Regular exercise is beneficial, but it does not reduce the risk of an otherwise sedentary lifestyle, a new study has revealed.

Sweating at a gym every morning may not prevent you from the risk of diabetes, heart disease, obesity and premature death, if you sit the rest of the day, said researchers.

"We all know someone who gets a good workout in every day, but then spends a large portion of their day sitting in front of a computer with few breaks," the New York Daily News quoted Lynette Craft, lead author of the study and adjunct professor of preventive medicine at Northwestern University`s Feinberg School of Medicine in Chicago, as saying.

"If these people could replace some of the sitting with light activity - just getting up, moving around, maybe standing up when talking on the phone, walking down the hall instead of sending an email - we do think they could gain health benefits," she said.

The study, published in the International Journal of Behavioral Nutrition and Physical Activity, looked at whether women who exceed the federal government`s current Physical Activity Guidelines for Americans - getting at least 150 minutes of moderate physical activity a week - are less sedentary than those who don`t meet the guidelines.

While many of the women in the study met or exceeded 150 minutes of physical activity per week, in reality only a fraction of the women's days were spent being physically active.

The women in the study spent an average of nine hours a day sitting.

"I think some people assume, 'If I'm getting my 30 to 40 minutes of physical activity a day, I'm doing what I need to do for my health," Craft said, noting that people now sit even longer than they sleep.

"Of course, exercise is very important and is associated with many positive health benefits, but negative health consequences are associated with prolonged sitting, and this study shows that just because you`re physically active doesn`t mean you`re sitting less," she stated.