There can’t be too many commuters who aren’t now aware that ditching the car and walking to work is much better for them. Considerable evidence has shown that walkers and cyclists are likely to weigh less and be slimmer than their car commuting counterparts. What they may be less aware of is that ditching the car in favour of the bus, train or the tube could have nearly the same benefits. A programme of research by a team at the London School of Hygiene and Tropical Medicine and the ESRC International Centre for Lifecourse Studies, UCL has been taking a closer look at the benefits of being an ‘active commuter’. As researcher Ellen Flint explains, the findings point to some clear ways forward, not just for individuals, but for policy makers too.
Physical inactivity and being sedentary for large parts of the day are a leading cause of obesity and premature death. In England alone something like two thirds of adults do not meet the recommended levels of daily exercise. At the same time there are growing numbers of people commuting to work. In England and Wales that figure is around 24 million people, 67% of whom take the car.
The time of life when most adults become obese is in middle age, with 50-65 year-olds less than half as likely as young adults aged 16-29 to use public transport, nearly half as likely to walk to and from work and two thirds less likely to get on their bikes. So it’s this age group that we have focused on in our programme of research looking at the relationship between active commuting and obesity in mid life.
To help us do this, we have used information from a long term household survey called Understanding Society and a large study called UK Biobank.
Public transport benefits
Our first piece of research used Understanding Society and showed us that not just walking or cycling to work but even catching the bus or the tube are all linked to lower body weight and body fat composition compared with those who get to work by car.
7,534 BMI and 7,424 percentage body fat measurements from men and women who took part in the survey were used in conjunction with information about journeys to work.
Men who commuted via public or active modes had BMI scores around 1 point lower than those who used private transport, equating to a difference in weight of 3kg (almost half a stone) for the average man.
Women who commuted via public or active transport had BMI scores around 0.7 points lower than their private transport using counterparts, equating to a difference in weight of 2.5kg (5.5lb) for the average woman.
When it came to body fat, men who actively travelled to work (walking, cycling or public transport) had body fat that was roughly one per cent point lower than those who commuted by car, confirming the picture seen when looking at BMI.
What’s important to note here is that these differences are larger than those seen in the majority of individually focused diet and physical activity interventions to prevent overweight and obesity.
Second study reinforces
In work just published in The Lancet Diabetes and Endocrinology, we were able to use information from more than 70,000 men and 80,000 women aged 40-69.
More than 60% of these people commuted by car, with only 4 percent and 7 percent respectively reporting walking as their only method of commute and 4 percent and 2 percent cycling. Around one in five was an active commuter some or all of the time.
Except for those who mixed car and public transport, all other groups had significantly lower BMI and percentage body fat than those men and women who ONLY commuted by car.
The biggest differences were for cyclists and the results stayed strong even when we accounted for a wide range of other factors such as social and economic background, their general health and even whether or not they did exercise outside of their daily commute.
The men who cycled were around 5 kg lighter whilst women cyclists were on average nearly 4.5kg lighter than their car commuting counterparts.
Unsurprisingly, walking to work had the next biggest association with reduced obesity. Compared with their car commuting counterparts, men who walked to work were on average 3.0kg lighter; and women typically weighed 2.1kg less.
However, what was perhaps more interesting, and what also reinforced our interesting earlier findings from Understanding Society, was that even those who used a mixture of public transport and active methods of commuting still had significantly lower BMI and body fat percentage than those who commuted exclusively by car.
In fact, it was similar to those who only walked to work. Compared with car commuters, men and women who mixed public transport with some walking or cycling typically weighed 3.1kg and 2.0kg less, respectively.
Active commuting at heart of policy
Separately these two studies make interesting reading, but together they combine to make a powerful and growing body of evidence around the benefits of active commuting and do more than hint at potential interventions for policy makers.
There is now a clear case for the health benefits of active commuting to be taken into consideration by transport planners, town planners and urban designers.
Cities can be active by design and the more evidence that we have to confirm that people who commute actively really are lighter and have a healthier body composition, the more impetus there is for these health related outcomes to be at the heart of policy.
It is time to realise the untapped population health improvements potential of these big shifts we can make in how people travel to and from work.
Photo credit: Chris Rubberdragon