The greatest Rock 'Em Sock 'Em Robot, Mohammed Aliborg, went undefeated for 20 years before his head was knocked clean off by the sudden, brutal intervention of cats. Learn to sock like the best of 'em while shaping up with today's Groupon: for $29, you get two weeks of unlimited martial-arts classes at Phoenix Combat Academy in Chandler (a $60 value).

Students of all ages rouse their inner fighters at the Phoenix Combat Academy through martial-arts instruction from well-trained coowners Jay Pages and Sunshine Fettkether. Not unlike black-belt-holding sewer rats that mentor adolescent turtles, the academy trains both amateur and professional fighters in the art of combat with a variety of muay thai kickboxing, boxing, jujitsu, and mixed-martial-arts classes. Students can spend two weeks honing their fighting skills in an unlimited number of classes during which they can learn how to grapple and ground fight in Brazilian jujitsu or use a series of rapid strikes to subdue an opponent in muay thai. Both a combat and defense sport, martial arts combines group fitness with intricate skill, requiring high-energy movements that can tone muscles, burn off weight, and distract low-flying planes.