I found this to be an interesting article about how science may have found the pathway between exercise (namely Yoga and Pilates) and stress levels. A skeptical scientist who doesn’t do anything unless its proven to him discovered that neural connections exist between muscles, adrenal glands and the cortex of the brain. Just doing exercise you love (or love to hate) demonstrates that how we move has a direct effect on how we feel, but the actual neural process hadn’t been elucidated. Researchers used a monkey model to observe that the movement control areas of the brain (motor cortex) directly connect to the adrenal glands (site of the flight/fight hormonal response). Thus, the motor area of the brain not only influences movement, but also the stress hormones.
This connection offered a scientific basis for how mental states and brain-muscle connections can alter organ function and stress levels. (Scientific abstract here.) Well, duh.