Calories

You eat, burn, and count them. Here’s how to master them.

Pizza

A measurement of energy in food. Scientists estimate it using a formula that factors in a food’s macronutrient content. The key word here is estimate—things like fiber or how much a food is processed can affect calorie count. It's good to remember about how many calories per gram are in the macronutrients your body uses as fuel:

Carbohydrate: 4 cal/g
Protein: 3
Fat: 9

Thermic Effect 

The calories burned by digestion, or why 500 calories worth of cake make you fatter than 500 of broccoli. The harder a food is to digest, the more energy you burn during the process. Sugar, fat, and refined carbs break down more easily. Cooked foods digest faster than raw, as do processed foods (a burger, for example) versus unprocessed (a steak). Meat and high-fiber foods take more energy to digest and yield fewer net calories.

Calorie Caveat

Your Garmin says you torched 500 calories. You decide you deserve an extra slice of pizza. But you’d have burned nearly 70 calories parked on your chair during that same hour. So your ride probably dispatched closer to 430. “People overestimate what they burn,” says Stephen Secor, PhD, of the University of Alabama. The real amount also depends on factors like body composition and fitness level. The take-home? Be conservative about calories and fuel up on foods that are as close to their natural state as possible.

3,500

Number of calories in a pound of fat. When you take in more calories than you burn, the excess is stored as fat.

How Many You Torch

You’re burning just over one calorie a minute while you sit and read this article. Hop on your bike and you’ll rev that number closer to eight. Here’s roughly the number of calories you incinerate per hour* depending on your speed and effort.

  • Leisurely town spin 272
  • Spinning 10 to 11.9 mph 408
  • Riding 12 to 13.9 mph 544
  • Riding 14 to 15.9 mph 680
  • Riding 16 to 19 mph 816

*Based on a 150-lb. rider in constant motion; not including coasting, drafting, and descending