Other than cross fit, which is being discussed in another thread, what resources do you all have for good stretches and core/back strengthening, and flexibility? I want to further protect and strengthen my lower back etc. Right now, I do basic core, and some basic stretching, but feel like there could be more. I also mountain bike a lot, and go hiking. Used to run, but quit that due to injury, and my IT band getting too tight. During winter, I alpine ski, nordic ski both skate and classic, and attempt to continue core. I do not stretch near enough.