Commuter cycling: does it help your health?

In an earlier post I explained that recently I have been making more individual cycling trips than at any point in the last thirty-odd years. I also commented, when comparing the subjective experiences of cycling and walking, that cycling offers a wider range of physical intensity.

Even though most of my recent cycle trips have been short distances ( < 5 miles) it has been very striking that even a short, slow, flat, offroad journey will involve bursts of energy that you simply do not get in a walking trip. This is partly because nowhere, nowhere is completely flat. But you don’t really remember it. Thirty yards up a bit of slope, enough to make you pant for a few seconds? Forgotten as soon as its over. Accelerating to get past a bus? You do it without thinking or bothering. And these events occur even in the trips of the gentlest, the slowest, the most pootlesome of bike riders.

This struck me as something where – viewed purely as everyday transport – cycling really does win over walking. Raising physical intensity in a walking trip is difficult. With effort, you can just about make walking as hard as a rather gentle bike ride. I had lately taken to breaking into a minimalist jog for parts of walking journeys and of course Bristol is famously hilly – but I’m both temperamentally impatient and interested in experimenting with this kind of thing and I have to admit that truly vigorous utility walking is never going to be that popular.

So I was very pleased to see my speculation confirmed at Commuter cycling: does it help your health? a talk by Professor Ashley Cooper [note, I’ll change the link to the actual powerpoints, once they’re up on the Bristol Uni website]. The talk was one of the events of the Bristol Cycle Festival

There is now a ton of evidence about the benefits of what has been given the jargon term “moderate to vigorous physical activity” and Prof Cooper sketched out some of the seminal studies (the London bus crews for instance – conductors and drivers provided a really neat pair of otherwise similar groups which differ consistently in their workplace levels of physical activity). However he went on to say that there is “little hard evidence” of the specific benefits of cycling – but there is some. (By “hard” he meant well-designed academic studies – there is of course masses of personal experience – anecdotal evidence is not necessarily trivial in the sense that it can point at a real phenomenon, but the proper studies do have to be done to test our intuitions).

Sorry, I’m digressing – I made fairly extensive notes and I don’t wish to just transcribe them. To get back to the point I started with, Professor Cooper said plainly that the available evidence shows that:

“cycling gives you a bigger bang for your buck in terms of health benefits [than walking]”

And that benefit is thought to be because of the higher overall intensity of cycling:

“it is intensity which gives you the health benefits”

The research into physical activity has always shown that intensity is important. “Intensity” (how much it raises your heart rate) is to be counterpoised to “duration” and the current thinking is moving towards saying that “high intensity + short duration” is better than “low intensity + long duration”. I see that my notes contain the line “for increases in life expectancy – duration does not matter”.

Not sure how accurate that note is – it does sound pretty radical. It’s interesting to me how knowledge about exercise and health has changed over the years. At one point it seemed to be thought that beneficial exercise had to be both quite intense and of fairly lengthy duration. Decades ago I recall being told that going for a five- or ten-minute run couldn’t possibly do me any good at all – and as for walking hah! Well I’ve gradually watched the advice change and now it seems that almost any exercise at all will do you some good. This is great news. (And, incidentally, a nice example of the way the way that science changes its picture of the world as more evidence comes in). Any exercise will do you some good, but (in a broad way) greater intensity gives better results.

A complication

My earlier post on the epidemic of sloth was just a little disingenuous because I omitted an important caveat. The report I referred to was clear that physical activity wasn’t quite the whole story. The other half of the picture is the amount of sedentary time – if moving is a plus then sitting is a minus. You could take a good dose of exercise and then wipe out the benefit by sitting at a desk for the rest of the day. This was completely new to me; Prof Cooper said that it is new to everyone because the conclusions are recent.

The importance of decreasing the amount of time you spend sitting inertly on your bum is yet another plus for cycling – a “double hit” in Prof Cooper’s words – because the time on the bike is time spent not lazing about. You might be sitting on a saddle but you are active. It’s an even bigger plus for walking because walking journeys take so long (I’m currently at the stage where I arrive half an hour early for everything because I’m still applying walking calculations and can’t quite believe how much faster the bike is).

This caveat about taking care not to sit around for most of the day is important. The finding that, on the whole, intensity is more important than duration can be easily misrepresented. The BBC Horizon documentary the truth about exercise (the full versions on youtube have unfortunately been taken down) did not exactly misrepresent things and it did spend plenty of time discussing the importance of non-sedentariness but the documentary gave a misleading overall impression. Nevertheless it was good enough to be worth looking out for repeats, if you haven’t already seen it.

The structure of the documentary resulted in a foregrounding of some research findings about capsule exercise. The findings are that it is possible to get the full benefits of exercise from a very small amount of maximum intensity exercise. In the documentary we see the presenter (the very affable, and medically trained, Michael Mosley) following a programme where he does three twenty-second intervals on an exercise bike. The idea is that you really have to go absolutely flat out – you need to be gasping and groaning at the end – but you only need do this minute’s-worth three times a week. This is quite staggering I’d agree. Unfortunately the documentary did not make it clear enough that this needs to be done in conjunction with reducing the amount of the sitting down. The programme was not structured in such a way that the central argument about exercise came through. Although all the pieces were in place it succumbed to the gosh-wow factor (perhaps from a sad lack of confidence in the mental acuity of its audience?) and this resulted in a degree of confusion. (Horizon seems to do this rather a lot).

