Cambridge Half Marathon + 5K 2026

The Cambridge Half Marathon + 5K Challenge requires runners to complete both races during the CambridgeSide race weekend in Cambridge, Massachusetts. The 5K begins the weekend at 10am, and the half marathon starts at 7am on the next day. Together, they form a two-race running challenge utilizing a 3.1-mile river route and a 13.1-mile USATF certified half marathon course. Both races commence and conclude at CambridgeSide. The 5K follows a swift out-and-back path along the Charles River, offering views toward the Boston skyline. The half marathon is a fast, flat course along Memorial Drive, passing riverfront landmarks and campus scenery that includes MIT, the John W. Weeks Footbridge, and Harvard University Stadium. Challenge participants receive the half marathon quarter zip and the 5K long-sleeved technical shirt. The event benefits local organizations such as Cambridge Camping and the City of Cambridge Scholarship Fund.