True HIIT is actually quite unpleasant - but it's over with FAST.

Research it on google. Here's a link: http://www.musclemedia.com/training/hiit.asp

I'm not doing it right now, but when I do, I either RUN (not jog, RUN) a block, walk/jog two blocks, and repeat this 4 times, or I RUN 30 seconds and walk/jog 90 seconds, and repeat 4 times.

Like I said - if you do it properly, you'll feel like your gonna DIE, but it's done with fast.

I'm sure there are others here who know more about it. You can do it cycling, eliptical trainer, stepper, any of these. You can even do it skipping.

But trust me on the lifting. And hit the weights HARD.