Incidentally Prof Cooper remarked that when he presents to audiences of fellow academics and practitioners in the area of physical activity, there are always a bunch of people at the back who have deliberately chosen to stand rather than sit. That seems perhaps a little ostentatious to me, but in case you’re wondering, I’m writing this post standing at my desk, with the laptop perched on a bunch of boxfiles and I’ve been doing part of my desk work this way for a few months now.

Finally

This all seems plain enough to me. If you get to work on a bike you get some reasonably intense exercise every week day. Furthermore, the time it takes to get to work is not time spent immobile in a chair. Double hit.

This knowledge is not a big secret. “The government has been told about this. It does know … it’s up to them to do something about it” said Prof Cooper. We’ve been so battered by half-baked US rhetoric about “big government” that perhaps it needs spelling out: the government spends my taxes to do things that I cannot do on my own by means of my own individual choices. I damn well want my taxes to purchase public health by means of doing what is necessary to foster walking and cycling. Increased public health means an increase in the amount of choice you have in your individual pursuit of satisfaction. It leads to more freedom.

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Political will in Bristol

I’ve already mentioned the Bristol Cycling Manifesto, but here it is again.

The top line is that there is a petition that, if you live in Bristol and wish to do anything other than use a car for every single journey, you really should sign.

This is about political will, as (briefly) discussed yesterday. We’ve ended up with a mayor who seems to genuinely support cycling. (And George Ferguson seems to have more of a real clue about it than Boris Johnson did). Making the changes that will foster active travel is going to come up against both considerable inertia and active opposition. It can only be done if there is seen to be real support. From the numbers of people riding bikes around Bris that support is definitely there – but it needs to be seen to be there.

As well as the petition, Bristol Cycling Campaign’s freedom to ride campaign includes a framework for the infrastructure layout that would make the city easy to bike around. Here’s their cute map of what a decent Bristol cycling network ought to look like:

toptube map print version june2013

This is another way that political will can be created – you do some of the work that ought to have been done already by salaried planners, you show what things ought to be, roughly, like. You act as if the thing has already started by providing a starting point.

Did I say that I really admire people who can get this sort of thing going? I am really not an activist, I’m more of a sit-on-my-bum-and-thinkivist.

Political will

“We could do what the Netherlands did – if we had the political will”. I’ve said this kind of thing myself – and what I’ve meant is that there is nothing inevitable about our present personal transport mess, that things could have been different if different planning choices had been made, that things could well be better – if different planning choices were to be made now.

But what is this mysterious thing, “political will”? What actually causes the people who have the choice-making power to do the right thing? What makes elected politicians feel that something is “the right thing”? What heartens them to actually push things through?

I don’t subscribe to the “all politicians are scoundrels” view. I think they are in many ways like the rest of us except that they enjoy the strange game of “politics”. What I mean by this is that politicians want to be not just re-elected (so they can go on playing the game) but also to be liked and respected and to feel they have been of some use – all the things that most of us want. But (also like most of us) they usually need to be pushed into doing awkward or difficult things. So “the right thing” needs to be made easier for them.

Which is all a roundabout way of mentioning the “get Britain cycling” epetition. I’m rather sceptical about petitions, but it can’t do any harm?

Almost certainly, everyone who sees this blog has already signed, but I thought you might like to see how it’s doing. It was started in April and will stay open for one year. The idea is that it will be taken a little bit seriously if it gets to 100,000 signatures. I’ve been tracking it since the start of May and this is how it’s gone so far:

e-petition_June

Will it get to 100,000? Hmmm. Not impossible, but not by any means inevitable. I’ll give another update at the end of July.

Of course generating “political will” might be an easier task at the local level …

“Mental infrastructure”

I like to coin new and useful phrases. I’ve been using this term in my own thinking about active transport and reading Dave Horton’s most recent post I think it’s time to float it into the wider world.

The right sort of physical infrastructure is essential for a less car-centric world – as with so many things, exhortation is not enough, nor even leading-by-example.

On the other hand, exhortation – in it’s more refined form of intelligent communication – is not at all trivial. Leading-by-example is even less trivial because it indicates to the onlooker that you take this seriously, you mean what you say. Walking the talk is in fact an excellent kind of communication.

The metaphor I like to use is that these communication-type things are like the lubrication of a large machine. “Oil” (except it’s not necessarily “oil” in any simple sense – I understand that some clever advanced chemistry can go into this) cannot do anything on it’s own, but without it a machine will work badly, or seize up and not work at all. It is therefore essential.

Which is why I think of bike training, campaigns, the fact that people are actually visibly out there, going into work, the shops, school, the pub, on a bike, or on foot, as “building mental infrastructure”.

Physical infrastructure assists you in going to physical places. Mental infrastructure assists you in thinking particular thoughts. Not using the car is, for many people, literally unthinkable. Anything which makes it thinkable could be described as mental infrastructure.

The solutions

Last week I drew your attention the the causes of Too Many Cars, (and, fortunately, no-one reads this blog, so I’m not wading through a bunch of indignant comments about Freedom and Choice). I showed this diagrammatic summary of the ‘vicious circle’:

.

Unsurprisingly, there is a corresponding diagrammatic summary of the solutions, the ‘Virtuous circle’:

You will notice that it’s a very similar diagram but with the arrows going the other way. Which implies to me that there are many possible Things That Can Be Done – and the trick might be to operate on many fronts at once.

(Source: the Levett-Therivel sustainability consultants. This graphic is quite well-known, I think, and I found this copy here.