Truth about alcohol, protein and exercise.

Cortelli

While interesting, as a former researcher, the study appears to be set-up to give these results...

First off, only 8 subjects were used - not a big sample, although their definaition of athlete looks ok.

Secondly, they used only minimal data points - why not include in the study alcohol only or Carbs only, rather that focus on Protein only, Protein/Alcohol, and Carbs/Alcohol. I understand that the usual push for high output atheltes is protein after exertion, but it seems like they missed some pretty obvious data collection points.

Third, they failed to state that Myofibrillar fractional synthetic rate was higher with both alcohol/protein, and alcohol/carbs, than simply rest - therefore you could argue that alcohol actually helped the athletes. Since the article stated that binge drinking was usually associated with an increased protein intake - I could successfully argue that the alcohol/protein was better for the athlete than rest.

Fourth - they only focused on "athletes who binge drink", and only on the 8 hour period right after simulated game time - what about a longer term study - like how it affected their muscle development or rebuild over the course of a week or month?

Lastly, the study seemed to be set-up to reach these conclusions - based on the above, and the statement at the end of the article:
"Regrettably, there has been difficulty in finding an educational message with alcohol consumption related to sports performance that has resonance with athletes. ... . Our findings provide an evidence-base for a message of moderation in alcohol intake to promote recovery after exercise with the potential to alter current sports culture and athlete practices."

A study with pre-detemined, limited data points, and only 8 participants does not make something "evidence based".

Seems to me the real message - moderation - gets lost in the shuffle.

Thank you for pointing this out! :flowerforyou: I would still love to see something believable about moderate intake -- keep reading about alcohol's effect on testosterone and the importance of T for muscle synthesis, and just really surprised nothing more rigorous out there reflecting moderate regular consumption and effect on synthesis.

ETA: spelling

michael300891

While interesting, as a former researcher, the study appears to be set-up to give these results...

First off, only 8 subjects were used - not a big sample, although their definaition of athlete looks ok.

Secondly, they used only minimal data points - why not include in the study alcohol only or Carbs only, rather that focus on Protein only, Protein/Alcohol, and Carbs/Alcohol. I understand that the usual push for high output atheltes is protein after exertion, but it seems like they missed some pretty obvious data collection points.

Third, they failed to state that Myofibrillar fractional synthetic rate was higher with both alcohol/protein, and alcohol/carbs, than simply rest - therefore you could argue that alcohol actually helped the athletes. Since the article stated that binge drinking was usually associated with an increased protein intake - I could successfully argue that the alcohol/protein was better for the athlete than rest.

Fourth - they only focused on "athletes who binge drink", and only on the 8 hour period right after simulated game time - what about a longer term study - like how it affected their muscle development or rebuild over the course of a week or month?

Lastly, the study seemed to be set-up to reach these conclusions - based on the above, and the statement at the end of the article:
"Regrettably, there has been difficulty in finding an educational message with alcohol consumption related to sports performance that has resonance with athletes. ... . Our findings provide an evidence-base for a message of moderation in alcohol intake to promote recovery after exercise with the potential to alter current sports culture and athlete practices."

A study with pre-detemined, limited data points, and only 8 participants does not make something "evidence based".

Seems to me the real message - moderation - gets lost in the shuffle.

Hi great comments and glad someones having a good look at the original paper.

I do agree that they were looking for results, but then pretty much every paper in history is - as for the small sample size its unfortunately very typical of sport science research. I do not think however that they chose a small sample to help get positive results. Yes a small sample increases risk of type I error (I.e. false positives) but a much larger concern from someone financing a study is type II error (false negatives) in which there isnt a big enough sample to find a result.

I am confident they would have loved to get more people in, which to be honest they should have, but it's important to remember they found quite substantial effects from such a small sample.

As for your second point, another good suggestion. However, remember more trials = less statistical power because you need to do bonferonni corrections and post hoc tests because of the risk of doing repeated comparisons. From the authors perspective, this means more participants when really this study is setting the stage for further work. Also remember what is practically relevant, this study was in athletes who regularly take protein. It would be great to have had a look at alcohol alone but vast majority of athletes would complement a training session with a protein supplement so this is more reflective of the actual population of interest.

