Nutrition, Podcast, Science and Physiology

Alcohol and endurance sports with Ben Desbrow, PhD | EP#357

 September 26, 2022

By  Bernardo Gonçalves

LISTEN TO THE EPISODE HERE:

Ben Desbrow - That Triathlon Show

Ben Desbrow, PhD, is a professor at Griffith University (Queensland, Australia) with academic interests in nutrition and dietetics in both athletic and clinical populations. He also has a foot in the applied side of sports nutrition, being an Accredited Practicing Dietitian, working for example with Rugby League team Gold Coast Titans. In this interview, we discuss the science and practice of alcohol in endurance sports.

In this episode you'll learn about:

  • What is alcohol, and how is it processed and metabolised in the body?
  • The existing scientific research available on alcohol in an athletic context
  • The dose makes the poison: a discussion on alcohol dosage
  • Alcohol and the 4 R's of recovery: refuelling, rehydration, repair and relax (or rest)
  • Can you have a small amount of alcohol with no negative consequences?
  • The zone of regret (and how to avoid it)
  • Alcohol and calories
  • Practical advice around alcohol consumption and habits

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Shownotes

Ben's background

02:49 -

  • I am from Australia, and I started a degree program in exercise science and realised I had as much interest in nutrition during exercise as doing exercise.
  • I ended up doing a dietary qualification and became a dietician.
  • I had a fellowship at the Australian Institute of Sport, which has much recognition for its sports nutrition research.
  • I developed an interest while there, and after, I completed a PhD in Sports Exercise and Nutrition on the effect of cold beverages on endurance exercise.
  • Therefore, we looked at cycling and triathlon performance.
  • Then, I enrolled in a research career focused on factors that affect human performance. (food and nutrition interventions)
  • I also did some clinical research, and those two areas have merged. When you talk about nutrition intervention, you look, for example, at lean body mass, and that has a sports and health impact.
  • We also researched the "dark side" of nutrition.
  • I am a professor at Griffith University and have 7/8 PhD students I supervise. It is fantastic because you can answer multiple questions quickly.
  • I worked for the British Olympic Association before Sydney 2000. I also worked in cricket and rugby.
  • Currently, I work for a professional rugby league team as the head of performance nutrition.
  • Rugby is a collegiate sport similar to rugby union, as we have large bodies running into one another.
  • I also see some athletes individually and have always liked endurance sports. I did some triathlons and one Ironman, which has taught me the experience of eating and drinking during exercise and how to manage that over a long event.

Alcohol

07:20 -

  • We consume alcohol in the form of ethanol. Depending on what you are drinking, the concentration is different.
  • The process of creating ethanol is through the fermentation of sugars. It starts in a carbohydrate form which changes during fermentation due to enzymes.
  • We have three different ways of metabolising ethanol when it comes in: the most common is through alcohol dehydrogenase (ADH). 
  • It happens in the stomach, the small intestine and the liver.
  • The other two paths are microsome alcohol oxidisation (Miox pathway - it tends to activate when you consume large doses of alcohol). It is more malleable, meaning you can train it. If you drink regularly, you tend to see an upregulation in the MiOx pathway.
  • The other is the catalyse pathway, which is another liver enzyme.
  • You see some upregulation with ADH, as with most enzyme systems, but other factors like genetics and body size will determine ADH metabolisation.
  • These pathways metabolise ethanol to produce acetaldehyde. The effects of alcohol come from accumulating these broken-down substances (e.g. hangovers).
  • Alcohol can have a direct effect, but acetaldehyde can also impact other points (inflammatory and cognitive effects)

Time to metabolise alcohol

11:47 -

  • The typical values are 6 grams of ethanol per hour, but in more prominent people used to drink, it can go up to 10+ grams per hour.
  • Therefore, one fast metaboliser will metabolise one standard drink per hour, while a slow metabolise might take twice longer.
  • The most significant difference between genres is the liver's capacity and liver enzyme quantity. However, the more significant difference comes from genetic differences.
  • Genetics can change how you metabolise alcohol and respond to the accumulation of broken-down substances.
  • Some people do not have substantial hangovers. They might have headaches but do not have the more severe side effects.
  • Generally, more robust people can metabolise more ethanol due to liver size and enzyme activity. (a more petite person will metabolise alcohol at a slower rate primarily because of the enzyme activity they have)

