I'm already losing weight in this pre-op diet and I want to avoid any hangy skin...Did anyone run while on liquids? I dont wanna pass out or anything...

Running is not going to keep your skin from hanging. You should talk to your doctor about the running. Sure you could try it but obviously stop if you become woozy or aything. Walking is probably a better option at this stage though.

I reckon I'd run out of fuel in the tank.

I can run without Breakfast on a weekend morning, I usually try to do a long run of 10kms or so then. But I struggle with nothing in my stomach, I hit a wall at about 6kms, where I just plain run out of energy.

If I'd been on a liquid diet for days or weeks, I think I'd simply run out of energy.

I dont have hanging skin after my weight loss, but I do have "some" loose skin, as in, its definitely not in the condition it would have been had I never got fat and never had 3 babies. But I can tell you I dont think running has influenced that. What running has done for me is that IF I elected ever to do anything about it, I most definitely would not require a full tummy tuck with muscle repair. I have abs of steel, a perfectly flat abdominal wall, its just that there's a bit of smooshy skin over the top of it that creates a tiny bulge.

Regardless of what people say about long sessions of cardio burning your muscle, I have built tons of muscle on my body and look absolutely unrecogniseable from when I weighted 73kg at 28. Entirely different body shape, much better!

But truly, there's time for that when you're eating again. I'd walk at this stage.