Well, I started yoga up again last week, after a two month hiatus (opps!). But you know what? My body remember the postures and I didn't find the class to be too challenging despite my lack of practice. I guess my muscles have remembered! You can read my Yoga, Part Two entry (and be linked to Part One) here.
Part three yoga benefit: stretch!
Work those muscles! During a typical yoga class you will feel deep, long stretches of your use-everyday-but-never-get-stretched muscles, in addition to muscles that you don't even know exist! Seriously, I felt sore in places that never felt sore before in my life; that means I've worked a deep/hidden muscle well.
Yoga really helps athletes (runners, curlers, golfers, dancers, etc) because it too stretches muscles that may be over worked during their respective sports.
Feeling tense due to stress or bad desk posture? Yoga can help there too. Release the tension held in your shoulders with a good, long downward dog pose. Feeling stiff all over? Yoga will certainly loosen you up.
Stretching muscles is also good for detoxification and revving up metabolism. Stretching opens the muscles up, releasing any toxins stored deep within.