He recently wrote about metabolic conditioning - what it is and how it can benefit you - and, of course, included a workout.While you can find the workout with accompanying videos on his blog, I've also included it here for your convenience and under the WORKOUTS tab for future reference.
If you complete this circuit three times through, your entire workout could be anywhere from 45 to 60 minutes. Depending on how much time you have on any given day, you can alter the number of rounds you do. As for the dumbbells (and kettebell), I recommend using a weight that is challenging. In order to know what is challenging, follow Sisyphus No More's general rule for metabolic conditioning - keeping it tough. As he says, this workout is "supposed to push you way past your comfort zone. If you're not seriously out of breath and tired after one round of this workout, then your weights are too light or you're going too slow - or both."
Perform each complex followed by 45 seconds rest, 1-3 times through
TOTAL: 15-20 minutes once through