Mark your calendars, fans of the latest fashion and fitness! This weekend, Gilt Groupe, the online boutique, is launching a "Get Fit Weekend" with a cool sale stocked with sneakers, fitness gear, and even gym memberships, all selling way below retail value. The site is advertising a range of New Balance and Reebok sneakers for women and men, Crunch classes and personal training sessions (offered at 20-45% off!), plus yoga gear from NaLa Seattle and even jogging strollers and waxing packages. So take your marks, get set, and log on for some good spring bargains. But make sure to warm up first. These items will go fast.