Saturday, April 09, 2011

Absolute Torture


A hazard inherent in my work is that I know far too much about my body, have been tested far too many times in far too many ways, and am never happy with the results.

A few weeks ago I underwent yet another treadmill VO2max test - I think this was probably my 10th. The last time I did this, I fell above the 95th percentile for age and sex and was (mostly) happy with those results. More than the max, I was happy with the fact that my ventilatory threshold occurred at more than 80% of my VO2max. It's important to remember that the last time I was tested was two years ago, before the cancer diagnosis and beating my body into the ground with chemo. Even so...I was hugely disappointed to see that my max had dropped about 6 points compared to last time and with it, my ventilatory threshold.

None of this REALLY matters, mind you, because I'm running faster over long distances than I was back before chemo. Whether my short distance speed is still around remains to be seen (possibly next weekend), but at least in some ways I'm performing better than I used to. And apparently I'm quite the economical runner, which helps in putting more of that oxygen to good use.

Exhibit B is in progress right now. The current project for the (one!) class I'm taking this semester concerns measurement of physical activity. Easy - we're all wearing pedometers for about a week and completing 24-hour physical activity recalls every morning, for the previous day.

Now, I knew I spent a lot of time sitting. I mean, I'm a PhD student. My fingers may as well be glued to my keyboard and my rear to my desk chair. I work a full day on campus, followed often by an equivalent number of hours at home in the evening. But to actually quantify it - ugh. The torture. A sampling (the numbers in columns B-G are daily totals of time spent in each intensity, in hours):

Interesting how all the step counts end in 504, huh?

All I can say is, thank heavens I run.  Friday I didn't, clearly.  Today I ran 10 miles and I'm sitting around 20,000 steps right now.  If you estimate 2,000 steps per mile, can see how much I did the rest of the day.

There's a new area of research that has been getting a lot of attention lately - sedentary time.  Turns out that it looks like sedentary time is an independent risk factor for all the diseases we usually associate with physical activity - cardiovascular disease, diabetes, cancer, etc.  Previously it was thought that if we could just increase the amount of time people spend being active in the moderate- to vigorous- intensity ranges, we'd reduce the prevalence of those diseases.  That does work.  However, now it looks like it's not enough to meet physical activity recommendations - we also need to sit less.  So even though I meet the recommendations for weekly physical activity (far exceed, in fact), I may still be at relatively high risk of a whole host of chronic diseases precisely because I spend upwards of 10 hours a day, sitting at a desk, studying the development of these diseases.

Oh the cruel, cruel irony.

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