David Roeske, a guest on episode 235, shared how he manages to train for big mountains with just the simple tools he has at sea level. He cuts out other things and focuses on his demanding job and athletic goals. He listens to books and podcasts while on the treadmill, which feeds his brain and is useful for his job. He also runs up stairs instead of taking the elevator.
In episode 396, Dr. Anders Ericsson discussed the idea that innate talent is not necessarily real. He found no evidence that you have to be born with certain genes to achieve high performance. Virtually everything else can be improved with known training methods. Some changes can only happen when you're in development, such as ballet dancers turning out their feet more than normal people.
In terms of physical attributes, height and body size are not something that you can train, but being short is a major advantage in artistic gymnastics.
Overall, it seems that with the right training methods and dedication