The Northern Virginia Senior Olympics is holding a Twilight 5K at 6 p.m., Saturday, Sept. 22 at South Lakes High School in Reston. Registration for this event ends Friday, Aug. 24, at www.nvso.us. Any resident of Northern Virginia who is 50-years-old or better is eligible to sign up. The 5K in Reston is one of more than 60 events in the NVSO this year which include a 10K and 20K cycling race at Vint Hill near Warrenton. The deadline for online registration at www.nvso.us is Aug. 24. Paper registrations must be postmarked no later than Aug. 20.