Wow heaps of knowledge and expertise here, big thanks for all this! I am doing classes, Zumba gold, very low impact, and Zumba toning, uses interval training, some fast songs some slower, mix of low impact & high impact but not as quick as Zumba fitness, which seems to be high impact and would completely do my knees in. The toning is at a rate that lets me figure out safe alternatives, but I am still getting a good workout. I'm not counting it as ST, back to the drawing board on that. And loving the Zumba, so can't fault it, because I WANT to go to classes, the most important thing for this Sparkie.
all for your thoughts.