It's mind over matter when it comes to working out, a Canadian study of physical activity suggests.

In Thursday's issue of BioMedCentral’s journal Public Health, researchers said psychological concerns were the important barriers to an active lifestyle, based on a nationwide series of telephone interviews with 5,167 Canadians aged 15 to 79 in 2002.

"Our findings highlight the need for health promotion programs to enhance people's confidence and motivation, as well as providing education on the health benefits of physical activity," said Sai Yi Pan from the Public Health Agency of Canada, who led the team.

The study also looked at respondents' "self-efficacy" — one's self-confidence in the ability to regularly do a total of 30 minutes of moderate level physical activity or PA three or four times a week and a total of 60 minutes of light activity each day, which Health Canada recommends.

Higher self-efficacy scores were consistently related to higher physical activity itself, regardless of gender, age, education level or level of family income, the researchers found.

People who have higher self-efficacy toward exercise perceive fewer barriers to physical activity, or are less likely to be dissuaded by them, and will be more likely to enjoy working out, the researchers said.

Intention to be physically active over the next six months was also another important factor in actually working up a sweat.

Family income, self-rated health and perceived barriers also made a difference, the researchers reported.

"This study suggests that PA promotion strategies should be tailored to enhance people's confidence to engage in PA, motivate people to be more active, educate people on PA's health benefits and reduce barriers, as well as target different factors for men and women and for differing socio-economic and demographic groups," the team concluded.