Hatha means moving in two directions, not unlike Yin-Yang. Of the many forms of yoga, athletes seem to really like Iyengar yoga. It is rigorous and tremendously challenging. But you start slow. Like running a marathon, you can do it faster overall if you don't go out too fast.
Yoga is like that.
You breathe into the posture and extend the stretch. Each time you stretch you go further than you did the time before. Running tightens, yoga loosens. Yoga Circle teaches Iyengar Yoga. To learn more about Iyengar yoga, go here .