I've had great results from modest (2-3 hrs/wk) investments in hatha yoga, over and above what I get from standard Greco-Roman "calisthenics."

Besides the flexibility, breathing, and posture benefits, I find that the idea of 'chakras' is vaguely useful for focusing my conscious attention on involuntary muscle systems. I would be extremely surprised if chakras "cleaved reality at the joints" in any straightforward sense, but the idea of chakras helps me pay attention to my digestion, heart rate, bladder, etc. by making mentally uninteresting but nevertheless important bodily functions more interesting.