Post-Exercise Caffeine Helps Muscles Refuel
Most endurance athletes are aware that consuming caffeine before exercise enhances performance in non-habitual caffeine users by stimulating the nervous system and reducing perceived exertion. Now a new study by a team of Australian researchers provides evidence that consuming caffeine after exercise accelerates muscle glycogen replenishment.
Seven trained cyclists participated in the study. The protocol began with a glycogen-depleting ride on the first day followed by a low-carbohydrate dinner. The following day, the cyclists completed a second ride--this one ending in voluntary exhaustion. After this second ride the cyclists were randomly assigned to drink either a carbohydrate drink or a carbohydrate-caffeine drink. Four hours later their muscle glycogen levels were measured. The protocol was repeated on a separate occasion with those cyclists who received the carbohydrate drink the first time receiving the carbohydrate-caffeine drink and vice versa. On average, the cyclists had 66 percent higher muscle glycogen levels four hours after drinking the carohydrate-caffeine drink.
The exact mechanism by which caffeine accelerated glycogen replenishment remains unknown, but the authors of the study, which is soon to be published in the Journal of Applied Physiology, did observe increased blood levels of glucose signaling enzymes with caffeine. This study builds on other recent research showing that the addition of caffeine to a sports drink increase exogenous carbohydrate oxidation during exercise. |
