How many calories can you burn through exercise?
The short answer is not NEARLY as many as you think.
Cardiovascular activities, on average, burn about 10 calories per minute. A beginner with a very low level of fitness and poor work capacity will burn less. A trained individual can withstand intensities which will burn more (up to 20 calories/minute). But, let's call it 10 calories per minute on average. Weight training burns roughly 7-9 calories per minute. I should note that there is huge variability here. The type of exercise you are performing (multiple joint vs. single joint), the loads you are using (high percentage of repetition maximum vs. low percentage of repetition maximum), the overall volume of the workout, your momentary effort level on each exercise, etc. all will influence how many calories are burned.
Also, keep in mind, strength training workouts are basically interval workouts: you do a set, rest a minute or so, do another set, etc. So, while you may be in the gym for an hour when you strength train, probably only 30-40 minutes of that is actual metabolic work. Ok, so let's say you were to exercise 7 days/week for an hour: 3 strength workouts (maybe Mon/Wed/Fri) and 4 cardio type workouts (Tues/Thurs/Sat/Sun).
Let's assume the strength workouts, on average, burn 7 calories/minute and you are performing actual work for 40 of those 60 minutes (this is generous). Let's also assume you are doing 60 minutes of continuous calorie burning work at an average of 10 calories/minute on cardio days. Again, this is generous. So...
3 strength training workouts: 120 minutes of work @ 7 calories/minute=840 total calories burned
4 cardio workouts: 240 minutes of work @ 10 calories/minute=2400 total calories burned
Grand Total for the Week: 3240 calories Pretty shocking huh?
Most people who exercise assume they are burning thousands upon thousands of calories. The reality is it's not all that much. 3240 calories is less than 1 pound of fat (3500 calories roughly). This is why people who don't change their eating habits (which doesn't require any actual time I might add) and try to "exercise off" body fat fail miserably, become discouraged, and say "screw it".
Here is some more food for thought...
What percentage of the population actually exercises 7 days/week for an hour??? Have you seen the statistics on physical activity in the U. S.???? Most people get 1/4 to 1/2 of this amount...and I'd say these people are probably in the top 25%.
It can take up to 6 hours-based on the calculations above-to burn 3240 calories. How long does it take to eat an extra 3240 calories each week? How long does it take NOT to eat 3240 calories each week?
Before I get a lot of people ranting and raving about EPOC, the "after burn" from workouts, etc. let me just say that all of that stuff is drastically over-stated and misinterpreted. If you look at the research on post workout calorie burn and metabolic rate elevation, it's not significant enough to even be considered. I'll be generous and give you an extra 10% (based on what most research has shown). So, someone doing a mix of strength and cardio 7 days per week for an hour each workout might burn an extra 300-400 calories for the week. Wow. You’ll be shredded by 2023.
So now that I’ve given you a reasonable answer to the question of how many calories can you burn through exercise, let me present a little table showing how this equates to fat and weight loss:
The Bottom Line
Your nutrition compliance will be the primary driver of fat loss. Stop focusing on how many calories you are or, more likely, are not burning through exercise. It’s hardly worth considering.
Strength train and do cardiovascular work to increase strength, retain and build lean muscle mass, improve work capacity, and to improve overall health.