New York

YOGA enthusiasts link the practice to a long list of health benefits, including greater flexibility and range of motion, stronger muscles, better posture and balance, reduced emotional and physical stress, and increased self-awareness and self-esteem.

But definitively proving these benefits is challenging, requiring years of costly research. A pharmaceutical company is unlikely to fund a study that doesn't involve a drug, and in any event, the research requires a large group of volunteers tracked over a very long time.