This might not come as a huge surprise, but there’s a barrel load of research out there, compiled by diligent students of nutritional science who sacrifice their time and funds, into the effects of booze on sporting performance.
Take, for example, the latest studies from Australia. Experts from the RMIT University, Bundoora and the Australian Catholic University at Fitzroy in Victoria, the Australian Institute of Sport in Canberra and the Institute of Health and Biomedical Innovation at the Queensland University of Technology joined forces in what must have been one hell of a pub crawl to prove that drinking beers after a bike session may compromise muscle development due to the impairment of protein synthesis.
The specifics of the study show that eight male volunteers completed three training sessions – including resistance work and sprint cycling drills. Immediately, and four hours after each session, the riders consumed whey protein only, alcohol and whey protein, or alcohol and carbohydrate.
The amount of alcohol consumed was equivalent to drinking six strong vodka orange drinks (each one was 60ml vodka, 240ml orange). The researchers found that protein synthesis was reduced by 24 per cent after consuming the vodkas and carbs and by 37 per cent after consuming the alcohol and whey protein chasers.
Protein not poteen
The ‘take home’ message – the first of its kind to specifically demonstrate that alcohol inhibits protein synthesis – is that individuals should avoid alcohol the evening after a hard training session. The recommended recovery strategy from the research team was: focus on post-workout nutrition, prioritising the intake of protein, carbohydrates and fluids. More crucially, of course, booze intake prior to a training session or race is the thing to avoid. But why? Surely plying a liberal amount of any liquid to your system the night before a tough slog is a sound move?
“Not when that fluid comes with an ABV percentage,” explains Mel Wakeman, senior lecturer in Applied Physiology & Nutrition at Birmingham City University. “Alcohol is a diuretic, in other words it makes you pee more and lose fluid. This leads to dehydration before you’ve even started your training ride.”
Wakeman suggests that even though you may feel fine to ride, beneath the surface the side-effects will unwittingly be taking their toll.
“As you start to warm up on your ride you then start to sweat,” she says. “Many cyclists underestimate the amount that they sweat because the movement at speed keeps you feeling cool; evaporative losses will be greater at higher speeds, so you may not realise how much fluid you’re losing through sweat. That is until you remember that you didn’t need to stop for a pee!”
The knock-on effect will seriously hamper your performance. “Being dehydrated means your body has to work harder at maintaining the flow of blood to all the working muscles and deliver enough oxygen and energy to them throughout the ride,” explains Wakeman.
That hangover can manifest itself as the sensation of ‘heavy legs’ in addition to general feelings of fatigue. “If the weather is warm, you are also much more likely to overheat too,” says Wakeman. “It’s really not a sensible move to think that you can just ‘sweat it out’ – even with a decent fluid intake on the ride you are unlikely to make up for the level of dehydration you started with.”
You can't ride it off…
The remnants of last night’s Jägerbombing campaign can have other detrimental effects on the cyclist’s body too.
“Having a skinful will certainly affect your energy levels and the quality of your training session,” insists Wakeman. “Fatigue is likely to set in earlier because your body (the liver) will see removing the alcohol (still left in your body from the night before) as a priority over dealing with any lactic acid produced during the ride.”
As a result you’ll lack strength and power so sprints and climbs will feel more challenging and your reaction time may well be increased – a reduced ability to concentrate and make split-second decisions (like avoiding a wheel, pothole or vehicle) could result in accidents.
“When your body is metabolising alcohol and trying to clear it out of the system, it (the liver) produces less glucose and releases less into the bloodstream,” explains Wakeman. The knock-on effect is that your blood sugar levels will be lower and the body will turn to fat stores for energy. “This is a much less efficient way of making energy so you will feel slower and unable to ride as intensely.”
Alcohol in your system won’t just put greater demands on your liver and your energy conversion abilities, though.
“The exercise itself obviously increases heart rate but so do the effects of dehydration and low blood glucose levels,” explains Wakeman. “Alcohol is also a stimulant that can increase your resting heart rate and increase the stress on the heart; this in turn may reduce your exercise capacity and contribute again to a poor training session.”
Tipple and your ticker
Heavy drinking can even have a sensitising effect on the heart – a big session can trigger irregular heart rhythms and even sudden death. And if that wasn’t a cheery enough reason for opting out of buying another round, there are other issues to consider.
“Chronic moderate to heavy consumption depletes the body of vitamins involved in energy production,” explains Drew Price, sports nutritionist and strength and conditioning coach. “It reduces the rate of muscle recovery by reducing anabolic hormones like growth hormone and testosterone and limiting m-TOR (a metabolic switch that in effect governs the synthesis of new muscle protein) – as well as interfering with glycogen re-synthesis.”
In the case of alcohol, it is converted down to acetate which is then metabolised – which isn’t a very efficient process or an optimal fuel.
Everything in moderation
Of course many of us enjoy drinking in moderation as part of an active social life and often in tandem with our sporting pursuits. To reduce the damage, though, you might want to consider your beverage choices a little more tactically. White spirits – such as vodka and gin – have the fewest calories. They also don’t contain the congeners – chemicals produced during fermentation – which can clog your head and worsen hangovers. Darker spirits, ales and red wine do.
“It’s probably best to enjoy a drink on non ‘key training’ days,” suggests Drew Price. “Generally one or two drinks with food will be fine for most and the major benefit of alcohol is not the resveratrol but the relaxation element. Some evidence supports vitamin B12 consumption and emerging evidence on the use of ibuprofen before sleeping shows it helps, but to prevent a hangover the common sense things apply like sticking to minimally coloured drinks and drinking lots of water in between them.”
Drew also says following competition “exercisers should ensure they are hitting key recovery targets” – consuming 1.2g of carbohydrate per kg of bodyweight and 25g high quality protein, plus adequate fluids. But if you fancy something a little more celebratory, a shandy could be the drink to go for. A recent report in the International Journal of Sport Nutrition and Exercise Metabolism found that a low-alcohol beer (2.3% ABV) and a pinch of salt (bar snacks anyone?) isn’t the worst post-exercise drink you can have. Researchers found that a low-alcohol drink helped restore lost bodyweight and salts, without dehydrating the body, just as well as other non-sports drink options. Chin chin!
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