Welsh health survey: One in three take no exercise
Ministers have been urged to do more to encourage people "off the sofa" as it emerges the amount of exercise Wales takes has not changed in 10 years.
Conservatives say the Welsh government's public health strategy must change if it is having no impact.
The latest Welsh health survey shows one in three take no exercise - 36-38% of women and 30-32% of men.
The government said the figures were not unique to Wales, but showed "the scale of the challenge".
However, it said it was targeting teenage girls to try to reduce the gap between the number of women and men who go on to exercise regularly as adults.
The Welsh Health Survey: Physical Activity in Wales 2010 collects information from about 15,000 adults and 3,000 children and started in 2003/4.
The survey questioned people on the number of times they completed at least 30 minutes of moderate to vigorous activity or 60 minutes for children.
It found 57% of boys and 47% of girls reported five or more active days a week.
A report entitled Creating an Active Wales - the government's action plan for physical activity - suggests everyone should do "one day more" activity each week.
This would shift the average point of activity for adults from 2.4 days to 3.4 days.
The survey also showed 52% of children aged four to 15 reported five or more active days in a given week, with 12% saying they completed no activity.
It also found people in socially deprived areas exercised less. The report said the figures were largely unchanged from earlier surveys.
Conservatives' health spokesman Darren Millar said more must be done to "coax people to do more and get off their sofa".
"If they [the Welsh government] are flogging a dead horse it has to change," he said.
He suggested using Team GB's success in the Olympics to serve as a catalyst to encourage more exercise.
A Welsh government spokesperson said while the survey's findings are not unique to Wales they do "demonstrate the scale of the challenge we face and the need for a comprehensive approach including encouraging physical activity from a young age".
The spokesperson said the research suggests the gender disparity develops particularly in adolescence, which could be attributed to a host of reasons, and continues into adulthood.
She said the government's action, Creating an Active Wales, includes a plan to increase participation in physical activity among teenage girls.
"The Welsh government wants more children taking part in regular and frequent activity," she said.
"Programmes such as 5x60 in secondary schools and Dragon Sport in primary schools are helping to create the environment necessary for children to enjoy extra curricular sport and physical activity on a regular basis."
The spokesperson also highlighted its Change4Life campaign, alongside its summer programme Games4Life which encourages families to increase their physical activity.
"While we recognise our role in this important issue, we also recognise people have to take responsibility for their own health," she said.