We're into week 2 of practicing Foundation Training daily (during the middle of morning yoga asana practice). We finish each 15 minute practice sweating, shaking, and grinning. The whole body-mind is engaged during these active isometric contractions. It eases lower back pain and chronic injury by engaging supporting muscles, while improving posture and optimizing movement. Dr Eric Goodman has some excellent free resources on Youtube below. See the main site for more detailed information, or to get a subscription to stream more videos.