By redirecting your thoughts, you can begin to train your brain to consider the burn you feel as a positive experience. Personally, it's never a chore to do weighted Russian twists: the burn is so good, you know it's worth every minute of effort. The shift from “‘this is good for me’ to ‘I’m dreading this last set,’ won’t happen overnight, but keep at it. Eventually, brain chemistry will begin to kick in, and you’ll relish pushing your physical limits.