Car ownership has the biggest influence over how much exercise londoners do while traveling

Increasing activity levels is a public health priority because lack of exercise is the fourth biggest killer globally and can lead to conditions like type 2 diabetes, coronary heart disease and breast cancer.

At least 30 minutes of moderately intense exercise five days a week, or 150 minutes per week, is recommended, but 44 percent of UK adults fall short. Promoting exercise through travel is a cost effective way of helping people be more active. London Mayor Sadiq Khan also plans to get more people walking and cycling in order to help reduce air pollution.

The study analyzed data from 40,547 people over 6 years who took part in the London Travel Demand Survey (LTDS). Every year, this survey asks people to record all the trips they make on a particular day and how long they take.. Researchers then looked for links between the amount of exercise done while travelling and factors such as car ownership, bike use, age, income, gender and ethnicity.

This study shows that travelling is a big source of exercise for Londoners. Over half of active travel in London is done by people who mainly travel by walking or cycling. Car ownership generally reduces exercise; bicycle ownership promotes it. Compared to the rest of the UK, Londoners are more likely to use public transport, which often includes walking for part of the journey.

After car and bicycle ownership, age is the next most influential factor with people being less active as they get older. Even though studies often find women exercise less, the researchers found no significant difference between men and women in terms of how likely they are to exercise while travelling.

"Active travel is a universal activity in London undertaken by people of all ethnicities, incomes and physical abilities," said study author David Wilby, statistician at Transport for London. "This research suggests that if we make it easier and more pleasant for people to walk, cycle or use public transport than drive a car, it will in turn help people to get fitter and healthier."

Transport for London is the local government organization responsible for most parts of London's transport system. While this new study is thought to be the most detailed analysis of active travel in the UK so far, it did not collect details on an individual's activity throughout the week. However, unlike national travel studies, it does provide information on shorter bursts of exercise. The authors suggest future studies examine the data based on active periods of 10 minutes. This would reflect the Chief Medical Officers' recommendation to increase exercise levels by being active for bursts of 10 minutes or more.

The authors also suggest exploring the impact of other factors like geography, because of the differences the study found between people in Outer and Inner London. For example, people in Outer London are more likely to travel by car, perhaps because they have fewer public transport options. These differences suggest that land use density and access to public transport may be more influential than personal factors. Examining the influence of factors such as social norms may also be useful.