More than 20 million people in the UK are physically inactive, increasing their risk of heart disease and costing the NHS about £1.2bn a year, health campaigners have warned.
The British Heart Foundation says women are more likely to be physically inactive than men and the North West has the highest proportion of people who do not take enough exercise.
The figures were published in the foundation's Physical Inactivity and Sedentary Behaviour Report as it launched its MyMarathon challenge to boost the nation’s physical activity and improve heart health.
Dr Mike Knapton, associate medical director at the BHF, said: 'Physical inactivity is one of the most significant global health crises of the moment.
'Levels of physical inactivity and sedentary behaviour in the UK remain stubbornly high, and combined these two risk factors present a substantial threat to our cardiovascular health and risk of early death.
'Making physical activity easier and more accessible for all is of paramount importance if we are to reduce the burden of inactivity-related ill health.'