[thedoc (OP)]

Bjoern Brembs  asked the Naked Scientists:
   
Thanks for a great show. I usually listen to you when I prepare my experiments, which is a boring manual labor task: I glue fruit flies to little hooks:

Anyway, the other day you first talked about how inexperienced scuba divers use much more air then experienced divers and right afterwards you discussed the question if you could slim down just by drinking cold water. Friends of mine (a couple) are scuba divers. Every spring
they go scuba diving in cold water - their motto: freeze yourself slim. They protect themselves against dangerous cooling, of course, but keeping the body at normal temp as well as the exercise of diving burns enough calories to get the waistline perfect for summer beach time :-)
So while cold water taken orally may not shed any pounds, external application may work :-)

Keep up the great show!

Bjoern

What do you think?

[chris]

The average adult may devote as much as 30% of their daily calorie burn to keeping warm. Any environment that saps heat from the body provokes a compensatory increase in metabolic rate to maintain core body temperature.

So scuba diving - or any sort of immersion - in cold water will, over and above the metabolic demands imposed by the exercise itself, cause metabolic rate to rise to compensate. This will burn calories. If they are not replaced then you will lose weight.

This is an interview we did a few years ago on the physiology of cold immersion.

We also looked at what happened when one of our own staff, Graihagh Jackson, took a cold dip...