted at Colorado State University found that when subjects consumed no carbohydrate during a workout, they ate 777 calories at their next meal. But when they took in 45 grams of carbs during a workout, they ate only 683 calories in their next meal. What’s more, the subjects consumed fewer total calories—including workout carbs—during the day in which they exercised with carbs than they did during the day when they exercised without carbs.
A second reason not to avoid using a sports drink during your runs simply because of the calories they contain is that the carbs in sports drinks enable you to run faster and longer, so you burn more calories in you workouts. Runners choose their pace by perception of effort. Consuming carbs during runs reduces perceived effort, so that the runner automatically runs faster at his or her chosen effort level. Studies have shown that athletes self-selected faster workout speeds when they consume carbs during exercise and thus burn more calories in a given time period.
Recently some runners have begun to avoid sports drinks during exercise not because of weight concerns but for a different reason. When carbs are consumed during exercise, the muscles burn less fat. Some runners fear that relying on sports drinks habitually during workouts will artificially limit the general increases in muscular fat-burning capacity that occur in training. This could conceivably limit endurance and hamper performance in longer races such as marathons.
Again, while such reasoning can’t be faulted, it is unfounded. This was proven in a recent study performed at the Australian Institute of Sport. Researchers divided a pool of trained cyclists and triathletes into separate groups and had each of them go through a 28-day block of training, with one group consuming carbs during every workout and the other group abstaining from carbohydrate intake during workouts. Performance was measured before and at the end of the training block in a cycling time trial. The researchers found that performance improved equally—7 percent on average—in both groups despite greater increases in fat-burning capacity in the no-carb group.
While this short-term study found that training with carbohydrate improved simulated race performance by the same amount as training without carbohydrate, literally scores of studies have found that consuming carbohydrate in races and time trials significantly enhances performance compared to competing without carbs. This fact points to one more reason not to avoid using sports drinks in training. Unless you don’t care about your finish time, you’re definitely going to use a sports drink during your races. Naturally, you’re not going to do anything during a race that you haven’t practiced in training. The more often you use a sports drink during training, the more comfortable you will be doing the same in races.
To summarize, there are no fewer than four reasons to go ahead and use a sports drink in your training runs “despite” the calories it contains: 1) It will reduce the amount you eat the rest of the day; 2) It will make you run faster and burn more calories; 2) It will not impede improvements in your fitness by limiting your muscles’ fat-burning capacity; and 4) It will give you valuable practice for using a sports drinks during races, which is essential.
Matt Fitzgerald is the author of Iron War: Dave Scott, Mark Allen & The Greatest Race Ever Run (VeloPress 2011) and a Coach and Training Intelligence Specialist for PEAR Sports. Find out more at mattfizgerald.org.