I've read an article or two that talks about the cardio benefits that can be had by performing weight lifting in a circuit or superset fashion. For those who are'nt familiar with WL circuits, its basically performing a series of weight lifting exercises back to back with little to no rest in between. This type of workout raises the heart rate to what some say is equivalent to performing cardio, of course intensity, weight amount and number of reps will affect the overall heart rate. Anyway I'm just curious if anyone on the board here uses that type of method for their fitness training. What's your thoughts? Is this a good alternative to doing cardio? It seems like a really efficient way to make use of work out time.