Tai chi this evening. It's always amazing to me how much work it can be, even though we're not moving quickly and we don't have any equipment or anything. But my heartrate was up and I was breathing heavily and I broke a sweat.
It can also be murder on the thighs. My quadriceps were starting to vibrate pretty badly near the end of the hour, and I had to stand up and rest from the postures several times.
I experimented with trying to bend my legs more this time, droping down further and settling deeper into the stances. It was interesting. There seemed to be some spots where the support comes more from tension in the tendons than it does from force in the muscles, though I think that's probably illusory. I do wonder if I have enough stretch (length?) in my achilles tendons to bend as much as everyone else does.
Stupid defective legs. *harrumpf*