The reason: Running takes more effort—you lift your body weight off the ground with every step (Go from walking to running in just 30 days!). Not so with walking; one foot is always on the ground. Also, since running is higher intensity, you’ll burn more postworkout calories because it takes longer for your body to recover.  Even though you’re burning fewer calories, don’t let these numbers discourage you from walking with your friend. Exercising with someone can make you less likely to skip your workouts. Walking is also easier on your joints, so you can do it every day with less risk of injury. In fact, by being more consistent, over time you may burn more calories walking than running. In the meantime, here’s how to make up the calorie shortfall without scrimping on food. Walk an extra mile You can do it anytime, and if you go at a 4 MPH pace, it will take only 15 minutes. Speed up Walk for the same amount of time as you usually do, but go a half-mile per hour faster. Kick it into high gear Sneak in a 3 4-mile run before or after your walk with your friend.