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View Full Version : Figuring TDEE (lifting cals/BMR variances due to bodyfat)

uvawahoowa
05-10-2012, 03:38 PM
Two questions:

How would you figure/estimate calories burned while lifting?

-How would bodyfat% affect someone's calculated bmr? i.e. when you put in your info into a bmr calculator, bodfat% isn't accounted for. I would assume that someone 200lbs at 5% bodyfat would burn more calories/day than someone at 200lbs/15% bodyfat. Or is this negligible?

nobrah
05-11-2012, 05:16 AM
How would you figure/estimate calories burned while lifting?

RMR x MET is typically used to estimate the calories burned for any given activity. The problem of course, is that both RMR and MET are estimates. Your RMR could be inaccurate due to using a formula, and the intensity of lifting can vary greatly, which would affect the MET value. The most common MET values for weight lifting I've seen are 3.0, 4.5, and 6.0. 3.0 being for light/moderate intensity, 6.0 being for high intensity, and 4.5 most likely being an average.

So for example, if my RMR is 1300, I can estimate calories burned by lifting one hour at moderate intensity as (1300 / 24) x 3.0 = 163.

How would bodyfat% affect someone's calculated bmr?

Adipose tissue is metabolically active, but at a much lower rate than muscle tissue. I believe Katch put it at 6.5 calories for a pound of muscle versus 1.2 calories for a pound of fat, so a high body fat percentage will result in a lower BMR compared to someone with a lower body fat percentage at the same weight.

If you know your body fat percentage then a formula that takes it into account such as Katch-McArdle should be preferred. But keep in mind that even then a high body fat percentage can still result in overestimates.

uvawahoowa
05-11-2012, 08:47 AM
RMR x MET is typically used to estimate the calories burned for any given activity. The problem of course, is that both RMR and MET are estimates. Your RMR could be inaccurate due to using a formula, and the intensity of lifting can vary greatly, which would affect the MET value. The most common MET values for weight lifting I've seen are 3.0, 4.5, and 6.0. 3.0 being for light/moderate intensity, 6.0 being for high intensity, and 4.5 most likely being an average.

So for example, if my RMR is 1300, I can estimate calories burned by lifting one hour at moderate intensity as (1300 / 24) x 3.0 = 163.

Adipose tissue is metabolically active, but at a much lower rate than muscle tissue. I believe Katch put it at 6.5 calories for a pound of muscle versus 1.2 calories for a pound of fat, so a high body fat percentage will result in a lower BMR compared to someone with a lower body fat percentage at the same weight.

If you know your body fat percentage then a formula that takes it into account such as Katch-McArdle should be preferred. But keep in mind that even then a high body fat percentage can still result in overestimates.

Looks like great info, thanks much! I will try to apply this to my situation and see what pans out.