Sorry I totally disagree with your third point, its pretty well documented that exercise upregulates protein synthesis regardless of what intake you have, and they are relying on this well documented outcome, to make that conclusion your really just doing some weak correlations. For example, number of ice creams sold correlates to number of burglaries. Does that mean that ice creams result in more burglaries? No its because both occur more in the summer. You can never rely on anything correlational in that way, but I understand what you are getting at in which there wasnt an alcohol only post-exercise control group.

As for your fourth point, would be great to see a training study on this, as that's what everything really comes down to. However, I imagine its hard enough to get ethical approval for a study giving alcohol acutely, let alone for weeks on end.... In addition to that, acute protein synthesis has been shown to be a pretty good indicator of training protein accretion.

In regard to them only focusing on athletes who binge drink, well research suggests 50-60% of athletes who play for team sports "binge" drink after some matches/training sessions and when you are first starting out with research you clearly want to focus on the extreme ends of the spectrum where you are going to see noticeable effects.


In summary, it's not that I disagree with your criticisms: No doubt greater sample size, more variety of control groups, training studies etc all needed but I think you have to remember the context.

This is a seminal study into this area of research and it can be used as a backdrop for further research. I think the findings, even with a small sample, are definitely noteworthy.

Cheers, Mike.

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Doctoral Researcher in Exercise Adaptation and Metabolism:

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michael300891

Back in my glory days 5 pints was a good start or my warm-up if you will except I wasn't working out or playing sports anymore. These days I hardy drink ( maybe 6 occasions all of 2013) but when I do I go all out. The question I would love to have answered is "what effect will alcohol consumption (excessive= more than 5 drinks over a few hours) have on your workouts and protein synthesis in the day(s) after? Besides feeling like crap, dehydrated and not knowing where your wallet or underwear are.

Yes would be great to see what the research says on the longer term effects and moderation drinking over the next few years!

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Doctoral Researcher in Exercise Adaptation and Metabolism:

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michael300891

If you're routinely drinking 6 double vodkas after a workout, you have more to worry about than protein synthesis.

Would be interested in the findings of a more moderate intake.

Yes I totally agree, as I said though no-one has investigated a dose-response relationship yet unfortunately. I would assume however, that one exists... Remember this study is one of the very first to actually look at this in humans, as opposed to rats so it's still early days but the results are pretty conclusive that excessive alcohol is detrimental to muscle gains at this point.

Sounds like an awesome study for a doctoral researcher in exercise adaptation and metabolism to look at First published study, extremely interesting as unknown what mechanism is causing the inhibition in growth, filling a yawning gap amongst those who'd like to train hard and add mass but have a few drinks now and again (i.e., a fair bit less than 6 doubles - and how does 6 doubles = 5 pints of alcohol? always thought a pint was more or less a shot to a shot and a half, basically). I mean, I would stand up and applaud for some data like that :drinker: :flowerforyou:

As someone who enjoys a regular drink and will soon be looking to add muscle mass, I would actually be very, very interested in any studies addressing to what degree modest alcohol consumption inhibits muscle synthesis; anecdotally, regular moderate consumption has not seemed to have a very deleterious affect on my ability to maintain muscle mass during a deficit.

Yes it is the best study I have come across in my academic career so I thought it was suitable for my first myfitnesspal writeup haha!

Yeh the mechanisms are explored quite a bit more in the study than I went into detail here its clearly inhibit of mTORC1 pathway. Interestingly though, it affected the downstream marks of mTORC1 (P70S6K1 etc) without really affecting mTORC1 itself. How that happens is still a definite mystery!

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Doctoral Researcher in Exercise Adaptation and Metabolism:

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michael300891

The study is true. But if applied to everyday life? I doubt anyone is downing 5 pints of alcohol after a workout. And if they are, then they probably aren't seeing results.

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Couldn't agree more. This article is definitely focused at the athlete end. However, from that perspective it really shines a light on certain individuals within a club. I've worked with a few athletes and in most clubs you'll find a couple who drink a LOT of alcohol, having some evidence to present to them in an attempt to educate them into moderation would be great.

However, definitely more research needed for the wider audience.

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Doctoral Researcher in Exercise Adaptation and Metabolism:

Follow me on Twitter (https://twitter.com/Michael300891)