I once read that 40% of the population is "immune to exercise" and I suspect I'm one of the 0.40.

.4 of the population unlikely to have evolved? I can't take this too seriously I suppose.

Did you try working on strength first? A lot of cardio is claimed to not be very helpful.

Also, consider a coach or a fellow rationalist with some domain knowledge to work with, it's pretty important to optimize this area (esp. if it puts you out of commission for the rest of the day).

One hack that helped me work throughout the annoyance is reading kindle on a stationary bike. Lost 20 with that trick.