I received a question from one of our group bootcamp trainers and actually get this ALOT! It goes something like this..
“Hi JJ, I keep getting asked – How many calories does the bootcamp workout burn”. Can I give members the answer?”
HERE IS MY REPLY..
Yes you can.. you can make one up!
That is what all the other bootcamps do and then claim its been tested (don’t you just love this industry )
Seriously, how long is a piece of string.
Here is my reason why..
No two members will be the same.. depends largely on current fitness level (as fitness increases calories burned both during and after also increase). Due to the high EPOC training effect, more calories are burned after the activity in addition to during the exercise making it even more difficult to determine nett EE effect of the workout.
Where you see in others advertising.. this bootcamp burns X per session is garbage.. as this is not an absolute number and where one person could burn 5 Kcals per minute during and another 15 kcals per minute both are taking part in the same workout!
Imagine 2 people running on a treadmill and for this purpose they both have identical body comp.. one is running fast and the other is running slow yet they are both working at the same relative intensity its just that one cannot run as fast as the other. But both are using the same equipment (a treadmill)..
The bootcamp is like the treadmill and the intensity of the runners on the treadmill is like the ability of 2 different members intensity during the session. Lets say the fast runners energy expenditure (EE) is 2-3x more than the slow runners EE.. so to say the treadmill will burn a set amount of calories would be grossly incorrect!
Also amount of LBM determines individual energy demand as well as bodyweight (carrying a larger frame will increase energy demand however usually larger frames cannot maintain adequate intensity long enough to equal greater overall burn rate of a slimmer fitter individual).
The fitness test can determine individual est. VO2 max. From there we can estimate an individuals Kcal/min during the workout.
However, depending on the ability to maintain high anaerobic threshold intensities during the session, will determine the level of EPOC .. which may account for a large post workout EE.
Impossible to guess!!
Here’s an article I originally wrote 10 years ago explaining some of the variables..
Gives you some numbers to work with.
Basically KCals are calculated at an absolute rate of 5 Kcals per liter O2 consumed. Relative Kcals/min calculation is based on (Vo2*bwt(kgs))/200 .. note Vo2 (ml.kg.min intensity) is a major variable.
The audio I sent you also discusses the variables when trying to predict EE from exercise.
How I (Exercise Physiologists) would go about a field test for measuring relative EE (although this only measures the workout part), would be:
- test Est. Vo2 Max via fitness test
- estimate HRmax or directly measure it during test
- put a HR monitor on the subject during a session and gather mean HR (intensity)
- compute exercise metabolic profile to provide subjects HR and kcal correlations
- multiply the Kcal/min at the mean intensity (HR) by the number of minutes of the session.
Or simply guess ;).. seriously though.. I would not be happy guessing!!
So although I could get pretty close with a couple of private sessions with a member (see above) this does not allow for the EPOC and would work out rather expensive.
Your best answer is.. it is possible to estimate with some degree of accuracy a persons individual kcal’s per session by conducting a series of tests (I am able to do this). However, it is impossible to estimate a sessions output for a group. And anyone who says they can do this, is speaking form a gimmick or serious lack of knowledge and not a scientific fact. Per person yes, from a group NO.
For more on this.. this is all part of stuff I teach to Personal Trainer’s and Health Pros in Metabolic Calculations.
Keep up the good work!