But for many athletes, that ritual now includes something new: Nutrition 101.
John Swanson, Grand Island Senior High's strength and conditioning coach, gives all of the school's athletes a crash course on sports nutrition at the start of the season.
More students come into high school sports knowing a few of the basics, he said, but there's a lot more they need to learn in order to compete at a top level.
There's a big difference between the specific nutritional plans for a 120-pound cross-country runner and a 250-pound offensive lineman, Swanson said. But there are still a few principles that every student athlete and every adult athlete needs to know.
It all starts with hydration. Swanson recommends that his athletes monitor their hydration by checking their weight before and after practices, since the weight they lose during that time is usually entirely water weight.
The principle remains: Stay hydrated while you're training, and especially before competition.
Swanson also educates students about carbohydrates, proteins and fats, all of which they need.
For carbs: The rawer, the better. Fresh fruits and vegetables are preferred over juices and canned foods, and whole wheats are always better than processed grains.
Protein should be as lean as possible, with chicken breasts and lean cuts of beef and pork recommended.
Fat from some sources (like peanut butter) is much better than others (deep-fried Twinkies). And while fat may not be a big deal during the offseason, it's a no-no on game day.
Another key is balance, said John Kuehn, an assistant professor of biology at Hastings College. "Any time an athlete overconsumes one nutrient class, they underconsume one or more of the others," Kuehn said in an e-mail. "Extremes in any diet are not healthy."
Swanson said young athletes have a higher metabolism than adults, which lessens the dieting pressure but can also encourage them to cut corners, too.