The Cambridge Sports Union is one of the Boston area's premier running, skiing and orienteering athletic clubs boasting members from all corners of greater Boston, Massachusetts and beyond. CSU's running section hosts training runs throughout the year in Boston area locations including the Commonwealth Avenue stretch of the Boston Marathon course, Boston University's indoor track, Fresh Pond in Cambridge and the trails of Walden Pond and the historic Battle Road. CSU members participate in a variety of races including the New England Grand Prix series championships, Pub Series, Mt. Washington Road Race and the Boston Marathon among many offerings that make Boston a running Mecca(!?).