UC San Diego Athletic Performance Nutrition Bulletin
The effects of Alcohol on Endurance Performance
During the work week, runners think longingly of Saturday and Sunday mornings and all those free hours to spend on the trails. But sometimes Friday- and Saturday-night activities don’t jibe with running plans. When an evening of celebrating involves alcoholic beverages (and maybe, gasp, excess), is a trail run the next day still a good idea?
Obviously, a major hangover puts a damper on your motivation — we’ve all been there. But even moderate alcohol intake can negatively impact your body on the trail. While there’s no need for trail runners who are moderate drinkers to suddenly go on the wagon, keep several things in mind.
Alcohol is a diuretic, and after drinking you may become dehydrated, says Stephen Rice, M.D., director of the Jersey Shore Sports Medicine Center. To stay hydrated, drink more water than you’re used to, and bring some on your run, especially if it’s over an hour long.
Also because it’s a diuretic, alcohol depletes your electrolytes (potassium and sodium). And despite what your frat bros may have told you, alcohol — even beer — is not nutritious. In fact, the American College of Sports Medicine (ACSM) states that orange juice has four times the potassium of beer. So eat bananas or drink OJ for potassium, and drink sodium-containing sports drinks such as Gatorade to replace both potassium and sodium.
Alcohol left over in your system impairs your body’s ability to regulate its temperature. In cold conditions, your body could lose heat more rapidly than normally, and in hot weather your body might not release enough heat. Dress in appropriate layers for the outside temperature. If it’s cold, protect your extremities and keep exposed skin to a minimum. Be especially careful not to overheat if you’re running in an unusually hot climate and, again, drink plenty of non-alcoholic fluids.
Even social drinking can have a negative effect on balance and coordination the next day. If you notice that you’re having trouble handling the trail’s rough surface or negotiating obstacles, “Slow down your pace a bit,” recommends Rice. “You’ll be able to handle things much better at a slower speed.”
Be aware that even if you don’t feel a hangover, the lingering effects of alcohol will impede training and conditioning progress and reduce total work output, according to the ACSM. If you’re working up to a goal, a post-drinking run might not bring results.
If you have a race coming up and need to be really on top of your game, the ACSM recommends skipping anything beyond “low amount social drinking” for 48 hours prior to the event. It can take your body up to three days to purge itself of alcohol. One drink (sorry) over the course of an evening is your best bet.