I originally came here with the intention of writing a blog about how to time your pre and post workout meals, what to eat, the ratio of carbs:protein, etc. But as I got deeper into my research I realized that's not what this blog was going to be about...
The peer-reviewed studies refute the existence of a post-workout anabolic window as well as the usefulness of nutrient timing (1, 2, 3) while articles more of the "pop-fitness" type still suggest that nutrient timing makes a significant difference in your training results (4, 5). It's interesting that the scientific method and it's resulting literature can so clearly show mixed and limited results supporting the efficacy of pre/post workout nutrition and yet if you just google "pre/post workout nutrition" you'll be flooded with articles and blogs about how carb/protein intake timed directly, delicately, and unforgivingly around your workouts is the only way to see results.
...I may be exaggerating just a bit there, but many of these pop-fitness sources really try to shove nutrient timing down your throat as the end all be all for fitness related nutrition. In fact, I did the google search mentioned above and on the first page 8/10 of the results included articles that stressed the timing of pre and/or post workout meals. Here they are:
"The name of the game is speed."
"Essential to achieve results."
"Timing is everything."
"Time is of the essence."
"As soon as possible"
"1-2 hours before, 1-2 hours after"
"Smartly timed snacks"
The other two of the resulting articles are actually linked in the sources below. They both take a more neutral stance explaining that timing may not be the most important aspect of fitness-related nutrition but still providing guidelines for what/when to eat before and after a workout. (4, 5)
My 'research' was limited to sources of the pop-fitness nature until just before writing this blog, which is probably why I was so sure I'd be writing about the how, the what, and the why of nutrient timing. But then I read the two meta-analyses and the experiment linked below spearheaded by two huge names in the fitness nutrition and research industry, Brad Schoenfeld and Alan Aragon, and realized that much of the hype regarding protein and carb intake surrounding a workout (and especially the protein intake after a workout -- that "anabolic window of opportunity ) is just that; hype.
I think the easiest way to divulge the information I gathered would be in bullet-point fashion. So, below you'll find the main ideas, the limitations of the studies, and the takeaway from my research. You'll also find all the sources I used linked at the very bottom of the blog, so you can investigate further to draw your own conclusions.
1. Evidence for the benefits of pre/post workout nutrient timing is limited and conflicting at best. Limitations are discussed below. (2, 3)
2. But, based on the evidence we do have, it certainly couldn't hurt to implement pre/post workout nutrient regimens and may even be catalytic to hypertrophy. (3)
3. However, as compared to total nutrient intake, protein timing "would at best appear to be a minor consideration." (3)
4. The so-called anabolic "window of opportunity" does not exist. (1, 2, 3)
5. Carbs and protein are the nutrients you'll want to focus on for your meals before and after working out. (4, 5)
6. It may be redundant to focus heavily on BOTH the pre and post workout meal. If the pre workout meal is sufficient the post workout meal becomes much less important and vice versa. (3, 5)
LIMITATIONS OF THE CITED STUDIES
- THE SAMPLE: Many of the studies are performed on untrained subjects. (1, 2, 3) This means we have no way of knowing, yet, whether or not results would differ on a group of seasoned lifters or athletes. This becomes especially important when considering that the RDA for protein intake differs pretty significantly for the untrained versus the trained population. (3)
- THE LENGTH: The studies occur over relatively short periods of time; weeks, usually. Hypertrophic adaptations are not quickly occurring phenomenons, so it may be useful to have a longer-lasting study in accordance with the time frame of hypertrophy or strength gain. (1)
- THE MEASUREMENT: It is suggested multiple times that the measurement tools had limitations that may have prevented wholly accurate results. (1, 2)
- THE METHOD: Most studies implemented pre AND post workout regimens, which makes it impossible to discern whether the effects are due to the pre, the post, or both the pre and post workout intakes. (1)
- THE DOSAGE: Many of the studies use relatively low protein dosages. This may not be comparable to real life implementation and therefore the results cannot be applied to real life situations. (1)
Honestly? Pre/post workout nutrition, as the literature currently shows, isn't all that and a bag of chips. If your calorie intake as well as your carb/fat/protein intake is appropriate and correct every day then it may be worth your efforts to try timing your carbs and protein more directly around your workouts while leaving fats for earlier and later meals. The evidence is mixed, and while it doesn't show frequent and significant positive implications of nutrient timing on hypertrophy or strength there are a few studies that support the efficacy of pre/post workout nutrient timing. (2, 5)
However, if the rest of your nutrition is not on point, you'd be better off focusing first on honing in those calorie/carb/fat/protein intake numbers. The evidence DOES suggest multiple times that total nutrient intake is more important the timing of those nutrients. (1, 2, 3, 5)
(1) Aragon, Alan Albert, and Brad Jon Schoenfeld. “Nutrient Timing Revisited: Is There a Post-Exercise Anabolic Window?” Journal of the International Society of Sports Nutrition 10 (2013): 5. PMC. Web. 6 Mar. 2017.
(2) Schoenfeld, Brad Jon et al. “Pre- versus Post-Exercise Protein Intake Has Similar Effects on Muscular Adaptations.” Ed. Justin Keogh. PeerJ 5 (2017): e2825. PMC. Web. 6 Mar. 2017.
(3) Schoenfeld, Brad Jon, Alan Albert Aragon, and James W Krieger. “The Effect of Protein Timing on Muscle Strength and Hypertrophy: A Meta-Analysis.” Journal of the International Society of Sports Nutrition 10 (2013): 53. PMC. Web. 6 Mar. 2017.
(4) Curcio, Peter. "Pass The Protein Shake: Digging Into Pre- And Post- Workout Nutrition." www.breakingmuscle.com (2012).
(5) "Pre & Post Workout Meal - What To Eat Before And After Working Out." www.acaloriecounter.com