To lose one pound of body fat, you need to create a total caloric deficit of roughly 3,500 calories. That deficit can come from eating less, moving more, or a combination of both. Most people aiming for a steady, sustainable rate of one pound per week need a daily deficit of about 500 calories, and exercise typically contributes a portion of that rather than all of it.
The exact number of calories you should burn through workouts depends on your body weight, the type of exercise you choose, and how much you’re willing to adjust your diet. Here’s how to think through it practically.
Why Exercise Alone Requires a Lot of Time
Your resting metabolism, the energy your body burns just to keep you alive, accounts for 60 to 75% of the calories you use each day. Physical activity makes up only 15 to 30% of your total daily burn. That means workouts are the smaller lever. A joint position statement from the American College of Sports Medicine notes that up to 60 minutes of exercise per day may be necessary when relying on exercise alone for weight loss.
This is why most successful weight loss plans pair exercise with dietary changes. If you cut 300 calories from food and burn 200 through a workout, you hit that 500-calorie daily deficit without either change feeling extreme.
Calories Burned by Common Workouts
Your body weight is the biggest variable in how many calories any given workout burns. A heavier person doing the same activity at the same pace will burn more than a lighter person. The estimates below are based on a 185-pound adult exercising for 30 minutes, drawn from data published by MD Anderson Cancer Center:
- Running at 5 mph: 357 calories
- Aerobics: 306 calories
- Bodyweight exercises, high intensity: 273 calories
- Swimming laps, freestyle: 243 calories
- Water aerobics: 222 calories
- Elliptical, moderate effort: 210 calories
- Cycling, easy pace: 180 calories
- Walking at 3 mph: 159 calories
- Jumping rope, moderate pace: 495 calories
If you weigh less than 185 pounds, expect to burn roughly 15 to 25% fewer calories. If you weigh more, you’ll burn proportionally more. For a 120-pound person, those numbers could drop by about a third.
To frame it simply: a 185-pound person who jogs for 30 minutes burns about 350 calories. To create a 500-calorie deficit through running alone, that person would need to run for about 40 to 45 minutes, assuming no dietary changes. Five days a week at that pace creates a weekly deficit of 2,500 calories, enough to lose roughly three-quarters of a pound per week from exercise alone.
How Much Exercise Per Week for Weight Loss
The baseline recommendation for general health is 150 minutes per week of moderate-intensity activity, things like brisk walking, easy cycling, or water aerobics. But for meaningful weight loss, the evidence points higher. Clinical guidelines from the American College of Endocrinology recommend at least 150 minutes per week as a floor, with better outcomes as the amount and intensity increase.
In practice, most people who lose weight through exercise are doing 200 to 300 minutes per week. That translates to roughly 40 to 60 minutes, five days a week. At a moderate intensity for a 185-pound person, that range burns somewhere between 1,500 and 3,000 calories per week depending on the activity chosen.
High Intensity vs. Steady Cardio
High-intensity interval training burns more total calories per minute than moderate, steady-paced cardio. It also triggers a longer “afterburn” effect, where your body continues using extra oxygen and energy after the workout ends. In one study, exercising at 75% of maximum capacity for 80 minutes produced an elevated calorie burn lasting over 10 hours afterward, while working at 50% of capacity produced an afterburn of about 3 hours. Light exercise at 29% of capacity barely registered any post-workout effect at all.
That said, the practical difference for fat loss is smaller than the marketing suggests. A systematic review of randomized clinical trials found that HIIT and continuous moderate cardio produced similar rates of body fat reduction. HIIT burns more total energy during the session and continues burning slightly more afterward, but moderate cardio burns a higher percentage of fat during the activity itself. The two approaches essentially balance out. Choose whichever you can do consistently, because consistency matters far more than the style of workout.
Your Body Adapts Over Time
One important wrinkle: the calorie math changes as you lose weight. A smaller body burns fewer calories doing the same activity. But the adaptation goes beyond simple physics. Your metabolism actively slows in response to weight loss through a process called adaptive thermogenesis. Your resting energy expenditure drops more than you’d expect from the weight loss alone. Hunger hormones shift as well: leptin (which suppresses appetite) decreases, and ghrelin (which stimulates hunger) increases.
This is why many people hit a plateau after several weeks of steady progress. The workout that created a 300-calorie deficit in month one might only create a 220-calorie deficit in month three. You also become more efficient at familiar exercises, meaning your body learns to do the same movement with less energy.
To push through plateaus, you have three options: increase the duration or intensity of your workouts, reduce your calorie intake slightly further, or introduce new types of exercise your body isn’t accustomed to. Resistance training is especially useful here because building muscle raises your resting metabolic rate, partially offsetting the slowdown.
A Realistic Weekly Target
For most people, a practical goal is burning 1,000 to 2,000 calories per week through exercise while making moderate dietary changes to cover the rest of the deficit. That keeps both sides of the equation manageable. Here’s what that looks like in real workouts for a 185-pound person:
- Walking 3 mph, five days a week for 45 minutes: roughly 1,600 calories per week
- Running 5 mph, three days a week for 30 minutes: roughly 1,070 calories per week
- Swimming laps, four days a week for 30 minutes: roughly 970 calories per week
- Cycling easy pace, five days a week for 45 minutes: roughly 1,350 calories per week
Pair any of those with cutting 200 to 300 daily calories from food (roughly one sugary drink and a handful of chips), and you’ll land close to that pound-per-week pace without feeling deprived on either end. The 3,500-calorie-per-pound rule isn’t perfectly precise for every individual or every timeline, but it remains a reliable starting framework for planning how hard and how often to work out.