After abandoning my Fitbit device in January because using it didn’t see improvement in my weight (see previous post), I was wondering if I could still measure my risk to develop cardiovascular diseases and other preventable chronic diseases (diabetes e.g.). So, still sitting at my desk (something I do for more than 8 hours a day in theory – probably more in practice), I looked into the ways to monitor my risk for these diseases …
But first, it is well known that the lack of physical activity is detrimental to health. And it was demonstrated to be (at least partially) responsible for preventable chronic diseases like heart disease, stroke, cancer and diabetes in the occidental part of the world (see this previous post or this one e.g.). I found this paper from Booth, Roberts and Laye in 2012 very interesting (“Lack of exercise is a major cause of chronic diseases” in Comprehensive Physiology ; the US National Library of Medicine has the author manuscript in free access). The paper is a good summary of what activity and inactivity are, their consequences, tests used to benchmark activity and inactivity-related diseases. It’s a bit long but easy to read and full of references to explore further.
From there, besides blood tests, it appears VO2 max is really the only gold-standard to measure cardiorespiratory fitness – and this only one of the many faces of physical activity. However, measuring VO2 max requires a treadmill and equipment (see picture below). Therefore acceptable proxies were developed, like the length of time running or cycling in standardized tests (see references 65 and 263 in Booth et al. paper).
To measure cardiovascular risk, numerous tests exist, even online (see here, here or here e.g.). These tests include behavioral questions (eating habits, smoking habits, inherited risk factors, …). But they also rely on measures of, a.o., blood pressure, cholesterol, some proteins. These tests are usually performed by doctors or biomedical laboratories at the request of doctors. They are usually difficult to perform routinely at home (especially if you are not affected by diabetes, for instance, and you don’t need to perform them for other reasons than prevention itself).
So, in the end, counting the number of steps or timing the duration of daily physical activity are the easiest ways to monitor – not the risk of sedentary-lifestyle-related disease itself but to monitor – compliance with primary prevention of these diseases.
What is also interesting in the aforementioned paper by Booth and colleagues is that it contains a table of the estimated number of daily steps and this number is declining since prehistorical times!
In 2016, my mean daily number of steps was only 6998 steps (see figure below), far from the recommended 10000 daily steps. This appears to be pretty constant over the year. And unfortunately, it appears to be similar to what I did in 2013.
Given this, I decided to charge my Fitbit tonight and to use it starting tomorrow. Not to loose weight (per se, it doesn’t work ; although I’m still hoping it will be a positive side effect of this). Not to measure my cardiovascular risk (see above, this is not a direct measure). But to measure my primary prevention of sedentary-lifestyle-related diseases (trying >= 10000 steps and >= 30 minutes walk every day).
Photo credit: “running away and going no where” by salem elizabeth on Flickr (CC-by-c-nd)
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