Maybe the real reason Rudolph was banned from all of the reindeer games was that he wasn’t dressed appropriately. A bright red nose might help you get into the Christmas spirit, but only a busy pattern on a chintzy knit will help you go down in history at these holiday fitness happenings.

Shirlington Running Club Meetup and Ugly Sweater Holiday Party
The Bungalow Sports Grill, 2766 S. Arlington Mill Drive, Arlington; today, 6:30 p.m.; free;
Head straight over to the pool tables for check-in, and bond over your fashion choices with runners of all ages and abilities. There will be glow necklaces to help make sure the sweaters are seen even in the dark. And once you make it back to the bar after the 3-mile run, there will be raffle prizes, free food and general merriment.

The Ugly Sweater Run
165 Waterfront St., National Harbor, Md.; Sat., 9 a.m., $44 ($50 day of);
Like Santa Claus, this untimed 5K has been coming to towns all over. But this year marks its Washington-area debut. Participants get a knit hat, a fake mustache and — at the finish line — two Sam Adams beers. Kids 8 and younger are free (or they can snag a hat and ’stache for $10). Run organizers ask everyone to bring a new toy to place under the inflatable Christmas tree to benefit Toys for Tots.

Vida Fitness Ugly Sweater Contest
Through Dec. 24;
Your great-aunt’s horrid taste in Christmas gifts could help you win three months of gym membership. Vida Fitness, which has five locations in D.C., is soliciting ugly sweater photos through Twitter and Instagram. Just add #VIDAfitnessDC or #VIDAugly to enter.