I marvel at people that sometimes show up to the comedy dojo sessions thinking I can whip them into shape to be a stand up comic.
Sorry to say this is not a sport, the 'training' is mostly internal and in your mind rather than pushups, jumping jacks and depriving yourself of carbs.
The obstacle course you'll be expected to work thru in the dojo is in your soul and sense of humor.
There are certain things that are common to the art and I can help get them out of your way quickly, that includes me after a certain time.
Not that all this won't call for some stamina and stamina building, but the endurance you will have to improve upon is taking the heat of an audience and unsolicited critiques from... well, everybody.
Your strength will be measured in confidence and faith of your vision and growing abilities. Your muscle is measured in beginning to really grasp and own your story thereby gaining momentum with your writing and stage character.
Then everything comes at the speed of spotlight. See what I did there?