Alcohol in the context of endurance sports

14:42 -

  • The work we have done was primarily on post-exercise hydration.
  • We were doing some work with hydration, so I became interested in alcohol research.
  • The first thing you do in a hydration study is control the fluid volume you give someone. (you might increase the sodium or carbohydrate content and evaluate the impact of the nutrient manipulation)
  • The volume you consume is related to the volume retained.
  • When you observe people's behaviour in the post-exercise environment, it is evident that people like to drink large volumes of alcohol. (in particular, beer)
  • People seem not to get sick of drinking beer, which was highly socially accepted.
  • We started evaluating beer and manipulating beer properties so that it could become a better hydration solution.
  • Rather than switching people to beer, we wanted to improve the beer people already consumed.
  • In general, there is a significant gap between practice and research about alcohol's effects on endurance performance.
  • We know much more about berries/cherries and their impact on recovery than alcohol.
  • Part of it is because berries/cherries might be good for us, and we always try to evaluate things that can give us performance gains.
  • In reality, most people drink alcohol in some capacity. For me, it is crucial to guide people on what might or might be helpful to do in their daily lives.
  • Alcohol research comes down to the "Rs" of recovery: refuelling, repairing, relaxing and rehydrating.
  • What alcohol does to each point is interesting in the literature.

Impact of Alcohol on the recovery process

18:36 -

  • When you read literature, you see "grams per kilo of bodyweight" of alcohol. (relative dose)
  • The academic literature considers a moderate alcohol dose of 1 g/kg. If you are 70kg, it is 70 g of alcohol (7 standard drinks).
  • Seven standard drinks would be a long night for me.
  • Triathletes know that they have to get up in the morning and want to feel good, so they would never drink to that extent.
  • When you look at the parameters of recovery, you also need to look at the doses given to people and apply that to what an athlete might consume.

Alcohol impact on refuelling

20:11 -

  • Only one study evaluated refuelling where they gave alcohol and measured muscle glycogen resynthesis.
  • In this study, participants drank 1.5 g/kg of alcohol. They separated people from those that drank alcohol and those that did not. One group received the carbohydrate amount equivalent to the alcohol intake. In another group, they gave the carbohydrate equivalent + alcohol.
  • Compared with a controlled trial, There was no significant difference in muscle glycogen difference between the group with carbohydrate equivalent + alcohol and the group with only carbohydrate.
  • In the group with the same energy intake (alcohol took part of the carbohydrate content), muscle glycogen resynthesis was lower.
  • Alcohol did not influence muscle glycogen resynthesis in this study. (if the carbohydrate content was the same)
  • If drinking leads to poor nutrition choices, muscle glycogen resynthesis is significantly lower.
  • I suspect there were no more studies in that area because a significant dose of alcohol did not affect muscle glycogen resynthesis.

Impact of Alcohol on the repair process

24:13 -

  • Some studies gave 1 g/kg of alcohol. But only one study looked at muscle fibre synthesis and muscle protein synthetic response with 1.5 g/kg. Other studies measured "performance metrics": jump performance and force production; to understand whether the muscle recovered faster.
  • In the study that evaluated muscle fibre synthesis, this dose of alcohol will not be great for the body. If the body is damaged, the recovery process will not occur at the rate we would like.
  • In that study, alcohol consumption impacted muscle protein synthesis in strength and conditioning training. However, we do not have endurance studies looking at mitochondrial resynthesis rates. (endurance adaptations)
  • All studies looking at muscle recovery from strength and eccentric loading (causing muscle damage and evaluating what happens the next day).
  • A series of studies where the researcher lowered the doses (0.5 g/kg or three standard drinks). We see a significantly lower impact on exercise-induced damage recovery at that level.
  • If you have done much running and taken less than 0.5 g/kg of alcohol, there are no proven substantial delays in functional recovery. (if it is a one-off drinking occasion)
  • If you have 1-2 standard drinks, we do not have any studies to prove that alcohol will impact functional recovery.
  • However, we are looking only at acute responses or one-off alcohol intakes relative to body weight.

Impacts on relaxation

29:16 -

  • A study tracked 150 people's sleep for two months, got those people to rate their sleep for a minimum of 60 days, and measured their alcohol intake.
  • Alcohol did not affect sleep duration, but it negatively impacted sleep quality. However, it is a relatively small effect.
  • Nevertheless, we do not have much data on each stage of sleep from individuals and the impacts of alcohol on them.
  • The categorisation of drink intake was 1-5 standard drinks, meaning the maximum intake was 5+ standard drinks. 
  • Therefore, they did not characterise sleep with higher intakes, where we could significantly reduce sleep quality.

