Cycling to work really does make you thinner study confirms

Interestingly, according to the study in the BMJ, using public transport is as effective

by Elliot Johnston   August 20, 2014  

Commuters (CC licensed image by kube414:Flickr)

Cycling to work really does make you thinner, according to findings of a new scientific study published in the British Medical Journal.

Most people who ride to work will have known this already but it's always good to have science on your side too. Armed with this proof, experts will now be louder in their calls for people to leave their cars at home and find more active forms of travel - such as cycling.

The investigation, performed by researchers from the London School of Hygiene & Tropical Medicine (LSHTM) and University College London, took a sample of around 7500 individuals and analysed the relationship between their body fat percentage or Body Mass Index score and their chosen method of transport to work.

The results showed that men who traveled by public transport or were active for part of their commute had respective BMI scores (weight ÷ height) of 1.10 and 0.97 points lower than those who drove.

Meanwhile, women who commuted via public modes of transport had BMI scores 0.72 lower, and those who commuted actively were 0.87 points lower than those who made their way to work through private means of transport.

In terms of the impact active transport had on body fat percentage, the report said that the results were “similar in terms of magnitude, significance, and direction of effects" to those seen in BMI change.

One of the researchers, Ellen Flint, PhD of LSHTM, pointed out that active commuting proved to be more effective in the fight against obesity than dieting and targeted exercise.

Alongside Dr Flint, the study was undertaken by the professor of population health, Steve Cummins, also of LSHTM, and professor of lifecourse studies at UCL, Amanda Sacker.

Dr Flint spoke to Medscape Medical News following the publication of the results on August 19, about the potential benefits of the UK population ditching the car.

She said: "Because the predominant mode of transportation in Britain is the car, if we can affect a large modal shift away from private transport toward public or active modes of transport, there really is great potential to reap large population health benefits on overweight and obesity."

There are all sorts of theories which experts put forward that would encourage cycling among commuters, thus reaping these health benefits. One of the most widely suggested is the improvement of road infrastructure to support safer cycling.

Last month we reported a study which showed that people who lived near cycle paths get 45 minutes' more exercise overall every week.

Research associate at Imperial College London, Anthony Laverty, and reader in public health, Christopher Millett, PhD wrote an accompanying piece to Dr Flint's study which explained that the reduction in body fat observed in association with the use of public transport was the most interesting and important finding.

"This benefit is likely to accrue because the use of public transport generally involves walking and occasionally cycling to transport access points or interchanges, thus increasing incidental physical activity," the pairs’ editorial read.

They went on to highlight that healthcare professionals are additionally well placed to advise patients to 'leave your car at home,'" the authors note. "This will not only improve their patients' health in the short term but also help reduce the likelihood of hazardous climate change further in the future."

The full results of the study can be found on the British Medical Journal website, here.

35 user comments

Latest 30 commentsNewest firstBest ratedAll

Oh, BMI was the measure. Where muscular lean people are considered obese...

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posted by aslongasicycle [330 posts]
20th August 2014 - 21:07

72 Likes

How much grant money were these people paid? At Wits End

posted by Binky [115 posts]
20th August 2014 - 21:57

50 Likes

No shit Sherlock ……….

It took eminent scientists to work this out?! Applause F*** me Rolling On The Floor

Airzound

posted by Airzound [489 posts]
20th August 2014 - 22:25

61 Likes

Of course this is common sense stuff: Exercise (being active) makes you healthier.

However, as Arfa said, this peer-reviewed study is the sort of thing that is great to use in public policy debates and has a chance to influence serious, wide-ranging decisions regarding transport policy.

So, the headline outcome is laughable, but the study is very serious and affects us all.

Ah, f*ck: Do bears execrate among trees?

posted by jacknorell [571 posts]
20th August 2014 - 23:00

57 Likes

aslongasicycle wrote:
Oh, BMI was the measure. Where muscular lean people are considered obese...

BMI was never intended as a measure for athletic people... for the average person it does however work well.

posted by jacknorell [571 posts]
20th August 2014 - 23:01

55 Likes

jacknorell wrote:
aslongasicycle wrote:
Oh, BMI was the measure. Where muscular lean people are considered obese...

