The research: A study team from Ohio State University measured markers of inflammation among 200 breast cancer survivors—half of whom practiced hatha yoga on a twice-weekly basis. The researchers also collected psychological surveys designed to gauge the participants’ energy and depression levels. Compared to the no-yoga group, the downward doggers enjoyed the lasting inflammation- and fatigue-lowering benefits detailed above.  What it means: The meditative component of yoga is a proven stress fighter, says lead study author Janice Kiecolt-Glaser, PhD. And thanks to the uptick in physical activity, the yoga practicers also slept better at night. Both of those factors could explain the improved inflammation and energy levels, Dr. Kiecolt-Glaser explains. Also, because yoga helps you learn to manage stress through concentration and breathing, its positive effects last even if you stop practicing, she adds.   The bottom line: Anyone who takes up yoga should experience lower inflammation and fatigue levels, as well as better sleep, Dr. Kiecolt-Glaser says. And her study showed the more often you practice yoga, the better the results.  More from Prevention: How Yoga Combats Menstrual Problems