Look, it’s highly unlikely that giving up booze before running a marathon (or half-marathon, or even a 10K) is going to turn you into Eliud Kipchoge come race day. And while the research isn’t cut and dry in terms of how much it might help you, going sober before a race certainly can’t hurt, says Matthew Barnes , a professor of sport and medicine, and researcher on alcohol and exercise at New Zealand’s Massey University. “Alcohol is detrimental to pretty much every tissue in the body,” he explains. “You’re likely to reduce any alcohol-related decreases in immune function, hormonal disruptions, altered metabolism, excess energy intake, and altered sleep,” he says. The 5 Coolest Marathons That Have Nothing to Do With Running Of course a beer or two isn’t going to kill you during training; in terms of nutrition, it’s most important to be hydrating and fueling properly. But “studies have clearly shown the consumption of alcohol immediately before a race can negativel...