Thursday, October 14, 2010

"What is the Maximum Amount of Calories I can Burn in a Week Through Exercise?"

I received the following question from a blog reader, and I thought it-and my response-would make for a good post.

PJ Striet

PJ:


I have a spurt of motivation and I'm really trying to drop weight so I can look great for the holidays. Here is a question I have: realistically, what is the maximum amount of calories I can burn on a weekly basis if I were to exercise every day? Thanks!


Justin from San Diego, CA

Great question...and I think the answer may surprise you. Instead of making a lot of work for myself-and because I can't summarize it any better-go read THIS POST & THIS POST from Lyle McDonald. He lays it all out for you.

For those of you who chose not to read the two posts linked to above, here is the "Mel Brooks Short Short Version":

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, as Lyle did in the posts linked to above, 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...beyond planning) and try to "exercise off" body fat fail miserably, become discouraged, and say "screw it". Here is some more food for thought...

  1. 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%.
  2. 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 emailing me 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.

Here is a table (which is even more depressing) which Lyle McDonald presented in the posts I linked to above:

Calorie Burn Duration Burn/Workout 3X/Week Estimated Fat Loss 6X/Week Estimated Fat Loss
5 cal/min 30 minutes 150 calories 450 calories 0.128 pounds 900 calories 0.25 pounds
5 cal/min 60 minutes 300 calories 900 calories 0.25 pounds 1800 calories 0.51 pounds
10 cal/min 30 minutes 300 calories 900 calories 0.25 pounds 1800 calories 0.51 pounds
10 cal/min 60 minutes 600 calories 1800 calories 0.51 pounds 3600 calories 1.1 pounds


I'm going to leave you to reflect on this information, and then I'll come back next week and talk about this stuff some more. Have a good remainder of  the week and weekend.

http://www.personaltrainerscincinnati.com

5 comments:

Bret Contreras said...

Great Read PJ!!!!!!!

Mark said...
This comment has been removed by the author.
Mark Young said...

Fan-frigging-tastic

I think anyone and everyone trying to exercise to lose weight should read this.

Great stuff PJ!

http://www.markyoungtrainingsystems.com

Revive Fitness Systems said...

Thanks Mark! I really enjoy your insights as well.

Unknown said...

hi i see this is very old! hopefully someone can answer my question! i know how to add up calories iv burnt myself.. i want to know how many calories is it safe to burn per week! my tdee is 3000 i currently burn around 600-700 per day and usually have a calorie net deficit of around 5-800! how low can i go safely and how many calories is safe to burn per week/day! obviously if you choose to u could burn 3000 a day! but that im among wouldn't be safe! how far can you push deficit and burn safely roughly?

thanks
Chris