>>202928Altitude sickness is random and it can hit people who live in Denver who are climbing a 14er. But generally, you will get some kind of livable symptom, especially coming from a low altitude - sleeplessness (if camping), loss of appetite (everything tastes like shit), headaches, water retention in body fat, general fogginess, short breath/heavy heart when exerting, etc.
Being "in shape" is kind of vague. You need to be in good shape with respect to endurance. You need to run, run, and run some more. Work in a weight routine but keep running. Powerful legs help keep the knees from blowing out on the climb but endurance is the key.
And staying hydrated can't be emphasized enough - you think you drink a lot of water now...on the climb, you need to drink lots...and be sure to work in salts (one small package of gatorade mix in a full nalgene is more than enough) - I've bonked twice with muscle lock...sucked. And the water coming out of your hydration bladder will taste like shit at altitude if the bladder has any age to it.
BTW - I live at 22-feet above sea level. Pic is summit of Wetterhorn looking kind of towards Ouray this past June...