Yoga emphasizes seamless transition between poses, a skill set adopted by the Navy to teach cursive flag semaphore to its sailors. Spell out serene stances with today's Groupon: for $38, you get 10 yoga classes at Betsy's Hot Yoga Louisville (up to a $145 value).

At Betsy's Hot Yoga, owner Betsy Jones-Cooper and her experienced team ply stiff bodies with tropic-like temperatures to sculpt strong, lean muscle. Dotted with 12 class types ranging from 60 to 90 minutes each, the studio's schedule provides flows to match any fitness level. Beginning benders head to sultry Bikram sessions to flex through 26 poses designed to safely stretch tight tissues and detoxify the body through intense perspiration, precise alignment, and lectures from household sponges. Instructors turn down the thermostat for comfortably warm Vinyasa classes, helping students harmonize breath and movement through an intense, continuous sequence of balances and bends that connect seamlessly through each inhale and exhale. Meditative Yin yoga keeps seats tethered to the floor and minds from wandering with passive backbends and hip-opening postures, and heart-pounding hot-fusion classes pace energetic Bikram and Vinyasa moves to pop tunes and the occasional Benny Hill sketch.

Just as high ceilings and a wall of windows contribute to the studio's airy aesthetic during sweltering classes, on-site showers and changing rooms improve yogis' aesthetic after practice. Rented mats and towels (available for $3 at the front desk) stand in for those left at home, leaving workout bags with plenty of room for water or inspirational coils of copper filament.