Best Trendy Fitness Event: MuckFest MS

Have a grubby old pair of running shoes taking up space in your closet? We suggest you break ’em out for this wildly popular, mud-splattered 5K, peppered with nearly 20 daunting obstacles that “spin, swing and fling.”  There are currently MuckFests in 11 cities; our version happens in late May on the SAP campus inNewtown Square—and it sells out fast. Run on your own or, better yet, form a team. Proceeds benefit the National Multiple Sclerosis Society. 

www.muckfestms.com.