Not merely a race, but a "social fitness experiment," the upcoming SkirtChaser 5K on Nov. 15 is an innovative concept where the women, clad in skirts (included in the entry fee), all take off from the start line at 2pm promptly, and three minutes later, the men follow (get it? "skirt chaser?"). Regardless of gender, the first person to cross the finish line will go home with $500. Awards will also be given to the second and third place finishers, as well as a special "Skivvies Award" recipient.

The race starts and ends at Golden Gate Park at the Music Pavillion (Fulton at 36th Avenue/Lincoln at 41st Avenue), concluding with a block party full of food drinks, live music and a fashion show.

SkirtChaser is giving away two free deluxe registrations to 7x7 readers. To qualify, simply answer the question below in the comments section before noon on Monday, Nov. 9, and we'll contact you if you win.

How do you keep your fitness routine fun and exciting?

Thos who don't win the contest can register online at Active.com through Nov. 11 or in the store at See Jane Run. SkirtChaser is sponsored and organized by SkirtSports, the creator of the original running skirt.