Int J Sport Nutr Exerc Metab. 2015 Mar 26. [Epub ahead of print]
Post-exercise Glycogen Recovery and Exercise Performance is Not Significantly Different Between Fast Food and Sport Supplements.
Cramer MJ1, Dumke CL, Hailes WS, Cuddy JS, Ruby BC.
Author information
Abstract
A variety of dietary choices are marketed to enhance glycogen recovery after physical activity. Past research informs recommendations regarding the timing, dose, and nutrient compositions to facilitate glycogen recovery. This study examined the effects of isoenergetic sport supplements (SS) vs. fast food (FF) on glycogen recovery and exercise performance. Eleven males completed two experimental trials in a randomized, counterbalanced order. Each trial included a 90-minute glycogen depletion ride followed by a 4-hour recovery period. Absolute amounts of macronutrients (1.54 ± 0.27 g·kg-1 carbohydrate, 0.24 ± 0.04 g·kg fat-1, and 0.18 ± 0.03g·kg protein-1) as either SS or FF were provided at 0 and 2 hours. Muscle biopsies were collected from the vastus lateralis at 0 and 4 hours post exercise. Blood samples were analyzed at 0, 30, 60, 120, 150, 180, and 240 minutes post exercise for insulin and glucose, with blood lipids analyzed at 0 and 240 minutes. A 20k time-trial (TT) was completed following the final muscle biopsy. There were no differences in the blood glucose and insulin responses. Similarly, rates of glycogen recovery were not different across the diets (6.9 ± 1.7 and 7.9 ± 2.4 mmol·kg wet weight- 1·hr-1 for SS and FF, respectively). There was also no difference across the diets for TT performance (34.1 ± 1.8 and 34.3 ± 1.7 minutes for SS and FF, respectively. These data indicate that short-term food options to initiate glycogen resynthesis can include dietary options not typically marketed as sports nutrition products such as fast food menu items.
It’s quite different to measure specific chosen parameters, for example glycogen resynthesis and exercise performance on a bicycle, than to determine effect on body composition and strength over time, or ability to weight train intensively with volume.
I’m able to access only the abstract presently, which is vague on what was being compared with what, simply “sports supplement” with macronutrient figures but no specification as to types of carbohydrate, protein, and fat, vs “fast food” of same otherwise unspecified composition. Glucose, complex carbs, sucrose, fructose, we do not know from the abstract. (The full article undoubtedly will say.)
Apparently the two things each being compared were about 8% protein, 68% carbs, and 18% fat. Not what I’d call quality post workout nutrition in either case, though apparently this was aerobics oriented.
Is what you eat when you are burning net calories less of a problem though? Are omega 6s not as bad if you are during a stretch of the day where you are burning more than you are eating? I think its true with fructose at least.
I would just go by observation. I’ve known guys who did huge endurance work and had the worst crap to fuel it, and by all appearances did just fine at least for what they were wanting to do and be. I think it is different with weight training and bodybuilding. I’d welcome and encourage anyone to try different methods and see for themselves, which is what’s relevant rather than findings of glycogen resynthesis rate etc.
I made some of the best gains of my life eating absurd amounts of crap.
I got fat too, but I’m willing to bet if I didn’t grossly pass my caloric needs I would have looked fine.
Personally, I don’t think food quality is all that important.
I think people should aim to eat nutrient dense foods most of the time for general health, but for body composition and gains my own anecdote is nah.
Well, when I was 20, eating a chocolate bar and chocolate milk went to my chest. Now, I smell a donut on the way to the gym car park and my gut grows an inch.
If someone serious about their health, why would they want to put fast food in their system, regardless of the effect it may or may not have on body composition?
Bill is right. It’s wrong to look at a single variable and only on short-term impact.
Eating “crap” might restore glycogen as well, but that doesn’t mean that it will lead to as much muscle growth. Furthermore what will be the impact on fat gain over time? And most importantly what will be the body composition impact over time? Eating fast food can cause systemic inflammation and lead to poor insulin sensitivity over time. So if you abuse fast food thinking that it’s "anabolic’, you might eventually get a bad surprise when your insulin sensitivity sucks and your fat cells are inflamed: it will become harder and harder to store nutrients in the muscle/build muscle and increasingly easier to store fat.
Hey when I competed in Olympic lifting about 15 years ago I was the poster child for eating fast food post-workout. After every session I would go to A&W and eat 4-5 burgers and a large fries (I often trained twice a day). Did I get stronger? YES. But I also go a whole lot fatter and had amazingly poor insulin sensivity and it took me 18 months straight of low carbs dieting to get into decent shape. And I don’t even wanna know what all that junkdid to my health!