New research has found that even girls who do engage in sports and other forms of regular physical activity tend to abandon it in their teen years. The study followed girls for 10 years and found that, over time, their physical activity declined dramatically. Temple obesity researcher Clare Lenhart said there could be several reasons why: "They have found changes in enjoyment of activities, in peer support or social support for physical activity. They found a lot of competing interests — be it part-time jobs or caring for younger siblings or other family members."