Calculate calories burned from lifting weights?

[enanthate]

Hi all,

So I was thinking about how you could calculate the calories burned when lifting weights. The actual energy requirement should be simple enough if I'm not mistaken :

Amount of weight in kg * distance traveled per repetition in m * g constant * number of reps = Joule expenditure

Then take this and divide it by 8-26% efficiency for human muscle.

Does this sound right for a simple, general caloric requirement calculation or am I missing something I should be taking into account

Thanks for any input

 

[enanthate]

I meant18-26%

Hi all,

So I was thinking about how you could calculate the calories burned when lifting weights. The actual energy requirement should be simple enough if I'm not mistaken :

Amount of weight in kg * distance traveled per repetition in m * g constant * number of reps = Joule expenditure

Then take this and divide it by 8-26% efficiency for human muscle.

Does this sound right for a simple, general caloric requirement calculation or am I missing something I should be taking into account

Thanks for any input

 

[ZapperZ]

1. You need to be aware that the "calories" used in categorizing the amount of "energy" in food and in body functions is actually "kcal" in mechanics.

2. Even when the weight is not moving, by holding it up, you are still burning calories, since the muscles have to contract and uses up energy. Yet, mechanically, this does no work.

3. Similarly, on the downstroke of weight lifting, depending on how slow the weight is moved, energy is still burnt by the muscles, even if mechanically, work is done by the gravitational field.

I'm sure physiotherapists have ways of estimating this, but what you did appeared to be too simplistic and not take into account a lot of other significant factors.

Zz.

 

[enanthate]

I agree that it is very simplistic. But that's what I'm looking for :) just want to make sure my thinking is right. In any case this calculation will be on the low side for the reasons you mention

1. You need to be aware that the "calories" used in categorizing the amount of "energy" in food and in body functions is actually "kcal" in mechanics.

2. Even when the weight is not moving, by holding it up, you are still burning calories, since the muscles have to contract and uses up energy. Yet, mechanically, this does no work.

3. Similarly, on the downstroke of weight lifting, depending on how slow the weight is moved, energy is still burnt by the muscles, even if mechanically, work is done by the gravitational field.

I'm sure physiotherapists have ways of estimating this, but what you did appeared to be too simplistic and not take into account a lot of other significant factors.

Zz.

1. You need to be aware that the "calories" used in categorizing the amount of "energy" in food and in body functions is actually "kcal" in mechanics.

2. Even when the weight is not moving, by holding it up, you are still burning calories, since the muscles have to contract and uses up energy. Yet, mechanically, this does no work.

3. Similarly, on the downstroke of weight lifting, depending on how slow the weight is moved, energy is still burnt by the muscles, even if mechanically, work is done by the gravitational field.

I'm sure physiotherapists have ways of estimating this, but what you did appeared to be too simplistic and not take into account a lot of other significant factors.

Zz.

 

[cfp363]

Is your 18-24% efficiency just for the muscles moving the weight? And this is for anyone, because I've had the same question as enanthate above, and maybe there is just no way to figure it out...but how do you calculate as a percentage of a 1RM or even vs your body weight.
I guess I'm asking the efficiency in which someone moves a specific weight. Example 20 squats at 50lb for a 200lb man vs a 100lb man, assuming everything else is the same. From a mechanical standpoint the 50lb weight requires the same amount of energy to move it for each person, but in reality does the 200lb man actually burn less calories since it's a smaller percentage of his body weight, ie he's more efficient?