
Her response depends on genes, training program, nutrition, discipline, adequate sleep, adequate rest, etc.
Here’s an excerpt from an interview with author David Epstein in Outside online. Epstein wrote The Sports Gene: Inside the Science Of Extraordinary Athletic Performance:
Interviewer: That’s one of the most fascinating and unexpected parts of the book, where you discuss the Heritage study’s findings on trainability. Explain its implications.
Epstein: That’s the most famous exercise-genetics study ever done. It’s the collaboration of five colleges in the U.S. and Canada. They took sedentary, two-generation families, which didn’t have a training history, and put them through stationary-bike exercise plans that were totally controlled. Families had to go into the lab and exercise over five months. The goal was to see how people would improve, and they were split into four different university centers to do the training and every center saw the exact same pattern. About 15% of people improved their aerobic capacity very little or not at all. And 15% improved 50% or more doing identical training. Families tended to stick together in the improvement curve, so about half of any person’s improvement was determined by their parents. I remember the editorial that ran in the journal of applied physiology “some people’s alphabet soup—meaning their DNA—didn’t spell ‘runner.’” One person training the exact same as another person can have completely different outcomes.
Many folks don’t like to admit this, assuming it’s true. “Set your mind to it, work hard—10,000 hours—and you can do or be anything you want.” Have you ever been tortured by unrealistic expectations? The truth will set you free.