I must add to this that I'm a bit overweight, since I don't do any upper body training. I have a BMI of 28 with strong muscles in the legs and probably a good h

I must add to this that I'm a bit overweight, since I don't do any upper body training. I have a BMI of 28 with strong muscles in the legs and probably a good heart, but a lot of belly fat. My HRmax is usually a bit below 180, but definitely above 175, so I'm in anaerobic mode at above 145, where 150 to 160 is what I usually aim for, tending towards the lower limit. My theory is that at this point I'm somehow just taking the energy out of the body fat, but I'm probably very wrong with this assumption.