More than a billion adults are at risk of serious disease through lack of exercise, according to a new study.

In 2016, just under 20% of the global population - 1.4 billion people - were insufficiently active, the research conducted by the World Health Organisation (WHO) found.

As a result, they faced an increased risk of heart and artery disease, Type 2 diabetes, dementia, and some cancers.

The research shows there was little progress in improving physical activity levels between 2001 and 2016.

High-income Western countries have the greatest increase in the proportion of people not doing enough exercise over the period, with a rise from 31% in 2001 to 37% in 2016.


Image: The recommended healthy level is at least 150 minutes of moderate intensity

In the UK, 40% of women and 32% of men were insufficiently active in 2016.

Countries with the worst physical activity record included Saudi Arabia and Iraq.

In each of these countries, more than half the adult population was insufficiently active.

WHO's Dr Regina Guthold, who led the research, said: "Unlike other major global health risks, levels of insufficient physical activity are not falling worldwide, on average.

"Over a quarter of all adults are not reaching the recommended levels of physical activity for good health."

If current trends continue, the global target of reducing sedentary lifestyle by 10% by 2025 will not be met, the scientists said.

Image: Those who don't exercise face an increased risk of heart and artery disease

Researchers analysed information from 1.9 million men and women who participated in 358 population surveys.

The study was based on self-reported activity levels both at work and at home and during travel and leisure time.

In 2016, around one in three women (32%) and 23% of men worldwide were not attaining recommended healthy levels of physical activity.

This means they were doing less than 150 minutes of moderate intensity, or 75 minutes of vigorous physical activity per week.