BMI was never intended as a measure for athletic people... for the average person it does however work well.

BMI was never intended for individuals, period, since muscle and bone masses varies significantly. But for populations, it is perfectly valid, since variations in muscle and bone masses average out over large sample sizes - for ever person that is actually "big-boned" there is one who is small-boned, for every athlete there is a couch potato.

And to the "bears-shit-in-woods" brigade, the point of a study like this is to eliminate anecdotalism - when someone claims he drove all his life, never exercised once and is still fit as an Olympic athlete, we point to studies like this and say, yes, you appear to be an exception, but on average, for the average person, exercise is beneficial. Otherwise it's really just your words against his, isn't it?

"Common sense" and "hunches" have their place, but if we dismiss serious, rigorous studies solely on the grounds of "common sense", we'd still be thinking the world is flat: "duh, why bother checking, the world is obviously flat!"

posted by Shanghaied [41 posts]
21st August 2014 - 7:53

19 Likes

BMI isn't the best measure, but it is easy to do, unlike measuring skinfolds etc. And there are quite a few people classified as overweight who think they are athletic and muscular, whereas they are a little podgy too!

I started cycling in to work around Christmas. I was a regular cyclist anyway, and already in the healthy BMI range (so fairly skinny according to some). I've lost half a stone despite making no other changes to my diet and lifestyle at all. I must admit I am quite surprised as I had plateaued at my previous weight for about 10 years.

My commute is quite hilly though!

posted by Chris James [214 posts]
21st August 2014 - 8:16

43 Likes

drfabulous0 wrote:
So, men in white coats, having completed this study are you going to ride to work now.

It would mean a lot more if it was women in normal clothes who figured this out.

Two of the three authors, including the lead author, are women. Not all scientists are men you know. No notes on the report as to what clothing the authors wear.

I'd love to know what was behind the drop in BMI for users of public transport. Age, income, social class, disability, diet, activity levels at work and sporting participation were all identified as compounding variables and were all included in the analysis.

posted by pikeamus [46 posts]
21st August 2014 - 8:30

42 Likes

pikeamus wrote:

I'd love to know what was behind the drop in BMI for users of public transport.

This spring I commuted by train (150km a day, so a little to hard to cycle), but that still involved just over an hour of walking, to and from the stations, morning and evening. I would not get that if I was driving, since I'd be driving almost door to door. So I'd guess it's because public transport rarely takes you exactly where you want to be, and most people have to walk a fair bit anyway. Not that that's bad thing, clearly.

posted by Shanghaied [41 posts]
21st August 2014 - 9:21

51 Likes

Unfortunately, as we already know, it doesn't matter what proof there is it only matters who has the loudest voice.

The lead on this is quite simple excercise makes people healthier which is great and obviously that is the angle the cycling community will see and all congratulate ourselves for being provable awesome.

However, mainstream media will go "shock!" and only look at the postive message and not the flip side, that is the cost of those inactive commuters and how they are costing the NHS stupid money and all the rest of it. Afterall, calling vast swathes of people fat, lazy and a drain on the economy isn't always a great selling point (well unless you are one particular newspaper), which unforutnatley the news business is. It isn't "all the news that fits" it is "all the news that sells".

posted by Wolfshade [112 posts]
21st August 2014 - 9:32

40 Likes

I wonder if willingness to cycle and use public transport is indicative of a wider attitude that means you're likely to be thinner?

To the "No $hit Sherlock" brigade- if the study was about whether doing exercise can make you thinner you might have a point, but it's not is it? It's an interesting result that people who take public transport also tend to be slimmer.
Also, as others above have said, sometimes "it's just common sense, innit?" isn't enough to get at underlying causes or relationships, hence studies like this.

posted by Chuck [435 posts]
21st August 2014 - 9:42

52 Likes

pikeamus wrote:
I'd love to know what was behind the drop in BMI for users of public transport.

When I take the bus I walk to and from the bus stop.

When I take the tube I walk even further to and from the tube station.

