Many runners are still stuck in the dark ages when it comes to sport drink use. Ingesting a sport drink during workouts and competitions lasting longer than an hour and during some very intense running sessions can enhance carbohydrate oxidation in the muscles and thus advance both endurance and speed.
Research has established the overall effectiveness of sport drinks and has shown runners how much to consume, how to time their sport drink intakes, and how to combine carbs within a sport drink in order to maximize carbohydrate absorption. The following excerpt about fueling during a run is from Running Science by Owen Anderson.
What's the Best Way for Marathon Runners to Hydrate?
Research suggests that sport drink use is especially beneficial during a glycogen-depleting running event like the marathon. In a study carried out by Robert Cade, the inventor of Gatorade, and his colleagues at the University of Florida, 21 experienced marathon runners (18 men and three women) from the Florida Track Club were divided into three groups of roughly equivalent running ability. Members of one group drank plain water while running a marathon; those in a second group consumed a glucose-electrolyte solution of 5 percent glucose with sodium, chloride and phosphate; and subjects in a third group ingested a mixture that was half water and half glucose-electrolyte solution, yielding a 2.5 percent concoction. To ensure maximal muscle glycogen levels at the start of the race, all 21 runners carb loaded during the days prior to the marathon, relying on diets that were rich in carbohydrate.
Ten of the runners experienced difficulties during the last third of the race that caused them to drastically reduce pace from 6 to 9 or 10 minutes per mile or to adopt a walk-run strategy for finishing. This dropoff in speed took place in 67 percent of the runners who drank only water during the competition. Fifty percent of the athletes who consumed the half-strength beverage hit the wall in this way. Only 29 percent of the glucose-electrolyte drinkers suffered from such precipitous falls in pacing. Overall, use of the sport drink reduced the risk of bonking.
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