Training & Nutrition - Circuit Training

I was just wondering if anyone incorporated circuit training into their regular training regime with a focus on core muscles and aerobic fitness? I have done these before and have seen a lot of improvement in a short time and am looking at using this to compliment my on-the-bike training. If at an intense enough level, they can be considered interval training as well with adequate control of heart rate. Any thoughts?

I'll bump this through one more time and then I'll let it go.

I used to do some circuit training a few years ago, probably for a couple of years. It is a great overall conditioning, both for fitness and strength. I stopped doing it because of the high impact of some exercises.

I have taken-up spinning recently and intend to supplement with some exercises for the upper body, not sure yet of the program I will follow. But overall, any impact exercise is what I am trying to avoid.

I do circuit training on a regular basis, 3 times per week, alternating between two different programs. I find it a great compliment to my regular routine as it helps to fill any gaps that may have been left open. I typically, as you noted, focus on core and aerobic fitness in these sessions, and have found this to be an instrumental part of my overall conditioning level.

I do circuits as well alternating between 2 diff programs also. I dont use any weights.. all of my workouts are body weight workouts. It works good for me.. plus i figure if i cant lift my body weight for 3 sets of 12-15 reps then i don't deserve to go to weights... it has helped me out a bit.. i also do intervals on a bike to get the cardio in.