Marathon Day Dos and Don'ts: What Really Works on Race Day

When you're standing at the start line of a marathon, marathon day dos and don'ts, the practical choices you make in the hours before and during the race that determine how you feel at the finish. Also known as race day strategy, it's not about luck—it's about what you did (or didn't do) in the days leading up, and the tiny decisions you make when your body is screaming to quit. Most runners focus on training, but the race itself is where everything falls apart—or comes together. And it’s not because you’re not fit. It’s because you drank too much water at mile 5, ate a new energy bar you never tried, or wore brand-new socks because you thought they’d be "cooler."

Here’s what actually matters: running nutrition before marathon, the food and drink you consume in the 24 hours leading up to and during the race. Also known as fueling strategy, it’s not about loading up on pasta the night before—it’s about keeping your blood sugar steady, avoiding gut chaos, and knowing exactly what your body can handle. A study from the Journal of the International Society of Sports Nutrition found that runners who stuck to familiar foods finished 12% faster on average than those who tried something new on race day. That means no exotic smoothies, no gluten-free muffins you just discovered, and definitely no energy gels you sampled once at a store. And then there’s marathon hydration, how and when you drink fluids during the race to avoid cramps, dizziness, or worse. Also known as fluid balance, it’s not about chugging water at every station. Too much can cause hyponatremia—a dangerous drop in sodium levels. The smart runners sip every 15 to 20 minutes, matching their sweat rate, not the crowd’s pace. And don’t forget pre-race routine, the consistent set of habits you follow every race day to calm nerves and activate your body. Also known as race day ritual, it’s what gets you from bed to start line feeling in control. For some, it’s a light jog. For others, it’s listening to the same playlist, wearing the same hat, or eating the same toast with peanut butter. Whatever it is, don’t change it.

What you shouldn’t do? Skip your warm-up because you’re "saving energy." That’s a myth. A 10-minute jog and some dynamic stretches wake up your muscles and prep your nervous system. Don’t wear new shoes, even if they’re the "lightest ever." Your feet will blister. Don’t try to match the guy next to you who looks like he’s flying—he’s probably going to hit the wall at mile 20. And don’t check your phone for updates or social media once you start. Your focus needs to be on your breath, your stride, your rhythm.

Marathon day isn’t about proving something to anyone else. It’s about honoring the months of early mornings, sore legs, and quiet sacrifices. The dos and don’ts aren’t rules—they’re your last chance to make sure your body gets the respect it earned. What you do in these final hours will echo in every step after mile 18. And when you cross that line, you won’t be wondering what went wrong. You’ll just know you did it right.