One of the experiments I was a guinea-pig for on the space station was a study into the correlation of heart rate and metabolism (energy expenditure) in space.
I didn’t have to do much – drink some amazingly expensive water (isotopically distinctive so it would make a good marker) and keep track of everything I ate. And wear a heart monitor, which recorded every beat for much of the flight. Apart from the irritation associated with the wiring of the heart monitor it was straightforward, all the hard work was done on the ground at the Sports Science Institute of South Africa, at UCT.
This was an extension of research they had been doing into the correlation of heart rate and metabolic activity in athletes, and they wanted to see if the same rules apply to astronauts in flight. Conclusions:
- Yes, they do.
- Astronauts don’t burn a lot of energy in space. Floating around is the ultimate couch potato profession, except for interesting events like EVA’s and decompression scenarios where every movement is against the pressurization of your suit.
I was reminded of all of this yesterday when I took a look at the readings of my heart rate monitor – just a low-end Polar heart strap and watch that I’ve been wearing out on the slopes for interest’s sake. The dear thing thinks I’ve been doing AMAZING amounts of exercise while snowboarding. In one day, apparently, I burned off 6,000 kcal, which is hardly likely given my very relaxed (“Sunday tripper”) approach to exercise in general.
I think the issue is that my heart rate is generally elevated when at altitude. The watch doesn’t know anything about altitude, though, so it thinks that I’m tearing up some imaginary track when really I’m enjoying a cup of vin chaud * at 3,000m.
So, does anybody know how to recalibrate one of these things, for a more realistic result? I’m guessing somebody has a data set which would allow one to normalize heart rate for altitude and body mass, and get better results. Or is there a monitor out there which senses altitude and takes it into account automatically?
* thanks to Pierre for pointing out that I’m not, in fact, drinking “lime wine”. What a limey I am.