Yoga and stretching also helped people get off their pain medications. After 12 weeks, twice as many people in the yoga and stretching classes (40%) reported decreasing their medication use, compared with the self-care group (20%). That benefit lasted for another 3½ months after the classes ended.
Neither yoga nor stretching was more effective than the other, however. “We expected back pain to ease more with yoga than with stretching, so our findings surprised us,” said Karen Sherman, lead author of the study and a senior investigator at the Group Health Research Institute in Seattle, in a statement.
The findings may be attributed in part to the fact that the exercise classes ended up being so similar to each other. The stretching classes were more intensive than most such classes, with participants holding each stretch for a relatively long time. “People may have actually begun to relax more in the stretching classes than they would in a typical exercise class,” Sherman said. “In retrospect, we realized that these stretching classes were a bit more like yoga than a more typical exercise program would be.”
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In an accompanying commentary, Dr. Timothy Carey of the University of North Carolina said doctors should feel comfortable prescribing either yoga or stretching for patients with back pain. “Are the results from this trial actionable for practice?” he wrote. “Yes.”
But Sherman cautioned that not any yoga or stretching class will do. The classes in the study were designed specifically for people with back problems and with no previous yoga or stretching experience. “It’s important for the classes to be therapeutically oriented, geared for beginners and taught by instructors who can modify postures for participants’ individual physical limitations,” she said.
Sora Song is the editor of TIME Healthland. Find her on Twitter at @sora_song. You can also continue the discussion on TIME Healthland’s Facebook page and on Twitter at @TIMEHealthland.