University of Montana researchers found that endurance athletes (think marathoners) can dig into their favorite fast food in moderation after a hard workout. Moderation is the key.
Brent Ruby is the director of the University of Montana Center for Work Physiology and Exercise Metabolism. He along with graduate student Michael Cramer and a team of researchers in the department's Health and Human Performance reported their research findings in a paper titled “Post-exercise Glycogen Recovery and Exercise Performance is Not Significantly Different Between Fast Food and Sport Supplements.”
"A new study, recently published by the International Journal of Sport Nutrition and Exercise Metabolism, found there was no significant difference in glycogen recovery when cyclists ate fast food after a workout versus when they ingested traditional sports supplements such as Gatorade, Powerbar and Clif products" (Ruby, 2015).
They used 11 male cyclists who participated in rides that lasted 90 minutes to deplete muscle glycogen (a form of carbohydrate stored in the liver). They had the riders consume either fast food (burgers, fries or hashbrowns), nutrition bars, or a carbohydrate beverage.
"The UM researchers analyzed muscle biopsies and blood samples taken in between the two rides and found no differences in blood glucose and insulin responses. Rates of glycogen recovery from the feedings also were not different between the diets. Most importantly, there were no differences in time-trial performance between the two diets" (Ruby, 2015).
Ruby emphasizes that participants ate small servings of fast-food, not super sized portions.