Grab your sneakers and take off for a great cause.The Myrtle Beach Marathon supports the Horry County Chapter of the American Red Cross and the Leukemia and Lymphoma Society of South Carolina. The race includes not only a marathon, but a 5K, half marathon and a Family Fun Run. BB&T Coastal Field, 1251 21st Ave. N. Dates and times vary. $15–$120. (843) 293-7223, www.mbmarathon.com