I'd love a workout that was metabolic, rotating back and forth between one set of upper body and one set of lower body; such as a set of 15 squats, then a set of 15 one arm rows, then a set of 15 deadlifts, then a set of 15 pushups. Etc. The upper body rests while the lower body works and vice versa. That way you can go really heavy on the weights to get the strength and hypertropy effects, allowing the muscles a good rest period, while still keeping it very cardio and metabolic. Not to mention the non-boredom factor of a constantly changing body part being worked.
Beth
Beth