Here are my super-unscientific results: My yoga poses kept improving over the years (as externally measured) because I unconsciously learned how to avoid tightnesses and weaknesses. I could get away with it by using certain muscles and avoiding others. I think the same could be said for any sport/activity with a measurement goal - the brain is going to quietly figure out how to achieve the goal in the most comfortable way possible. In my case that resulted in atrophy and tightnesses - and the joint problems those bring. So the answer for me has been rooting out the muscles I haven't been using - finding what hasn't been firing lately. The process is looking for where the tightnesses are (stretching). The moment I find that tightness, I know I have 1)fired a muscle differently than normal, 2)found a possible range of motion I haven't been realizing, and 3)kept my brain paying attention to that area in a positive way. The efficiency is huge: the feedback is immediate, so there's no getting mentally lazy and mailing it in as long as the external measurements keep improving...that feeling is either there or it is not. No gray area or external judgment to distract me from actually paying attention...My measurable results: strong abs and other muscle response, open hips, aches/pains free. Most importantly, optimistic outlook for an aging body. A big challenge, though, is the not mailing it in part. I can't just shut off the brain and power through in pursuit of whatever number. I'm not going to end up fatigued, panting, sweating (when that's what I need, I'll do something else). The counterintuition is that I strengthen more by striving less. That's a big obstacle to get over for those of us conditioned by Just Do It fitness marketing. In business terms, it's like finding much more satisfaction and results in an internal audit rather than in hitting revenue targets. It's not at all what we're trained for, but it's where my meaningful improvement was hiding.