The UK is becoming more and more sedentary. Physical inactivity currently costs the NHS around £1bn each year; including costs to wider society, this rises to around £7.4bn each year.

The big four causes of preventable ill-health are smoking, drinking alcohol, poor nutrition, and lack of physical activity. Of these, the importance of regular exercise is the least well-known. However, evidence is growing.

A recent report by the Academy of Medical Royal Colleges, Exercise – the Miracle Cure showed how regular exercise can prevent dementia, type 2 diabetes, some cancers, depression, heart disease and other common serious conditions. Keeping physically active can also reduce the risk of early death by up to 30 per cent. England’s Chief Medical Officer and the UK government recommend adults get 150 minutes of physical activity each week.

In 2015, however, 34 per cent of men and 42 per cent of women reported that they did not meet UK guidelines on physical activity. According to the British Heart Foundation women are 36 per cent more likely to be considered physically inactive than men. While the majority of adults across the UK are aware of the need to exercise and be physically active, we increasingly find adopting these behaviours challenging.

One of the best ways to increase exercise is through changing our everyday travel behaviours – for example, by cycling more. But for too long, cycling has been seen as a fringe activity in UK cities. This is despite the fact that the size and density of most UK cities are perfectly suited for travel by bike. For example, almost three quarters of trips in Greater Manchester between 3km and 5km are driven. These journeys could be ridden by a cycle at a leisurely pace in around 20 minutes.

Despite this, almost all roads in almost every UK city are currently designed to prioritise cars over other forms of transport. This isn’t surprising considering how easy we make it for people to get in a car and hard for people to walk, cycle or use public transport. And this is despite evidence that shows the latter is better for our health, air quality, congestion, climate change and the economy.

So what would the impact be if cities prioritised everyday cycling?

Sustrans’ new report Transforming Cities: The potential of everyday cycling is based on data from Bike Life, the largest assessment of cycling in UK cities, and highlights the impact of doubling cycling trips every eight years between 2017 and 2040. The modelling follows the UK government’s Cycling & Walking Investment Strategy, which seeks to double cycling in England by 2025.

We found an estimated 34,000 incidences of eight life-threatening conditions – including Type 2 diabetes, stroke, breast cancer and depression – would be prevented in seven major cities between 2017 and 2040, if cycling increased at rates like those seen since the millennium in London.

In 2040 and each year thereafter this would equate to over 240 million hours of additional physical activity and the prevention of 628 early deaths. Between 2017 and 2040 cycling could generate £21bnof savings to the economy, including £319m of savings to the NHS.

Cities, including London, Bristol and Cardiff, have shown cycling rates can double over an eight year timeframe. However, we need this to be commonplace in the UK rather than the exception.

The substantial health benefits from increased cycling are only possible if long-term political commitment and investment across government exist at both the city and the national level. Cities will need the courage and conviction to redesign streets and make cycling accessible to everyone. We need to make it easier to cycle than drive in our cities and this means dedicated space for cycling, and making our roads safe enough for a 12-year-old to cycle.

Sustrans, along with other walking and cycling organisations, wants the UK Government to commit 5 per cent of the transport budget on active travel, raising to 10 per cent by 2025 in the next Comprehensive Spending Review. This would amount to £17 per person annually in 2020-21, rising to £34 per person in 2024-25 in England. Similar commitments should then be made in the devolved nations, so as to help cities to invest. As Andy Burnham, mayor of Greater Manchester recently said: “We are made to move and now is the time to act on this”.

Tim Burns is senior policy & partnerships advisor at the sustainable transport charity Sustrans.