How a late Crouch Christmas made me learn that drinking is bad!

Last Saturday was my family’s Christmas gathering (Yes, I know its February but almost all of the Crouch clan had been snowed/iced in around actual Christmas!). Seeing as it was ‘Christmas’ I saw it as a great excuse to eat the way that is only actually acceptable at Christmas… in excess! However, as I polished off a particular large piece of white chocolate cheesecake, and regretted wearing a waisted skirt to such an occasion, I decided that exercise was needed to start working off the obscene number of calories I’d just consumed… and it needed to start that very day.

Later on that day, I limped back into the house…! The next morning I hobbled down the stairs, clutching the banister like my life depended on it. What I failed to remember in my desire to run off the cheesecake was that I’d also consumed a little bit (ok, ok – a moderate amount…!) of red wine during lunch also (maybe an explanation for the eagerness to exercise?!).  I decided to delve into the scientific literature to see if it could explain the soreness in my limbs!

Quickly, I just want to give a brief overview of the excitation-contraction coupling system of muscle contraction. Contractile elements, myofibrils, are encased in a cell membrane called a sarcolemma. An impulse from nerve fibres ending on the sarcolemma triggers a cascade of events which raises the concentration of calcium ions surrounding the myofibrils. This results in a structural change allowing the muscle fibres in the myofibrils to interact and contract. For greater depth see this great little animation:

When you exercise, especially when you are untrained, muscle fibres are damaged and you feel stiff the day after. This is thought to be due to damage to the excitation-contraction coupling system and disruption in the myofibrils. And on that note, back to the extreme pain I was in… Well, maybe I’m being a little dramatic, but I was very sore!

In my search for some form of explanation I came across a paper which was published last year, “Post-exercise alcohol ingestion exacerbates eccentric-exercise induced losses in performance” (Barnes et al, 2010b). What I had been looking for was pre-exercise alcohol ingestion and its effects, but I decided to take a look anyway.

Despite a previous study a previous study (Poulsen et al, 2007) reaching the conclusion that alcohol imbibed during and after exercise did not affect muscle performance, Barnes et al had previously noted (Barnes et al 2010a) that alcohol consumed after exercise had enhanced the weakness normally seen in muscles after exercise. The team decided to design this study to clear up this contradiction that involved vodka and quadriceps exercises! The authors concluded that:

Completion of 300 maximal eccentric contractions of the quadriceps resulted in significant decreases in all performance measures in the exercising leg only. In accordance with the results of Poulsen et al. (2007), our data confirm that a moderate dose of alcohol has no affect on muscular performance in the days following a drinking episode provided the muscle has not been damaged as a result of strenuous eccentric work. The results of our previous study (Barnes et al. 2010a) are thus due to an interaction between post-exercise alcohol consumption, the damaged muscle and/or the recovery processes initiated by exercise-induced muscle damage.

So when you have exercised enough to cause some damage to your poor muscle fibres, they are in danger of more/prolonged (the mechanisms are unclear as to which) damage when alcohol is consumed! Although this doesn’t explain why being half cut and doing a 5 mile run makes you legs feel like they are filled with lactic acid, it is interesting none-the-less.  As the authors notes “the consumption of large amounts of alcohol by sportspeople, often after competition or training, is common place.” Also, slightly hilariously, in another article, “Alcohol intake appears to be positively associated with team sports where alcohol consumption is often encouraged as a component of team/group bonding and can be related to stress relief.” Umm… I’m sure I have no idea what they are talking about, ahem…

Importantly, the authors note that “the dose used in the current study is considerably lower than levels of alcohol consumption frequently reported by sportspeople suggesting that alcohol use would have to be restricted to an even greater extent if results such as those observed in the present study are to be avoided. Further research is warranted to investigate the dose effects of alcohol use in the post-exercise period.”

So it turns out post match/training celebrations might be doing more damage than you might think! And that’s just the start, alcohol’s effects on human physiology are multiple and diverse (also if you want to know how’d you feel the next day, read my previous blog post on the science of a hangover)!

However I do advise caution in trying to explain to the rugby team on sports night in the student union that they should really not be drinking…!! In the meantime, anyone who could give me any insight into the effects of pre-exercise alcohol consumption’s effects on skeletal muscle would be greatly appreciated!

References:

Barnes et al (2010a) J Sci Med Sport. 2010 Jan;13(1):189-93

Barnes et al (2010b) Eur J Appl Physiol 108:1009–1014

Poulsen MB, Jakobsen J, Aagard NK et al (2007) Eur J Appl Physiol 101:513–523

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