I love yoga. To me, yoga is the best kind of workout, not only because I firmly believe the ancient Greeks did it to prepare for the first Olympics, but also because it's a complete workout that requires very little "stuff". Going to the gym is great but, to me, it seems like such a backwards thing to do. You have all your exercise machines for running, stair climbing, bicep curls, shoulder presses, blah blah blah....yet all those things can be achieved without a machine.
Yoga uses your own body, the law of gravity, and the law of SQUEEZING to work your entire body - with only a yoga mat and towel (which you don't even need). Why jump on a machine and spend hours of wasted energy, when you can do the eagle pose that works your butt, shoulders, arms, legs, and back all while just merely standing in that pose? (Try it, you'll be sweating bullets) Did the ancient greeks have the Bowflex Revolution Home Gym machine? I think not.
Eagle pose for your reference