When I take the train, I drive to the train station, but I also take my Brompton and ride it between my destination station and office, and back again.

posted by congokid [161 posts]
21st August 2014 - 9:45

51 Likes

Public transport does not pick me up from my front door and take me direct to the place i have to go to, unlike a car.

Public transport involves walking to a heck of a lot of bus stops or stations and dealing with a heck of a lot passengers (they give me chest pains)

This research is lame

posted by Binky [115 posts]
21st August 2014 - 10:02

59 Likes

BREAKING NEWS...

Detailed, scientific and peer reviewed study does indeed show that bears shit in the woods.

An insider states "yes, this study is unprecedented, incredible as it may seem but it's taken to 2014 before anyone actually got round to proving it".

posted by HalfWheeler [126 posts]
21st August 2014 - 10:06

41 Likes

Whilst I get the 'do bears shit in the woods' response, with the majority of people in the UK (c 60+%) now overweight and obese, despite huge amounts of noise by government, media, NHS, etc etc, clearly most people do NOT understand what would seem utterly bleeding obvious to us...

The UK is in serious trouble economically already, and the impact on productivity and costs to the taxpayer of the additional load on the NHS could well see us getting poorer and poorer over the next generation, until we can get on top of this.

You kind of need studies like this as common sense appears to not exist when it comes to looking after ourselves

If it was my job to try and get the UK public to understand what we're doing to ourselves and our future wealth and health I think I'd be in despair at the moment.

posted by Brooess [46 posts]
21st August 2014 - 10:13

8 Likes

Slightly puzzled by the reported findings. "Travelled by public transport or were active for part of their commute" were "respectively" 1.1 or 0.97 BMI points thinner.

Odd that "active for part" achieved less reduction than public transport users. What do they mean by active? Perhaps running to catch that bus is more active than the "active" travel adopted by the second mentioned group? Surely public transport users are by definition part-active if we assume they don't drive to the bus stop or station and park right next to where they board their bus/train.

posted by Paul M [325 posts]
21st August 2014 - 10:33

34 Likes

classic schoolboy error of confusing correlation with causation. people who cycle to work have a lower average BMI than those who don't because ... chubba's chafe. cycling doesn't make you slimmer. you have to be slimmer to cycle. well ... apart from the occasional black swan, ahem.

posted by Foxy [1 posts]
21st August 2014 - 14:30

32 Likes

Shanghaied wrote:
"Common sense" and "hunches" have their place, but if we dismiss serious, rigorous studies solely on the grounds of "common sense", we'd still be thinking the world is flat: "duh, why bother checking, the world is obviously flat!"

Good point, well made.

posted by Duncann [90 posts]
21st August 2014 - 17:09

44 Likes

This is great news.

Now we've established cycling makes you thinner (I suspected this for some time), we just have to await confirmation that eating too much food makes you fat.
Once that happens, if we can get some government commission to join the dots, perhaps cycling infrastructure will be upgraded....maybe.

posted by ronin [162 posts]
21st August 2014 - 20:19

31 Likes

congokid wrote:
pikeamus wrote:
I'd love to know what was behind the drop in BMI for users of public transport.

When I take the bus I walk to and from the bus stop.

When I take the tube I walk even further to and from the tube station.

When I take the train, I drive to the train station, but I also take my Brompton and ride it between my destination station and office, and back again.

You wouldn't expect it to be of the same order of magnitude as cycle commuting though, would you?

posted by pikeamus [46 posts]
22nd August 2014 - 8:01

24 Likes

Foxy wrote:
classic schoolboy error of confusing correlation with causation. people who cycle to work have a lower average BMI than those who don't because ... chubba's chafe. cycling doesn't make you slimmer. you have to be slimmer to cycle. well ... apart from the occasional black swan, ahem.

Although I do think this comment misses the point a little, it does raise the valid point that, irrespective of the quite obvious benefits of cycling or walking to work/college/whatever, many people are just too (overweight and) lazy to actually do it.

I think many just bury their heads in the sand when it comes to the consequences of physical inactivity, an "I'm alright Jack" belief that nothing will happen to them, so they can carry on eating, drinking and smoking as much as they like regardless.

posted by parksey [295 posts]
22nd August 2014 - 8:03

14 Likes

Foxy wrote:
classic schoolboy error of confusing correlation with causation. people who cycle to work have a lower average BMI than those who don't because ... chubba's chafe. cycling doesn't make you slimmer. you have to be slimmer to cycle. well ... apart from the occasional black swan, ahem.

