I know there's very few of us in Alexandria/Southern Fairfax county but thought I'd suggest my group the Kingstowne Striders which just started our track workouts last night. They hold group runs anywhere from Eisenhower Ave to Belle Haven but usually we leave from the Panera/Cinema in Kingstowne (changes each time to switch up the routes) Tuesday/Thursday 6:30pm Saturday/Sunday 8am and track workouts on Wednesdays at Edison High School on Franconia Road just started last night (6:30pm) through late August. Great group, $20 membership for year to cover insurance, etc. Casual runners to serious marathons though I think I'm there only triathlete after our one Ironman just moved to Colorado last month. They host a couple fundraising 5k's through the year too. A couple of us bike to the runs (I live off Van Dorn myself and tackle that hill on Oakwood to get to the runs).