Yoga is a much easier way to exercise both mind and body than testing Einstein's theory of relativity by racing a beam of light. Avoid a science-related sprain with today's Groupon: for $60, you get 10 classes at Sellwood Yoga (up to a $130 value).

Under the guidance of brother and sister duo Bill and Savonn Wyland, instructors lead yoga classes in more than a dozen styles that create a bending buffet catering to casual, first time, and experienced practitioners. Variations of Vinyasa yoga take place every day as part of the weekly schedule, with flow sessions acclimating students to basic pose-work paired with rhythmic breathing, and more advanced classes are designed to build endurance, strengthen cores, or rehabilitate Barbies broken by younger siblings. Candlelight Yin with Restoratives slows down mat-bound relaxation as yogis hold poses for longer periods in order to let go of deep-rooted tensions and target connective tissue around the hips and lower spine. For stretchercisers in search of a fitness-bolstering regimen, Yoga for Athletes shoots to pique muscular strength, flexibility, and lung capacity.

Classes gather in Sellwood Yoga's spacious studio under the high wooden rafters to enjoy a peaceful session bathed in light from a wall of windows facing the practice's garden. Sellwood Yoga supports both the community and environment by displaying rotating exhibits from local artists and sporting a front desk carved from a fallen maple tree toppled after a game of lumberjack dominoes. Although the studio asks that each yoganaut brings his or her own mat, those without one can borrow from the studio's stock.

Though Sellwood Yoga sometimes offered discounted pricing, this Groupon still presents the best deal available.