Example actions: working out, taking an ice bath, cleaning your house, admitting when you are wrong.
These things are not difficult to actually do, but are often described as hard, when in reality they are things that go against your instincts, so your brain tries to convince you to not do them due to instincts like conservation of energy, ego protection, etc.
The best word I have for this is just “a thing that requires mental discipline”. I am looking for something like non-instinctive, but with an additional clause of not actually being difficult to do. Or when the only barrier to doing a simple task is your own instincts. Does this word exist?
Example usage: “I need to go work out, but I am reluctant to do so because it is really ____.”