Saunas for weight loss

[taekwondave]

you would not be a good fitness coach

Was I not being sensitive enough?

Look, it was the calories in, calories out notion that I learned from THIS forum that got me thinking about this. Serious question: how do they determine how many calories all of these different exercises burn? I guess that is what I don't understand. When they say that running burns more calories than rowing, how did they measure that? How can you even compare those two activities? It seems disingenuous to say that running burns "more" than say...cycling, when you are really comparing apples to oranges, aren't you? I mean, how do you determine the equivalent MPH of cycling to running if not by heart rate? Obviously cycling at 10 mph isn't going to burn as many calories as running at 10 mph because it's MUCH HARDER to run at 10 mph than to cycle. But how do you say that someone who is running at 7 mph and whose heart rate from so doing is at 135 beats per minute is burning more calories than somebody who is cycling at...30 mph and whose heart rate from so doing is at 135 beats per minute as well? How did they come up with this stuff?

If you can answer me that question then I think I'll understand why sauna/steam room sitting are not viable methods of fat loss.

[taekwondave]

Here. Someone check this site out and tell me what's wrong with it.

http://www.braydenwm.com/calburn.htm

Here he shows the connection between heart rate and calorie burning. If they aren't using heart rate to determine calories burned during an exercise, then what are they using?

He used this site to come up with the formula he uses I believe:

http://www.braydenwm.com/cal_vs_hr_ref_paper.pdf

[woot]

While it's true that exercise is going to burn way more calories than a similar amount of time spent in a sauna, I think the generally-held opinion that weight loss/gain can be reduced to calories consumed vs. calories burned (=basal metabolic rate + exercise) is extremely naive. Granted, the laws of thermodynamics apply to weight loss, but they apply to everything else too. Why is weight loss almost always treated like a physics problem, when it is so obviously a biology problem? Do we really feel comfortable treating the human body like a simple container that stores calories according to two simple factors?

I have written a lot about this and could write a lot more, but my understanding of these issues suggest that there are a huge number of factors that can play significant roles in body fat levels. Thermoregulation is definitely one of them. Sitting in a sauna doesn't seem particularly productive, but there is simply no doubt that you are burning more calories doing that than sitting on your couch at home, just as there is no doubt that you're burning more calories swimming in 50-degree water than 70-degree water.

[Joe Public]

My understanding has always been as follows. When exercising, our bodies use stored energy to produce the ATP that is required for muscle movement. The amount of muscles used, the intensity level, and the duration of exercise affect the amount of energy used. Also, the heart rate increases when exercising to, among other things, carry oxygen and sugars to the muscle tissues.

A hot environment (somewhere above 98.6F) triggers an elevated heart rate, too. However, the body is using the circulatory system like a radiator to try to get back down to normal temperature. The body pumps as much blood along its surface as it can as quickly as it can to try and cool itself. The increased sweat production is due to the same cause. The energy required to speed the heart is insignificant compared to the energy used by muscles during exercise.

I have so specialized training in this area, so fire away.

[NorthwestUteFan]

jay santos,
You are wise to trust your instinct.

Woot,
Physics is of a course a simplistic way to look at the issue. I used a physical system as an allegory simply because biological systems are extraordinarily complex, leaving the OP to determine the moral of the story. I work on one of the most sophisticated pieces of machinery ever built and it is small potatoes compared to a simple amoeba.

However I am an engineer and look at everything as an energy balance problem.

TKDave,

My point with the allegory of the parked car vs the moving car was to illustrate the weakness of using heart rate (the tachometer) as an indication of work output. With the car in park and the engine at 3000, the cooling system will be taxed more than it would if the car is moving. However the only energy being used is going to turn the engine and pump the cooling fluid. When the car is traveling up a hill with the engine at 3000 rpm, the cooling system is far more effective and thus does not require as much power, but the actual work of moving the mass of the car up the hill requires at a hundred times more energy than simply turning the engine and circulating coolant.

The true method to determine the work output of a cars engine would take into account the rate of flow of air and fuel, measure the makeup of the exhaust gas, and also measure the rate at which the engine can turn a dynamometer (or move a vehicle of a known mass).

Likewise the best indicator of how much work output of your body would be to measure the flow rate of respiration, determine the O2 and CO2 content of the intake air and compare it to the exhaled air, and also measure the work accomplished by running on a treadmill or pedaling an exercise bike under controlled set of parameters. This gives us the body's actual rate of oxygen usage, from which we can determine how difficult is the work being performed as well as determine the body's efficiency at processing oxygen (and thus 'fuel' - ATP) into work. Google "VO2max" for more info.

More to the point, which requires the most work: standing next to your car in the driveway or pushing it up a hill?

You will not see a very large increase in work expended by sitting in a sauna vs sitting on a couch in your living room. Yes, you will burn more calories but it will not approach the calorie burn rate if you exercise to get the same heart rate.

[taekwondave]

Hm. Well, you all SOUND smart. And I know I'm not getting my info from anywhere credible. I really am just trying to reason my way through it with what I THINK I know. So you may be right.

I got it. How about I do a little experiment: I am male, 27 years old, 170 lbs, 5' 10" tall. My BMR is approximately 1830.5 and my RMR is approximately 1770 or so. I have a calorie counter on my phone that I have been using lately. It's been great. What if I eat my BMR or RMR every day, nearly to the calorie and the only "exercise" I do will be sitting in the steam room at Gold's Gym every day, thirty minutes per day, for two weeks...nah, that wouldn't work. Cause if I don't lift any weights for two weeks then my muscles would probably start to shrink and any fat I might lose might not be accurately reflected in my body fat %.

Doesn't SOMEBODY have a study on this???? Woot, I would think you could find something. You seem like an academic baller.

[woot]

Doesn't SOMEBODY have a study on this???? Woot, I would think you could find something. You seem like an academic baller.

The stuff I've read tends to deal with cold exposure, in the context of either thermoregulation or the activation of brown fat stores. There's a pretty good body of literature on those topics, although the existence of brown fat stores in (at least some) adults is a relatively new discovery. I'm not familiar with any sauna/heat exposure literature. While the moisture in the air would cause the body to work harder than it would in dry heat due to water being more conductive than air (same principle as swimming burning more calories than a similarly intense running workout), I still don't know how significant it would be in calorie burning.

I'm pretty sure I posted some cold exposure links on CUF at some point; I'm not feeling keen on looking them up at the moment. I should also insert the usual caveat about my expertise lying in other areas and this stuff being more of a hobby for me.

[Babs]

Doesn't SOMEBODY have a study on this????

How much is it worth to you?