Ready to get in shape for spring? Or maybe watching 15,000 others do so is more your speed. If you haven't already signed up to participate, join the enthusiastic droves who shout support along the way for the second annual ING MARATHON AND HALF MARATHON Sun., MARCH 30. The course begins downtown and continues through a range of neighborhoods that include Decatur and Virginia-Highland before finally winding down to a finish right back where it started in Centennial Olympic Park. Free. 6:55 a.m.-2 p.m. Various sites. 678-620-3317. www.inggeorgiamarathon.com/site3.aspx.