Seriously, is that the real reason why so many people on here are so keen on immersing themselves in icy water?
My impression, based on a loose awareness of thermodynamics and concepts like shivering thermogenesis, is that the answer is "yes, but not enough to justify the discomfort involved" - but I've never seen any figures or equations to back this up. Can anyone here enlighten me?
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(Psst, V-rap, I'm trying to be sensible now - I'm not sure how long I can hold on though).
the below was stuck on the wall of the physics dept. at college:
Beer and Ice Cream Diet
As we all know, it takes 1 calorie to heat 1 gram of water 1 degree centigrade. Translated into meaningful terms, this means that if you eat a very cold dessert (generally consisting of water in large part), the natural processes which raise the consumed dessert to body temperature during the digestive cycle literally sucks the calories out of the only available source, your body fat.
For example, a dessert served and eaten at near 0 degrees C (32.2 deg.F) will in a short time be raised to the normal body temperature of 37 degrees C (98.6 deg. F). For each gram of dessert eaten, that process takes approximately 37 calories as stated above. The average dessert portion is 6 oz, or 168 grams. Therefore, by operation of thermodynamic law, 6,216 calories (1 cal./gm/deg. x 37 deg. x 168 gms) are extracted from body fat as the dessert's temperature is normalized.
Allowing for the 1,200 latent calories in the dessert, the net calorie loss is approximately 5,000 calories. Obviously, the more cold dessert you eat,the better off you are and the faster you will lose weight, if that is your goal.
This process works equally well when drinking very cold beer in frosted glasses. Each ounce of beer contains 16 latent calories, but extracts 1,036 calories (6,216 cal. per 6 oz. portion) in the temperature normalizing process. Thus the net calorie loss per ounce of beer is 1,020 calories. It doesn't take a rocket scientist to calculate that 12, 240 calories (12 oz. x 1,020 cal./oz.) are extracted from the body in the process of drinking a can of beer.
Frozen desserts, e.g., ice cream, are even more beneficial, since it takes 83 cal./gm to melt them (i.e., raise them to 0 deg. C) and an additional 37 cal./gm to further raise them to body temperature. The results here are really remarkable, and it beats running hands down.
Unfortunately, for those who eat pizza as an excuse to drink beer, pizza (loaded with latent calories and served above body temperature) induces an opposite effect. But, thankfully, as the astute reader should have already reasoned, the obvious solution is to drink a lot of beer with pizza and follow up immediately with large bowls of ice cream.
We could all be thin if we were to adhere religiously to a pizza, beer, and ice cream diet.
Happy eating!
The quicker you can get yourself cool, then the less effort your body needs to make to get it back to normal.
Therefore cool baths are good.
And hot baths arent as you feel really woozy coming out of them, and then need to go for a lie down. But its quite good fun.
I do actually know someone who only managed to lose the last couple of pounds on her diet after switching jobs from bakery to deli counter in Morrisons. She attributed it to the change in temperature rather than the greater distance between her and the donuts.
I use hot showers to prevent and relieve muscle aches, but dinosaurs are different ;o)
So I think the cold bath thing would use more calories, assuming that your body had time to adjust and start generating more body heat.(?)
Personally I will give it a miss!
No, that doesn't work, how about E=mb^2...
Nope, nothing there, let's try E=mc^2, hmmmmm, now we are getting somewhere.
where's it going to get the heat from? It's a biological thing but I'd guess as a by-product of cellular respiration - i.e. burning whatever fuel was around
I guess it changes depending on where your cold water tank is and what time of year it is, but I'd be surprised if it where less than 10 degrees C. Apparently a bath holds 65-80 litres when completely full (so only half full for a cold bath?) and room temp of a bathroom is around 22-23 degrees. I'm also pretty sure that in if you stayed in it for around 10 minutes that the temperature only rises a couple of degrees rather than fully up to room temp. So we are talking raising around 30 to 40 litres (30,000 to 40,000g) of water by only a couple of degrees . One calorie (0.001 kcal) raises one gram of water one degree C
So, that equals 30 to 40 kcal per degree of raised temperature. I seem to remeber that the human body produces around 25-30 kcal per hour of radiated heat in a ambient room (though I could be making this bit up).
so the answer is , it probably makes bugger all difference. And none of the above takes into account that the water will be heated by the air temp and absorb heat through the sides of the bath etc.
Anyway, cold baths make my willy small.
No sir, I certainly do not.
1 calorie (imperial measurement) raises the temperature of 1 ounce of water through 1 degree farenheit.
1 Joule (SI measure) raises the temperature of 1 gramme of water through one degree centigrade.
I don't know the answer to the question, but your body will react in two different ways surely? Cold water, blood vessels to extremities constrict to reduce heat loss. Warm water = vasodilation and body having to work harder (=sweating?) to try to prevent overheating.