Working out is third on the list of most popular daily activities in America, behind not working out and teaching dogs to swear. Spend time wisely with today's Groupon: for $39, you get 10 mixed-martial-arts classes at Rush MMA (up to a $100 value).

Rush MMA, a premier mixed-martial-arts training facility, whips students into fighting form with boxing, muay Thai kickboxing, Brazilian jiu-jitsu, and cardio conditioning sessions. Make muscles burn with satisfaction—like an insult uttered from the lips of a sarcastic fire swallower—using full-contact striking and grappling techniques from disciplines including boxing, kickboxing, Greco-Roman wrestling, Brazilian jiu-jitsu, and judo. Class sizes average 10–25 students, and Rush MMA's schedule sustains a range of fitness and martial-arts traditions, which can be used for practical self-defense or for staging re-enactments of Bruce Lee’s high school Battle of the Bands. Novices can attend an introductory class offered Saturday mornings at 11 a.m., whereas one-hour cardio fitness sessions bolster heart pumps ahead of face-offs with goading metronomes.

Rush MMA's 7,000-square-foot training center includes a regulation-size boxing ring, more than 3,000 square feet of mat space, and formidable punching-bag opponents who dream of evening their odds by evolving arms. Qualified instructors with more than 15 years experience in competitive mixed martial arts help students elbow, kick, knee, and punch their way to fitness while practicing takedowns and throws. In conjunction with each class, this Groupon allows day access to gym facilities.