By now, many athletes have heard about the recent study that concluded that fast food and sport supplements, taken after exercise, result in similar recovery. This information has been taken by many people to mean that they can do a little workout, then eat junk without consequences. Let’s look at the data and see if that is true.
This trial was conducted with eleven men (average age 27.7 years) who were familiar with moderate to high intensity exercise. The study subjects had good fitness with an average maximum power output of 309 watts. The trial had a randomized, cross-over design. The subjects abstained from exercise for 24 hours and food for 12 hours before each trial. Each subject then completed a 90 minute glycogen-depleting ride on an indoor cycle ergometer. They could drink all the water they wanted. After the 90 minute ride, the study subjects rested and ate either fast food or sports supplements, at 0 and 2 hours, during a 4 hour recovery period. Following the recovery period, the subjects completed a 20 km time trial on the same indoor cycle ergometer. The subjects, as already mentioned, were randomized and ate either fast food or sport supplements on the day of their first time trial. When the subjects returned for their second time trial, exactly the same protocol was followed, except they ate the opposite food items.
The foods the participants were fed, whether fast food or supplements, contained the same absolute amounts of macronutrients. These were 1.54, 0.24, and 0.18 grams/kg of body weight for carbohydrate, fat, and protein, respectively. The fast food items were from McDonald’s and included: hotcakes, hashbrowns, orange juice, hamburgers, Coke, and french fries. The sports supplement items included: Gatorade, Kit’s Organic PB, Cliff Shot Bloks, Cytomax, Power Bar Recovery PBCC, and Power Bar Energy Chews.
Aside from performance measures on the cycle ergometer, the researchers also obtained data from muscle biopsies (for glycogen levels), blood sampling (for glucose, insulin, and lipid levels), and a “gastrointestinal discomfort questionnaire.”
The results are interesting, but, when the structure of the study is considered, not very surprising:
- Time trial times were not significantly different between the two groups.
- Muscle glycogen concentrations post-exercise were not significantly different between the two groups at either 0 or 4 hours of recovery.
- Serum glucose concentrations were not significantly different between the two groups at 0, 30, 60, 120, 150, 180, and 240 minutes of recovery.
- Serum insulin concentrations were not significantly different between the two groups at 0, 30, 60, 120, 150, 180, and 240 minutes of recovery.
- Blood levels of total cholesterol, high-density lipoproteins, low-density lipoproteins, and triglycerides were not statistically different at 0 and 4 hours of recovery.
- Feelings of sickness and discomfort were not statistically different between the two groups at 0, 1, 2, 3, and 4 hours of recovery.
This study has been portrayed to say that fast food can be used as a source of recovery nutrition. But please note that this trial of fast food vs sport supplements was actually structured to compare the effects of these sources of nutrition on replenishing glycogen (energy stores) in preparation for a time trial. This trial was not equivalent to the now-famous body of research that supports consuming chocolate milk after completing all exercise.
Another caveat to consider is the real-world applicability of measurement of the foods used in the trial. Most people over-order food in fast food establishments. In the example of this trial, the second fast food feeding consisted of a hamburger, medium Coke, and small fries. To someone who has been fasting, then exercising, these portions may seem quite meager. Intuitively, it appears to me that sports nutritional supplements, with detailed packaging, may be easier to eat in appropriate quantities.
The bottom line is that energy-starved muscles will accept any source of replenishment. When the macronutrients, carbohydrates, protein, and fat, are equivalent, the results of replenishment are going to be the same before and during an exercise challenge.
Cramer MJ, Dumke CL, Cuddy JS, et al. Post-exercise Glycogen Recovery and Exercise Performance is Not Significantly Different Between Fast Food and Sport Supplements. Int J Sport Nutr Exerc Metab. 2015 (not yet published)
Pre-publication material is available at: