Why Eating Enough Is Important for Fitness

Consider everything you do in a day: walking, working out, socializing, breathing, thinking. Then add the processes that your body undergoes to support these activities: digesting, circulating and filtering blood, fighting infection, building or rebuilding muscle and other tissues.

“All those outputs require energy inputs to work,” says Ogden. “Energy input comes from the calories — ­energy — in food.”

Before you even think about the food sources of that energy, you need to be sure you’re getting enough ­energy in the first place.

“If you’re not getting enough calories, your vitality, energy, strength, and motivation can all decline,” says performance and transformation specialist Angelo Poli, ISSA.

So how much energy is enough? “That depends on what the demand is,” Ogden notes. The energy required to fuel a workout is only one small part of the equation. A larger contributor to daily energy expenditure, she explains, is non-exercise activity thermogenesis, or NEAT: the movements you do as part of everyday living. People with desk jobs and sedentary hobbies burn less energy via NEAT than those whose jobs and hobbies require walking or other physical exertion.

“If you’re not getting enough calories,
your vitality, energy, strength,
and motivation can all decline.”

There are formulas for determin­ing how many calories you need based on weight, gender, and activity level. For some people, tracking calories can be a useful tool to build awareness and ensure adequate fueling. For others, calorie counting can feel time-consuming and joy­less, or is linked to restriction and disordered eating.

Tuning in to your body’s ­hunger and satiety signals can be an ­easier and more self-compassionate ­approach for making sure you’re ­eating enough.

Simply put, the more you move, the more fuel you need. Try to eat an amount that keeps you energized throughout the day without leaving you overly full or tired.

This might be difficult if your fitness journey has included weight loss or food restriction. To start, give yourself permission to eat whenever you feel hungry. Learn to recognize mild sensations of hunger — and honor those cues before you become ravenous. (Find out more about the principles of intuitive eating at “The 10 Principles of Intuitive Eating” and try the easy add-ons at “How to Add More Fiber, Protein, and Antioxidants to Your Plate” to get more of the nutrients that matter.)