Hey. I just started at an awesome new gym, where the leg machines are numerous, free, and all in the same place.... which got me started thinking about circuit training...

Basically, I'm going from one machine to the next in rounds, being careful to alternate machines working different leg muscles.
This will build muscle as well as the regular old waiting a minute between sets, won't it?
And, if I'm doing, say, 4 machines in a circuit, then going upstairs to do another 3 different machines for a second circuit, how many sets should I be doing? 3? 5?