That definitely applies to what they put in their bodies on game day.
Take Montreal Canadiens rookie Lars Eller, who has a pretty well-defined game day eating plan that he can reel off with ease, largely because he's gone through it countless times.
First thing in the morning, Eller will have a whey protein shake before heading to the rink for the morning skate. Once there, he'll have two eggs with some fresh fruit and oatmeal before jumping on the ice.
Afterward, he'll have spaghetti with meat sauce, "maybe" a chicken breast and "maybe" a salad for lunch before taking a nap.
Then have a sandwich or some yogurt with cereal about three hours before game time.
And in that whole routine, there is one aspect Eller refuses to waver from.
"The breakfast is the most important part," Eller told NHL.com in March. "For the rest of it, as long as I get the same amount of food it's not that I necessarily have to have, say, a chicken breast, or a specific kind of pasta. It's more the amount of food."
Eller comes from a hockey family -- his father Olaf coaches semi-pro hockey in his native Denmark and all three of his brothers played the game at a high level.
So it should come as little surprise that Eller's choice of religious game day breakfast routine is just about perfect, at least according to Montreal-based nutritionist Pearle Nerenberg.
Nerenberg played varsity for the Cornell women's hockey team while studying nutrition at the Ivy League school, and she attended Montreal's McGill University to get her Master's degree in nutrition. Now that she has her own consulting company, Nutrition Athletica, Nerenberg has focused a lot of her work on youth hockey and is currently working on a nutrition guidebook for hockey parents.
She says that the final meal before a game is the most important of the day, but the process of building the energy required to play hockey at a peak level begins at breakfast.
"You have to think of yourself as having battery packs, and you want them to be as full as they can just prior to the game. So, if you start to fill your battery at breakfast, you don't rely so much on that last meal before a game. If you rely solely on the pre-game meal you probably won't have enough time to fully charge, because the more stressed you are about the game the slower you'll digest food." -- Montreal-based nutritionist Pearle Nerenberg
Nerenberg says that the standard pre-game meal for hockey players of pasta and chicken breast is ideal for loading up on the carbohydrates necessary to get through a game. During a hockey game, she says a player's energy comes 80 to 90 percent through burning carbohydrates, whereas during a regular day that ratio is more like 60 to 70 percent.
This is why she focuses a lot of attention when working with young players on being able to identify which foods are high in carbohydrates and other nutrients, so they can properly plan their intake throughout the day.
And the process begins with breakfast, because having an inadequate meal to start the day can have consequences right up until puck drop.
"There is a domino effect, or a yo-yo effect actually, in that you're creating a hole that you need to fill the rest of the day," Nerenberg says. "If you don't start your day with a proper breakfast, your energy is lower and cravings are higher throughout the rest of the day."
Nerenberg suggests an ideal game day breakfast would consist of carbohydrate-rich whole grains -- ideally a bowl of oatmeal -- the fiber found in fresh fruit and some protein like eggs, dairy products, or even adding protein powder to your oatmeal.
So basically, she's telling Eller not to change a thing, and young players would be wise to follow his lead.