>>2108513You should have excellent cardio and also be physically strong. Hauling a 60lb+ backpack and 60lb+ sled of gear together uphill for 6-10 hours is very hard work even at low elevation. Ideally, you should be in the best shape of your life, and you should have enough mountaineering and altitude experience to know whether or not you're ready and capable. Don't even think about a minimum cutoff - regardless of how fit you are it will still be hard, so train as hard as you can to be better. The stronger you are, the safer climbing will be.
If you have money and want a fast track to Everest:
1. Do a guided climb of a Ranier.
2. Do a guided climb of a Denali.
3. Do a guided climb of a Cho Oyu.
4. Sign up for Everest.
At that point you won't have much for magical technical skills unless you do other training, but if you're not retarded you should be able to be "safe" on something like Everest.
It's important to experience climbing yourself in a controlled a progressive manner rather than try and estimate the outcomes based on accounts you read. Each climb will teach you a lot, and you'll learn in a safer and more gradual way how altitude affects you. I have been trekking in Nepal when people were being evacuated from ~4500m due to severe altitude sickness. I have personally experienced symptoms of altitude sickness as low as 3500m due to fast ascent.
When I prepared to climb Denali, I did 12 workouts a week: 1 cardio (after work) + 1 strength (before work) per day for 6 days, then 1 rest day off. I did that for about 8 months prior to the climb, in addition to having good base fitness before that from regular but less intense exercise.