Impacts on rehydration

31:37 -

  • The goal was to design a beer that would be better for those that want to drink beer.
  • The answer is that we can design a better beer. Alcohol intake is critical because it is a diuretic once you go above 3.5 % of alcohol by volume.
  • As beer is plant-based, there are many compounds you can play with that can reduce inflammation and improve fluid retention.
  • There are more than ten studies on the topic of alcohol rehydration topic.
  • Our work also looked at manipulating the beer sodium content to see whether you could reduce alcohol quantities and add electrolytes that would hold water better.
  • You get better fluid retention from alcoholic beverages with less than 3.5 % alcohol by volume, with as much sodium as you can tolerate.
  • Sodium tends to dominate the fluid taste.
  • We also looked at the influence of food and fluids. Doing these "clinical trials" becomes too far from real life because that is not how people behave in a free environment.
  • People will drink and eat after exercise. Food is nutrient dense in comparison with fluids.
  • As soon as you start eating, you get more significant water-holding capacity from the nutrients in the food. Even water becomes a good hydration solution when there is food available.
  • The calorie content of alcohol is 29 kJ/g, which is seven kcal/g. A standard beverage with 10 g of alcohol has 70 kcal.
  • If the beverage has some traces of carbohydrates from unfermented carbohydrates, the primary source of carbohydrates will be the mixture of alcohol and fluid. If alcohol is mixed with a "cold-soda beverage", you get many calories from that.
  • A 375 mL 3% beer is a standard drink with 70 kcal. If you go to a 5 % beverage, it will go to 105 kcal.

Practical applications of the academic research

38:16 -

  • Most studies give a single dose of alcohol and evaluate a specific parameter the next day.
  • Alcohol is energy dense, and body composition correlates with performance in triathlon.
  • If you regularly consume alcohol, it will contribute to your total calorie intake.
  • If you want to change your body composition, consuming alcohol regularly will not help.
  • However, I am a fan of "food for enjoyment".
  • One friend of mine is a leading dietician, and the night before he competes in a triathlon, he typically drinks a Guinness.
  • It is about celebrating the start line and recognising that a tiny amount of alcohol does not harm.
  • Food has crucial social, connectedness and enjoyment elements.
  • If we remove that, we lose one of the crucial joys of being alive.
  • You will probably never see the effect of having one standard drink on the next day's exercise performance.
  • The question will be if athletes would then consume more.
  • It comes down to the pattern of drinking and the person's capability to control their alcohol intake.
  • You will not find a study finding effects on performance from having a standard drink 2-3 times per week because the signal is too weak to cause that effect.
  • People should consume alcohol to be in "the pleasure zone". We should not feel guilty about it because we live increasingly stressful lives. If it is the only opportunity that allows us to sit and talk, distress and connect, tiny amounts of alcohol are reasonable.

Effects of one-off drinks for non-drink athletes

42:40 -

  • If you are an unhabituated drinker, you risk feeling some performance decreases the next day. (probably some hangover effects)
  • It isn't easy to measure the impact physiologically.
  • People start researching these topics because they might have constant hangover symptoms and stop drinking.
  • If people stop drinking, they lose the capability to metabolise alcohol, which propagates their previous symptoms if they drink something.
  • Nevertheless, I think most people can handle one standard drink.
  • When you consume alcohol, you have an "ascending limb and a descending limb of the blood alcohol response curve".
  • The "ascending limb" is when you ingest alcohol until it reaches a peak. Then, you start to clear alcohol. You get more euphoria or dizziness symptoms in the "ascending limb".
  • If you consume food, you will dampen the effects, so it will become significantly contextual on how you respond to alcohol intake.

Malaises

46:57 -

  • Alcohol is a good servant when you are in control of it.
  • If you have a quality session the following day and want to be sharp, you do not want to feel malaise.
  • You want to go into that session feeling confident. Therefore, not drinking alcohol on that occasion is a choice you make because you are in control.
  • In other extended low-intensity sessions, you can have two drinks and have that malaise because it is a session where I can balance my alcohol intake relative to where I am in my training program.

Planning training around special occasions

48:50 -

  • If you have flexibility and train beforehand, do it.
  • The other thing is how many drinks you need to have a good night. 
  • You might have 2,3 or more and know it will be a problem the next day.
  • However, that is completely different from having 1-1.5g/kg alcohol. (6-12 standard drinks)
  • Once the night has started and you have a beer in your hand, people will not notice if that is your third or 12th beer.
  • If you moderate the intake, you can still participate in that social event without being hammered the next day.
  • There is a substantial increase in 0 % alcohol beers. Young drinkers are more likely to drink these products if they are in a "glass". (it looks like beer)
  • Smart drinking and making some strategies are wise decisions if you are serious about your sport.
  • You will not perform well if you drink 10+ standard drinks on any day.
  • It might be your best friend's 18th or 21st birthday, so you want to clear some training sessions for a few days.
  • However, sometimes the timings of these things could be horrible.
  • Your mate's birthday can be just before a goal event.
  • And these decisions are tough decisions that we have with young athletes.

