What if climbing got better over the time that you use it? Let’s say that the amount of stamina you have whilst doing the climbing trial is the base amount of stamina. I think it would be interesting if whilst you climb, you are making progress towards a longer stamina bar. To elaborate, I don’t mean making the stamina bar longer but as you climb you make progress towards a longer lasting stamina bar. Theoretically, you wouldn’t make progress towards this climbing whilst in the tower.
Basic Idea: You climb, stamina last longer. More you train it, longer your stamina lasts you.