The country is building huge future health problems amongst the less affluent, as the extent of UK inactivity becomes clear, the University of Bristol has said.
Data on a million adults in England shows 80% do not hit national physical activity government targets and finds large disparities between inactivity and socioeconomic status.
Overall, 8% of the adult population in England who can walk do not even walk for five minutes continuously in a four-week period and 46% of adults had not walked for leisure for 30 minutes continuously.
The findings provided evidence of a direct correlation between an individual's education, household income and local area deprivation and level of physical activity.
Adults who are degree-educated were shown only to have a 12% chance of being physically inactive, while those with no qualifications are three times as likely to be physically inactive.
Carol Propper, professor of economics at Bristol's Centre for Market and Public Organisation, said: "Physical inactivity is the most important modifiable health behaviour for chronic disease so knowing who is physically inactive is important for designing cost-effective policy interventions.
"These findings show physical inactivity in England has a large socioeconomic gradient with clear evidence of independent disparities by gender, ethnic group, age, geographic area and socioeconomic position.
"They suggest that financial as well as cultural barriers need to be overcome to reduce the prevalence of physical inactivity."
