lightbrite, I think I’ve vaguely heard questions about yoga, but I think most hold it’s OK. Can you point me to information that it’s not?
Also, there’s nothing wrong with long walks on Shabbos as long as you stay in the techum. For the majority of American Jews who live in metropolitan areas, it would be possible to walk many miles without concern.
Although we’re not allowed to fast on Shabbos and Yom Tov, we’re not required to overeat.