On a sunny Saturday last month, thousands of women in colorful gear descended on the Marshfield Fairgrounds for the Shape Diva Dash over an obstacle course. The Dash is among the rapidly growing number of 5K fun runs, obstacle races, mud runs, and endurance activities mostly put on by for-profit, out-of-state companies that bill them more like social events.
For the most part, the companies align themselves with national or local charities. But critics argue that because the companies are private, they are not required to divulge how much goes to charity. Nonprofit road race organizers argue that the rapid growth of fun runs hurts their own fund-raising efforts. Full story for BostonGlobe.com subscribers.
Visit www.boston.com/marshfield to see a gallery of photos from the Shape Diva Dash and the Electric Run.