You don't have to be slim to cycle, see Ernest Gagnon, but you can't be lazy!

The stronger correlation, I believe, is between fat & lazy; not slim and cycling or active transport.

Cycling has made me drop a 7kg in the last 4 months without trying, btw Smile

posted by jacknorell [571 posts]
22nd August 2014 - 8:41

16 Likes

Despite burning 3000kcal a day, my weight just won't change. I do get ravenously hungry, and you should always listen to your body right?

posted by CharlesMagne [29 posts]
22nd August 2014 - 17:56

16 Likes

Is it possible that for the majority of cycling commuters , being naturally thin is what pre disposes them to cycle to work rather than the other way around? Or is that just too laughable to be true?

posted by wyadvd [123 posts]
23rd August 2014 - 10:34

6 Likes

For all those smartarses above, the BMJ article doesn't say active travel 'makes you slimmer', it just says that:

"- For both men and women, commuting by public or active transport modes was independently associated with significantly lower objective measures of overweight (body mass index and percentage body fat) compared with commuting by private motorised transport

- Further research using longitudinal data is required to confirm the direction of causality".

The cause might well be because, as has been noted above, fat people don't use active travel/public transport. But the paper doesn't make conclusions about causality. So please read the linked article before you comment about how smart you are---or how stupid scientists are.

drmatthewhardy's picture

posted by drmatthewhardy [414 posts]
24th August 2014 - 0:11

5 Likes

Yes it establishes correlation, upon which we rely when drawing any conclusion based upon statistical analysis, including for example, which pharmaceutical drugs make it to market or not. So if this type of analysis is good enough to draw binary yes or no conclusions like that, then it should be good enough to draw binary conclusions like allocating more of the transport budget to active travel away from the car will produce beneficial public health outcomes. This has to be a good thing with the NHS creaking with record amounts of money (we don't have) being spent at the moment - an ounce of prevention being better than a pound of cure and all that.
Of course we could go into factors like "r squared" but that would be getting a little dull really. Far better to email the link to your MP/prospective candidates and say here's some respected research, where do you stand on it as it will influence how I vote.

posted by arfa [542 posts]
24th August 2014 - 6:50

2 Likes

This is exactly what I was about to say.

It's more of a study in the habits of obese people vs the habits of active people.

When I'm heavier and my testosterone is low and seasonal depression is kicking in, I'm not likely to go to the gym or ride to work. I'm far more likely to want to sit in my nice warm car and activate the foot pedals...

When I'm in good spirits and I'm at the gym regularly with a feeling of progress and improvement, I don't hesitate to jump on the bike for a 5k burn.

Another factor here is speed and convenience. I commuted by bike exclusively for around 5 years of my adult life. Two of those years, I also had gas-powered transportation as an option. When I had both options, my commuting to work was generally an issue of convenience. If the route consisted of primarily clear routes where I could make good time, I'd do it (even if the distance was significantly higher). If the route was full of start-stop, choking on fumes, chances are I'd jump on the motorcycle and keep clear of that.

Convenience, pre-existing habits and conditions are causal.

I am an endomorph, so I haven't been considered "skinny" at any point in my life. Not even when I was spending 7+ hrs a day commuting by bike for 3 years... Of course I can lift the average road cyclist + bike over my head without much trouble for 10-12 reps... Wink

posted by eschelar [41 posts]
26th August 2014 - 1:22

0 Likes

"cycling to work makes you thinner" . It does if you get squashed between 2 buses Big Grin

posted by craigx1 [6 posts]
13th September 2014 - 16:33

0 Likes

Should be 'if we can EFFECT a large modal shift'. Plain Face

posted by purplemadwoman [20 posts]
2nd October 2014 - 12:14

0 Likes

It certainly does, but it doesn't make your hair grow back...I can confirm this Confused

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posted by southseabythesea [83 posts]
2nd October 2014 - 12:26

0 Likes