Adapting training for amateur/leisure athletes

52:11 -

  • I would do a session in the afternoon before going out. I would have a non-alcoholic beverage every 3rd beverage. 
  • The reason is that when you get to the 5-6th beverage, you will get to the point where it causes diuresis and will lose a lot of fluid.
  • Therefore, you need to increase your fluid intake to avoid being in a "dry state" the following day.
  • The next day I would stay out of the pool. I have never liked hangovers and being in a pool.
  • Doing cycling is the best way to exercise if you do not feel great.
  • If you drink 4-5 standard drinks, you can get up and be acceptable to ride. But if you had 12 drinks, you might still have residual alcohol in the blood, and it is illegal to ride alcoholised.
  • Therefore, you should moderate your morning session because it will not be a quality session.
  • If you want to drink and have a quality training day, you should moderate your alcohol intake and dehydration the next day.

Athlete and body composition

54:39 -

  • Body composition is a sensitive topic because you can get to your goal body composition through strategies that are performance promoting and others that might not necessarily be good behaviours.
  • If alcohol is a non-negligible energy provider in your routine, ditching alcohol is an easy method to lower your calorie intake.
  • Fats are the most prominent energy provider with nine kcal/g, and alcohol comes next with seven kcal/g. Carbs and protein have four kcal/g.
  • Alcohol is a substrate we use during exercise, so ditching alcohol is an excellent way for regular drinkers.

HRV and alcohol

57:02 -

  • HRV is outside my area of expertise (the nervous system responses to heart rate variability).
  • Chronic alcohol intake has parasympathetic control over heart rate variability towards a more sympathetic response.
  • However, other factors influence this parameter as well.
  • My concern is how we address the other factors and how much of an influence alcohol has relative to other variables that may play crucial determinants in that moderator.

Other research areas Ben is working on

59:05 -

  • We are doing work on sleep disruption and muscle glycogen resynthesis. 
  • Participants come to our lab and wake them up on different occasions, and we do muscle biopsies at night and early in the morning.
  • We are evaluating whether sleep disruption influences muscle glycogen resynthesis and to what extent. We expect to present the results within 4-6 months.
  • It will translate to many athletes in many contexts.
  • Sleep is a crucial moderator of how we feel.
  • There are some theories that by waking up during the night, brain glucose increases and perhaps, that affects how much blood glucose may be available to restore muscle glycogen.
  • There are three subcompartments of muscle glycogen.
  • If one of those three subcompartments depletes, the muscle will decrease performance even though there is still muscle glycogen.
  • Some researchers in Danmark are doing fantastic research in this area and looking deeply into the muscle and understanding where muscle glycogen is and why muscle might stop contracting despite the muscle cell having some muscle glycogen left.
  • I have a young student doing some work in non-alcoholic beverages in Australia. We are evaluating whether these beverages can improve drinking behaviours in "binge-drinkers".
  • We have an intergenerational issue in this country where young drinkers drink to get drunk and do not develop a mature relationship with alcohol until they have 10-15 years of alcohol abuse.
  • We are trying to find ways of minimising the harm.
  • Another PhD student is working with Swimming Australia coaches and educating them to reduce REDs and support the development of athletes.
  • I also reflect on how bar attendees serve alcohol to clients. They know they should not serve but do not want to potentiate an aggressive scenario.
  • Rather than not giving them alcohol, why not give clients free or cheap beer they can put into a glass with no alcohol?

Rapid-fire questions

1:07:24 -

What is your favourite book, blog or resource?

Ultramarathon Man: Confessions of an All-Night Runner

 It makes us reflect on how running is at different day periods.

Moreover, the author would not get injured.

The Billionaire Who Wasn't: How Chuck Feeney Secretly Made and Gave Away a Fortune Paperback by Conor O'Clery 

The start of the book has one of my favourite sayings: "Money does not make a person. It unmasks them."

What is an important habit that benefited athletically, professionally or personally?

It is marrying the right person.

Who is someone you have looked up to or who has inspired you?

Charles Feeney is an Irish-American businessman and philanthropist who gave away his fortune secretly for many years.

LINKS AND RESOURCES:


Bernardo Gonçalves

Bernardo is a Portuguese elite cyclist and co-founder of SpeedEdge Performance, a company focused on optimising cycling and triathlon performance. He writes the shownotes for That Triathlon Show, and also produces social media content for each new episode.

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