There are many opinions on age. You can't do this, you shouldn't do that. At 16 you are too young, at 60 you are too old, in between you should act as an adult. So when IS your time? The way we see it, we are OK for anything - at anytime!
Medical research shows that the average male physical peak performance is in his late twenties, female in mid-thirties. This is - if you don't do anything about it. Because research also proves that people caring for their bodies with proper lifestyle, nutrition and training, maintain near peak performance levels throughout their entire lives!
We started climbing at 32 and summited Everest at 40. We have trained Karate with men 50 years old and strong as grizzlies. We've been by- passed on the mountains by climbers 60+ of age, crossed the Atlantic ocean in a small sailing boat, just to get greeted on the other side by a tough 70+ female aboard her boat. If you think that you are too old for everything at 35 - think again.
It's never too late, you can accomplish everything you want - as long as you put some work into it. Of course you could still die at 50. But by then you will have lived at your very best to the end. And filled your life to the brim similar of a 100-year old!
So no matter how old you are - if you dream to climb Everest, the time is now. The oldest Everest-climber we have met was 62 years. He looked forty and acted forty.
No excuses. Just do it.