In recent years, the sports supplement industry has swelled. New products on the market claim to be better concentrated to deliver the greatest performance enhancement or post-workout recovery results over any natural food product. In contrast, with the rising tide of obesity in America, fast food has gotten a bad rap for being supremely concentrated with nutrient-scarce filler substances that lead to metabolic disturbances and increase the risk of heart disease later in life.
It seems unlikely that high-level athletes would opt for fast food over supplements to fuel their ever-repairing bodies, especially with the low-quality stigma attached to these dietary options. To assess this speculation, Cramer et al. (2015), tested the efficacy of carbohydrate replenishment in a randomized control trial comparing fast food and sports supplements post-workout. Their hypothesis presumed that common fast food items can provide adequate macronutrient replenishment equal to that of sports supplements.
The results agreed with the hypothesis: The rates of glycogen recovery were similar. No statistically significant difference in performance showed in the subsequent 20-kilometer time trial between groups, either.
The Details of the Study
The study involved 11 recreationally active men split into two groups: One received carbohydrate replenishment via fast food, and the other via sports supplements. Each had matching macronutrient ratios. Both groups were subjected to a 90-minute glycogen-depleting cycle ride, followed by a muscle biopsy of the vastus lateralis and a four-hour recovery period in which post-workout feeding took place at zero and two hours.
After the four-hour recovery period, the subjects took part in a 20km cycle time trial. Subsequent muscle biopsies were taken from each subject for analysis of their glycogen status. There was no statistical difference between the groups on any of the measured parameters, including muscle glycogen recovery, muscle glycogen concentration post-exercise, blood glucose, insulin, and blood lipid levels.
This study was well-designed, but lacked a strong sample size to warrant the best evidentiary support. There were surveys given to each of the participants to check for satiety levels in regards to zero- and two-hour post-workout feedings. The sports supplement group admittedly felt more full after the sports supplement feed at two hours, but otherwise expressed no feelings of discomfort or sickness from consuming either the fast food or the sports supplements.
The study was supported by previous research. Evidence from that showed that immediate glycogen replenishment post-workout can improve recovery by 45%, and a subsequent feed at two hours post-workout further enhances the storage process. The greatest concern would surround the “regulation” of dietary intake in the 24 hours prior to testing. The participants were told to track their daily intake and then repeat that diet the day before the second trial (seven days later), in order to mimic glycogen content going into the test. Undoubtedly, this can result in widely differing muscle glycogen content if the macronutrients were not fixed and standardized for the pre-test protocol. The study lacked standardization in this regard, but overall it was well methodized.
Innumerable research supports the correlation between fast food consumption and dyslipidemia, cardiovascular risk, and the obesity epidemic. However, there has been minimal research conducted on the acute effects of this food intake in healthy and active individuals. This type of study would be dangerous in the hands of the media, which could blow the data widely out of proportion. The population tested consisted of recreationally active men, and thus cannot be globalized to fit sedentary populations, high-level athletes, or even women. A longitudinal study is needed to determine the long-term effects of these dietary choices before fast food is given the green light for healthy, active populations.
This does not mean we shouldn’t challenge the idealized use of sports supplements as opposed to natural food sources, which may achieve the same effect with less artificial processing. Professional athletes will not likely adopt this habit any time soon; especially without valid and reliable evidence that fast food is healthy enough to support performance and training recovery in the elite world, where glycogen processing and efficiency reach an entirely new level.
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Cramer, M. J., Dumke, C. L., Hailes, W. S., Cuddy, J. S. & Ruby, B. C. (2015). “Postexercise glycogen recovery and exercise performance is not significantly different between fast food and sport supplements.” International Journal of Sport Nutrition and Exercise Metabolism, 25, 448-455.