Look, itās 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 isnāt cut and dry in terms of how much it might help you, going sober before a race certainly canāt hurt, says Matthew Barnes , a professor of sport and medicine, and researcher on alcohol and exercise at New Zealandās Massey University. āAlcohol is detrimental to pretty much every tissue in the body,ā he explains. āYouāre likely to reduce any alcohol-related decreases in immune function, hormonal disruptions, altered metabolism, excess energy intake, and altered sleep,ā he says. The 5 Coolest Marathons That Have Nothing to Do With Running Of course a beer or two isnāt going to kill you during training; in terms of nutrition, itās most important to be hydrating and fueling properly. But āstudies have clearly shown the consumption of alcohol immediately before a race can negativel...