jrock645- I gather I didn`t give offense yesterday..I`d been wondering about how I came across and..Oh Boy can I sound like a know-it-all windbag
My wife and I were discussing this last night...back when I did longer/less intense sessions on the StairMaster I got my HR up to about 160 or so. Tough enough that I worked up a good sweat and felt I`d done a good workout, easy enough that I didn`t mind/dread it. So I really do know where you`re coming from...But that simply wasn`t the right thing for me to do and as I got older I had to quit doing ineffective stuff.
Speaking of "not the right..", I`d sure avoid anything that messes you up! I can`t run sprints or jog much so I simply gave up on that stuff and now I play to my strengths, namely stuff that`s really hard but doesn`t injure me. Like, I can have some fun on an elliptical, but eh..not a real workout for me anyhow so I`d rather take the dogs for a hike in steep terrain.
Anyhoo...FWIW I`d see about doing the HIIT on the bike; they used adjustable-resistance stationary bikes in the original Tabata study, adjusting the resistance so the trainees could barely maintain ~85rpms during the work intervals and they`d end the session if the rpms dropped below 80.
BUT...yes indeed, the burnout/aversion factor! The only exercise that`s really effective is what you`ll keep doing.
BI do think that if you really, REALLY spike your HR you oughta get good fat burning for a long time, MUCH longer than if you did less demanding work (which burns more during the excercise, but quits doing it shortly thereafter).
(Eh, I wish I`d archived the studies that convinced me instead of just reading them. I`d really like to back up what I`m sayin` with some hard data. You can find them..eventually...by reading all the stuff on the websites for Clarence Bass, Dick Winnett, and uhm...Mercola, but from those you still gotta go find the actual studies and pore through the data..heap big research project.)
Heh heh...repeat my advice to ignore the scale

and keep doing the ~150 bpm work to keep your arteries OK. Just figure out a way to do harder work for the fat burning.
I`ve had what I considered "loose skin" in that Love Handle area since I was a kid, so I sympathize. I made progress (finally) by working my obliques hard/frequently enough to keep them slightly overtrained. You know how "spot reduction is a myth?", well...note those scare-quotes. Recent advances in being able to track stuff on the cellular level implies differently, and perhaps it`s just coincidental but ever since I figured out good exercises for my Obliques and started doing them more often, I`ve tightened up that area quite nicely, guess it wasn`t all just loose skin after all! The oblique work is the only time I do really high reps, and it took a few months to be able to do many at all as the effective exercises were (?are?) very difficult for me. I`d been doing [crap] like side-bends or improper trunk-twists forever, but never realized they weren`t effective, thought I just wasn`t working hard enough.
EDIT: I`m assuming your diet is relatively good...trying to out-exercise a poor diet is a losing proposition long-term.