A popular question is the difference between full body circuits vs. body part splits, and how much cardio should be thrown in the mix.
How many times have you heard the answer "it depends." If your goal is to spend less time in the gym, and accomplish the tight toned look quicker; full body circuits and Interval training may be the quickest way to get the best results. (with diet being in check of course.)
Hitting your full body 3 times a week would keep your body in a state of burning more than splitting your body into smaller parts. When you do a full body, you're raising the metabolic burn throughout the whole of your body. This, in most cases, will keep your metabolism higher than if your body is only trying to recover from hitting 1 or 2 body parts. The benefit of body part splits is that you can hit an individual muscle harder.
As for "cardio vs. Interval training." For most cardio is nothing more than a means to burning more calories(energy). No one "NEEDS" Cardio for fat loss. It's just something people do because they want to burn calories. Here's the thing. If you go run at a steady state for 45 min and, as an example let's say you burned 400 calories. After the first couple of sessions your body has adapted. Once you stop, That's it, "calorie burn" stops. Now if we do, let's say a 20 min interval session of, lets say 30 seconds of intense burst and then 2 minutes off, and we repeat that for the 20 minutes. You may burn 250 calories, but because you worked the muscle more intensely, you now have created more of a metabolic burn.
As an example you may burn an extra 200 calories throughout the day. For your 20 minutes of intense work you've burned a total of 450 calories. as opposed to 45 minutes of steady state that burned only 400. I'm not saying there isn't a place for steady state. If you want to get better at running than you will need to run more. Using cardio as a fat loss tool may not be the most efficient way to burn excess fat.
Keep the dream alive. Make the dream a reality, LIVE THE DREAM!!!!