High Intensity Interval Training

New gym has some really cool aerobic trainers. a scifit upper body bike that has the ability to provide constant RPM work and constant workload, a cybex recumbant bike for lower. I am trying to put together a training schedule and I am torn between using dedicated blocks of isokinetic work, then going to block of maximum effort with increasing wattage.

In my isokinetic work, I have varied the rpms from 50 to 80, changing every workout, using 20 second bursts of maximal effort and 40 second recovery. I tried the tabata approach of 20 on and 10 recovery, too much. I am leaning on alternating sessions to rpm work one day, same 20/10 split, and on the constant work day, doing 30 second bursts up to 60 and using heart rate to determine when to start next burst. any thoughts?

goal is fat loss. maintain strength. I have actually gotten stronger because with isokinetic work, the all out effort is really demanding.

Actually i would say that low intensity long term cardio would be best. Doing so works the slow twitch muscle fibres which respire aerobically for long periods of time (fast twitch respire aerobically for a short period of time and also respire anaerobically for a short period of time, ie sprinting). The fast twitch muscle fibres, trained in high intesity workouts, have a main storage fuel of glycogen, whereas slow twitch fibres have a main storage fuel of triglycerides - fat. So a light intensity long run would be best. Although the fitter you get the longer and harder you can run at aerobic rates. To conclude then, do a long period of simple aerobic excercise, ie jogging or skipping, then do some high intensity sprinting so you can push harder on the aerobics next time.