What’s it got to do with movement?
This post is the first in a two-part series aimed at looking at the true cost of inactivity in the UK in number of lives lost. Why, this being a transport based blog? Well, I believe that there is strong evidence that the built environment has a direct effect on peoples health. We know that exercise is well correlated with lower mortality rates (e.g. meta-analysis (review of research done) here). In fact, we see that the least fit 25% have mortality rates have four times that of the most fit 25%. We see this pattern over and over again. We also know that the number one cause of people not exercising is that people feel that they do not have time to exercise. The answer, to me, seems to be that we need to help people fit more exercise into their day in time where they would otherwise be sedentary. This could include more movement at work for some; but with people spending an average of 1 hour every day travelling, I argue that commute/travel time is the obvious candidate for fitting in more exercise. Often, journeys could be moved at least partly to active travel modes with either a trivial increase in travel time, or often, a reduction in travel times once the quickest route has been worked out, some fitness has been gained and most appropriate equipment sourced. There is strong evidence from Denmark that cycling to work reduces mortality (your chance of dying in any given year) by 28% once other factors (diet, economic group, other physical activity) are adjusted for (from this study here).
How does exercise save lives?
Well, we know it prevents heart disease, reduces levels of certain types of cancer; this is a matter of scientific record. But I think it goes further than that. I would suggest that being fit, which leads on from exercising, has many other benefits when it comes to staying alive. Sure, more cycling might increase your chance of being involved in an accident by some small measure over sitting in a train or driving for the same length journey, but it seems reasonable to suggest that your chances of surviving an accident as a fit person are significantly higher – you can control a fall better, and your better developed musculature, tendons and bone structure will help reduce your chances of death in the event of an accident. Suicide is the main cause of death amongst 5-34 year olds, and there’s some evidence that physical activity helps fight the depression that leads to it.
What if you still have a fall, a heart attack, or cancer? Well, my opinion (as distinct from direct scientific research that I can access) is this. The thing that finally kills you is you no longer being able to pump oxygenated blood round your body. If you are fit you have more blood, bigger usable lung area, a bigger heart, and better developed blood vessels, then when the crisis comes you can stay alive for longer, giving your body a longer window to sort out the problem, or the magic of modern medicine longer to save you. Even things as small as doctors being able to take blood samples to find out more about what’s making you ill – because you have bigger veins from exercising more (established long enough that it’s hard to find the studies online, but e.g. here: http://www.ncbi.nlm.nih.gov/pubmed/12640286) – can be expected to be significant (is significant, according to doctors that I’ve spoken to).
Beyond the death toll..
There is also the reduction in quality of life that comes with being less fit: regular exercise cuts the risk of dementia in old age by nearly 2/3; reduces the effects of type 2 diabetes and the chances of being affected by it in the first place by over 50%; there even more immediate short term effects, with reduction in obesity, most obviously, but also brings benefits as wide as increases in intelligence (certainly in children).
The scale of the problem
This all sounds very serious what with all this talk of death, dementia, and diabetes; but I don’t see it that way – I see a massive opportunity to give many people longer, more productive lives with less ill health and disability. In part two of this blog I will explain why I think that it is possible that as many as A THIRD of all deaths in the UK – nearly 200,000 deaths per year – may be premature deaths which exercise would prevent. Many of these deaths could be prevented by clever urban design which gives people the opportunity to exercise on a daily basis. This is higher than previous analysis that I’ve found, but I think I have a strong case that is worth considering.