Calories are a measure of the energy your body uses to fuel both everyday functions and exercise. Calorie loss, or energy expenditure, depends on various factors, including the intensity and duration of the activity, the distance covered, terrain, elevation changes, and body weight. Higher intensity activities burn more calories over time.

To calculate energy expenditure, you can use METs (metabolic equivalents of a task). One MET represents the energy used at rest. For example, a brisk walk at roughly 4 mph equals 5 METs. The formula to estimate calorie burn is: METS x 3.5 x body weight in kg / 200 = estimated calorie burn per minute.

For a 200-pound (90.7 kg) adult walking briskly at 4 mph (5 METs), the calculation would be: 5 METs x 3.5 x 90.7 kg / 200 = 7.9 calories burned per minute. Walking for 30 minutes would burn approximately 237 calories.

You can increase the calorie burn of your walking workouts by:

• Walking faster
• Walking uphill
• Walking at intervals of slow and fast speeds
• Pumping your arms while walking
• Walking in shallow water or sand
• Wearing a weighted vest
• Adding lower-body exercises like lunges or squats during your walk

While burning calories can be a motivator, it's also important to find intrinsic motivation for exercise, such as enjoying the activity itself and the way it makes you feel. This can help you maintain a consistent exercise routine over time.