ARO COACHING
Impact of Alcohol on Sport
By Nicky Ruszkowski

Alcohol is a deeply entrenched cultural norm in many countries, including the United States, the United Kingdom and most of Europe. It is often associated with celebration or reward, and so goes hand in hand with post race or post training celebrations. It's also inextricably linked to how we socialize as adults. It's often used as a coping tool, and not a positive one. Athletes, especially young athletes, can use alcohol as a tool to deal with the incredible pressure associated with high level sport.
There are a myriad of ways that the body responds to alcohol and unfortunately none of them benefit the athlete. The liver is able to metabolize about one alcoholic drink per hour, but this varies based on age, weight, gender, and your alcohol tolerance. Being that many athletes have low body weight, alcohol often has a greater impact.
Immediate impact of alcohol
Consuming alcohol causes a rise in adrenaline (the stress hormone) and the more alcohol consumed, the greater that rise. In contrast, when water is consumed adrenaline levels decrease and noradrenaline levels rise. Alcohol elicits a stress response, it causes the body to release the hormone that prepares the body for action. When this happens too often its incredibly problematic and leads to adrenal fatigue. As athletes, recovery is essential and when the body is in state of stress it is not able to do the work to recover from the exercise session you've just completed.
Alcohol, like caffeine, has a diuretic effect. This means its causes an increased production of urine. A study by Hodson & Maughan (2010) found that when someone is already dehydrated, alcohol doesn't have as much of a diuretic effect but when someone is adequately hydrated alcohol does have a diuretic effect which can lead to dehydration. As athletes the goal is always to be adequately hydrated.
Alcohol also has a significant impact on sleep, specifically it decreases time spent in deep sleep. Contrary to many peoples perception that alcohol helps induce sleep, it actually has a negative impact on the quality of sleep. That rise in adrenaline stops the body being able to achieve the type of sleep needed for the body to do the essential housekeeping that happens during sleep, that includes recovery from exercise.

Longer term impact of alcohol
Alcohol can also decrease reaction time and balance for up to three days post consumption. Additionally alcohol results in a decrease in stamina and ability to generate power. A terrible combination for any cyclist.
Alcohol also inhibits the production of serotonin, melatonin (an essential sleep hormone), testosterone and human growth hormone. These negatively impact the ability to increase fitness and muscle mass, and ability to recover.
Alcohol causes a rise in the stress hormone cortisol. Cortisol has a significant impact on sleep/wakefulness so when elevated will impact quality and duration of sleep. Note: Adrenaline is the stress hormone that works in the short term, while cortisol is the stress hormone that works over the longer term.
Recovery from training is inhibited when alcohol is consumed. It makes it harder for the muscles to use glucose (a primary energy source) and amino acids, so compromises the energy supply to muscles during exercise.
In summary, alcohol negatively impacts athletic performance, lowers positive adaptations from training and inhibits recovery from exercise. If you're looking for easy performance gains then avoid alcohol around times when you're training hard or racing.
References
Barnes, M. J., Mündel, T., & Stannard, S. R. (2010). Post-exercise alcohol ingestion exacerbates eccentric-exercise induced losses in performance. European journal of applied physiology,108(5), 1009–1014. https://doi.org/10.1007/s00421-009-1311-3
El-Sayed, M. S., Ali, N., & El-Sayed Ali, Z. (2005). Interaction between alcohol and exercise: physiological and haematological implications. Sports medicine (Auckland, N.Z.), 35(3), 257–269. https://doi.org/10.2165/00007256-200535030-00005
Hobson, R., Maughan, R., (2010). Hydration Status and the Diuretic Action of a Small Dose of Alcohol. Alcohol and Alcoholism, 45 (4), 366–373. https://doi.org/10.1093/alcalc/agq029
Hong-Brown, L. Q., Frost, R. A., & Lang, C. H. (2001). Alcohol impairs protein synthesis and degradation in cultured skeletal muscle cells. Alcoholism, clinical and experimental research,25(9), 1373–1382.
Shirreffs, S. M., & Maughan, R. J. (2006). The effect of alcohol on athletic performance. Current sports medicine reports,5(4), 192–196. https://doi.org/10.1097/01.csmr.0000306506.55858.e5