Yoga is unique in that it is the only medieval physical-fitness art that does not involve firing crossbows at a grendel. Bend and stretch sans bloodshed with today's Groupon: for $40, you get a one-day rafting and yoga excursion from Sunshine Rafting Adventures in Knights Ferry (up to an $80 value).

The maritime guides at Sunshine Rafting Adventures captain healthy Saturday adventures down the Stanislaus River with the one-day yoga and rafting excursion, which takes place from 8 a.m. to 4 p.m. The eight-hour trip provides paddlers with all the necessary rafting and yoga gear, including safety equipment, lunches, and detachable joints. Rafters float down watery slopes with ease, requiring no previous experience to enjoyably master their currents. Trips run between 8 and 14 miles, depending on the river's flow level. During resting times, yogis will strive to stretch and strengthen muscles by leading everyone through two outdoor yoga sessions. Drums harmonize with heartbeats amid the bending and twisting, with instructors customizing poses to the group's skill level. A catered lunch breaks up muscle maneuverings, and for an extra fee ($35), paddlers can opt for a lunchtime massage, which limbers up their dorsal muscles and fins before they jump back into the watery saddle.

Though Sunshine Rafting Adventures offers its own kickoff special, this still offers the best deal available. Plan ahead to make sure you're redeeming your Groupon at the most opportune time.