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.

Notebook: why did the cycling demonstration towns fail?

Well “fail” is not the right word; they did achieve some good stuff even though they didn’t live up to the original ambition of the project. I think the CDT project is best viewed as having built some mental infrastructure – and here in Bris some useful physical infrastructure as well.

I’m writing this now because I was looking for something to push the previous post off the top of the stack (so’s I don’t look like a sluggard who leaves old news lying around) and Dave Horton has just listed some possible reasons for the somewhat disappointing results of the project. He’s talking about Lancaster, but I think his comments can be extended further. In addition to the main post he gave a numbered list in reply to one of his commenters, and I think this is worth repeating. His comments are here and here is a filleted version:

“First, the money & status associated with being a Cycling Demonstration Town was seen as more about the money & status than about the cycling (i.e. key people saw things ‘the wrong way round’;

[My comment: yes, for sure – and I bet the same thing applied to Bristol – and all the other places. But what can we do about this? We’re back to this whole nebulous thing of “changing cultures” arn’t we?]

“Second, the project’s goal to enable more short trips to be made by bike very quickly got transformed (because it is easier to do) into a focus on making the district a more attractive cycling destination (i.e. the project became about using cycling to sell the area as a tourist destination, much more than about doing the difficult things required to get local people cycling). That’s a bit unfair (I’m skipping some important detail), but I’m confident of my general point.

[My comment: presumably this only applies to specific towns which have some sort of tourist trade – not all the CDM towns had this – something to be aware of if and when “son-of-CDT” comes to pass]

“Third, people (including key decision-makers, but also ‘ordinary’ local people) were never convinced of the case for re-making the district around bikes. That’s because there were too few people articulating that level of vision and ambition, and they were too peripheral to the process. The main people in the project, in other words, didn’t believe in the product they were selling enough (and related, were not sufficiently charismatic).

[My comment: this seems to me connected with the first point. I don’t know enough to make a detailed comparison between the Bristol and Lancaster experiences, but I recall there was a definite feeling of distrust among Bristol cycling campaigners when Cycling city started – it started with a whimper not a bang. Again, what can be done – what can we do about it?]

“Fourth, that local institutional capital which did get built during the six years of the project was immediately lost when it got cut. Key council officers were made redundant, the dedicated website became neglected etc.

[My comment: in other words, the gains are being rolled back. Bristol had its stint as a “cycling city” later than Lancaster, and we are still able to draw on it. It feels like we haven’t yet slumped back into business as usual and we’ve still got some momentum, but that there are forces in that direction.]

Oh, time for a picture, I think. One of the cycling demonstration towns was Southport. I know the town and had cause to visit it shortly after its CDT term. Was there any difference? It should have been perfect for cycling – flat as a pancake and ridiculously wide roads. No difference visible to my casual eye, apart from these cute cycle stands (unsullied by actual bikes, you will note):

Southport cycle stands

Roads protest

There has been a (fairly) recent announcement of a programme of road-building. Other blogs talk about it here and here.

This is not really a proper post, but I have a choice between the perfection of a lengthy and closely-argued essay (featuring “induced demand” and SACTRA and whatnot) which will get posted, oooh, possibly never, and a quick snippet now. I’ve gone for the snippet, of course, and I’m about to go for a guilty confession.

There’s a protest rally, this Saturday, at Crowhurst in East Sussex (where they’re currently having a spot of by-pass bother). I really ought to go because I do feel just a little bit strongly about this. The trouble is I absolutely hate being in a crowd, especially in hot weather (it provokes migraines and I don’t tan, though sometimes the freckles join up to create a pointillist effect). And it takes four hours to get there by train – if I was still in London, then perhaps… Anyway I’ve gone and donated the cost of a return train fare from Bristol to the Campaign for Better Transport.

As explained previously, I am not an activist I am a sitonmybumandthinkivist.

(There are a number of things I could say about the popularity of roads projects amongst politicians – about the satisfaction of Big Symbolic Gestures perhaps … but if anyone at all is reading this I think you already know the song … )

Not too agressive I hope …

I put this sticker on the bike. Then I tried to take it off because I’m generally rather weedy about making political statements in public. But it won’t remove easily. Anyway, it might make it less nickable maybe?

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And why would people take it as agressive anyway? “Who are all these people?” drivers moan at a spot of unexpected congestion – so surely everyone agrees that the fewer the better?