A typical workout burns somewhere between 200 and 600 calories per hour, depending on the activity, your body size, and how hard you push. That range is wide because calorie burn isn’t a fixed number for any exercise. It shifts based on your weight, intensity, fitness level, and even the temperature outside. Understanding what drives those differences helps you get a realistic picture of what your workouts actually cost in energy.
Calorie Burn by Activity Type
Scientists measure exercise intensity using METs, or Metabolic Equivalents of Task. One MET is the energy you burn sitting still. An activity rated at 8 METs burns eight times that amount. You can estimate calories per minute with a simple formula: METs × body weight in kilograms × 0.0175. For a 155-pound (70 kg) person, that means a 7-MET activity burns roughly 7.3 calories per minute, or about 440 calories per hour.
Here’s how common workouts compare using standardized MET values from the Compendium of Physical Activities:
- Running at 5 mph (12-minute mile): 8.3 METs, roughly 515 calories/hour for a 155-lb person
- Running at 10 mph (6-minute mile): 14.5 METs, roughly 900 calories/hour
- Cycling at moderate effort (12–14 mph): 8.0 METs, roughly 495 calories/hour
- Leisure cycling under 10 mph: 4.0 METs, roughly 250 calories/hour
- Swimming laps, vigorous freestyle: 9.8 METs, roughly 605 calories/hour
- Breaststroke swimming: 10.3 METs, roughly 640 calories/hour
- Weight training, moderate (8–15 reps): 3.5 METs, roughly 215 calories/hour
- Weight training, vigorous effort: 6.0 METs, roughly 370 calories/hour
Cardio exercises consistently top the list for raw calorie burn per hour. Running, cycling, and swimming at moderate to high intensities all land in the 8–10 MET range, while even vigorous resistance training stays closer to 5–6 METs. That doesn’t make strength training less valuable for body composition, but minute for minute, it burns fewer calories during the session itself.
Why Body Weight Changes Everything
A heavier person burns more calories doing the exact same workout at the exact same pace. This is straightforward physics: moving a larger body requires more energy. That MET formula multiplies directly by body weight, so a 200-pound person running at 5 mph burns about 665 calories per hour, while a 130-pound person running the same speed burns closer to 430.
Muscle mass plays a role too, though it’s more modest than fitness marketing suggests. Each pound of muscle burns roughly 4.5 to 7 calories per day at rest. Adding 4 to 5 pounds of muscle through a strength training program increases your resting metabolism by about 50 calories per day. That’s meaningful over months and years, but it’s not the dramatic “muscle is a calorie-burning furnace” effect you’ll sometimes hear about. The bigger impact of muscle mass is that it lets you train harder and at higher intensities, which is where the real calorie burn happens.
The Afterburn Effect Is Real but Modest
Your body doesn’t stop burning extra calories the moment you stop exercising. This post-exercise calorie burn, called excess post-exercise oxygen consumption (EPOC), keeps your metabolism elevated as your body recovers, replenishes energy stores, and repairs tissue. The question is how much it actually adds up.
The answer depends heavily on intensity. In one study, researchers compared two workouts that each burned 500 calories during the session. The higher-intensity bout (at 75% of maximal effort) produced an afterburn of about 45 calories, while the lower-intensity version added only 24 calories. That’s a meaningful difference in percentage terms but a small number in absolute terms.
Longer, harder workouts push the afterburn higher. Eighty minutes of exercise at 75% of maximum effort produced an afterburn of about 150 calories in one study. But most people aren’t sustaining that intensity for 80 minutes. After a typical 30-minute moderate cycling session, the afterburn measured just 15 to 31 calories. For a standard 30-minute workout at moderate intensity, expect the afterburn to add somewhere between 15 and 50 extra calories. It’s a nice bonus, not a game-changer.
One interesting finding: men in the same study burned a slightly higher afterburn than women at the same relative intensity (about 140 calories versus 120 calories after 30 minutes at 70% effort). This likely reflects differences in body size and muscle mass rather than any fundamental metabolic difference.
How Temperature Affects Calorie Burn
Exercising in cold weather genuinely increases calorie expenditure. Your body has to generate extra heat to maintain its core temperature, a process called thermogenesis. Chilly conditions (well above freezing) can boost this heat production by up to 30%. Temperatures cold enough to make you shiver activate even more calorie-burning mechanisms.
A study tracking hikers in a National Outdoor Leadership School program found that people hiking in temperatures between 15 and 23 degrees Fahrenheit burned 34% more calories than those hiking in the mid-50s. The men in the study averaged 4,787 calories per day during winter hiking compared to 3,822 in spring. Women averaged 3,880 in winter versus 3,081 in spring. Those are total daily calories, not just exercise calories, but the difference is striking.
There’s a counterintuitive twist, though. Movement itself generates heat, which reduces the amount of extra calorie burning your body needs to do to stay warm. So vigorous exercise in cold weather warms you up enough that the cold-weather bonus shrinks. You’d actually maximize cold-related calorie burning by moving slowly in the cold, then doing your intense workout indoors. That’s not practical advice for most people, but it illustrates why the relationship between temperature and calories isn’t as straightforward as “cold equals more burn.”
Your Fitness Tracker Is Probably Wrong
If you’re relying on a smartwatch or fitness tracker to tell you how many calories you burned, take that number with a generous grain of salt. Research from Harvard’s School of Engineering found that wearable devices carry estimated error rates of 30 to 80% for calorie measurements. That means a workout your watch says burned 400 calories might have actually burned anywhere from 200 to 520 calories.
Heart rate-based estimates are better than pure accelerometer readings, but they still struggle with activities like weight training, cycling (where the wrist doesn’t move much), and high-intensity intervals where heart rate stays elevated after exertion drops. The calorie number on your screen is best treated as a rough trend indicator. If your watch consistently shows higher numbers on certain days, you’re probably working harder on those days. But don’t use it to calculate exactly how many extra calories you can eat.
Getting a Realistic Estimate
For a practical ballpark, multiply your body weight in pounds by the following rough factors per hour of exercise:
- Light effort (easy walking, gentle yoga): 2–3 calories per pound per hour
- Moderate effort (brisk walking, moderate cycling, casual swimming): 3–5 calories per pound per hour
- Vigorous effort (running, hard cycling, competitive swimming): 5–8 calories per pound per hour
A 160-pound person doing a 45-minute moderate workout lands somewhere around 360 to 480 calories. Add another 20 to 50 for the afterburn if the intensity was high, and you’re looking at a realistic total of 380 to 530 calories for that session. Most people doing a standard gym workout of 45 to 60 minutes, mixing cardio and weights, will fall in the 300 to 500 calorie range. Pushing into the 600+ range per hour requires sustained vigorous effort, like running at 7+ mph or swimming hard laps without long rest breaks.