The borough was one of 26 English local authorities where more than 35 per cent of over 16s were found to take part in less than 30 minutes of moderate physical activity each week.
Its ‘physical inactive’ rating of 40.2 per cent was second only to Hartlepool on 41.5 per cent and is the equivalent of 23,000 people.
The findings form part of a new report produced by Spirit of 2012, an independent trust set up to build on the legacy of the London 2012 Games.
On the back of the data, it warns of a public health emergency facing the country amid persistent low levels of physical activity.
The report outlines eight principles it wants central and local government, as well as organisations and employers, to adopt to boost fitness levels. Among this advice is to move away from the body images often depicted in stock photographs of people exercising, which it says can set intimidating targets.
The report also has 10 policy recommendations, including targeted interventions at ‘transition points’ in people’s lives, such as when they leave school or when they face new caring obligations.
Speaking at the launch of the report on Thursday, Ruth Hollis, chief executive of Spirit of 2012, said: “For a quarter of a century in this country, we haven’t even dented levels of inactivity.
“There are a number of reasons for that. However, there are many grassroots programmes that have successfully shown that many of the barriers to becoming, and staying active, can be removed.
“The eight principles we’re launching today in this report are the key ingredients for facing off the looming public health emergency.
“Now is the perfect opportunity: levels of activity, such as walking and cycling surged during lockdown, but this is already on the wane.
“We’re calling on national and local governments, public health organisations, employers, and civil society to adopt these principles, and design sustainable strategies for decreasing levels of inactivity in adults before these habits are lost.”
Find the report at spiritof2012.org.uk