Current recommendations prescribe 30 minutes of moderate physical activity most days of the week, for a total of 150 minutes per week.
However a new study suggests a more intensive regime may be necessary. Researchers enrolled 201 overweight and obese women between 1999 and 2003.
All were told to eat between 1,200 and 1,500 calories per day and were then assigned to one of four groups based on physical acticity.
The 24.6% of women who did maintain a loss of 10% or more over the two years reported performing more physical activity, in the range of 1,835 calories per week, or 275 minutes per week over the baseline level of activity.
Archives of Internal Medicine (2008) 168: 1550-1559