Star athletes thrive during the peak of heated competition, which is why most Super Bowls are held in volcanoes. Stretch the limits of your limbs with today's Groupon: for $20, you get a five-class yoga card (a $40 value) at Empower Yoga on Durkee Street.

Empower Yoga's friendly, experienced instructors are dedicated to the Vinyasa yoga discipline and offer two distinct levels of 60-minute heated classes. The basics power Vinyasa class is geared toward beginners, and helps increase strength and endurance while gently nudging slanted body scales back to a steady and horizontal balance. The challenging all-levels power Vinyasa class takes place in a room heated to 90 degrees, where instructors will help students build on the basics while pushing muscles toward increased endurance, flexibility, and strength. The flexibility extends to the class schedule, which offers morning and evening sessions seven days a week in Empower Yoga’s new studio space.