I'm William Brangham, and this is Horizons.

The Winter Olympics are in full swing, but these games are a far cry from the first so-called

modern Olympics held in Athens 130 years ago.

Advances in training and technology and psychology have helped push athletes to the top of their games,

while rising temperatures are transforming the snow beneath the athlete's feet.

We look at some of the driving forces reshaping the modern-day Olympics.

Coming up next.

The United States. Welcome to Horizons from PBS News.

We are all caught up in Olympic fever over here, so we are going to devote a whole show to the games.

A little later, we'll look at how climate change is making it increasingly difficult

to hold the Winter Olympics, and what researchers and some athletes are doing about it. But first,

we want to talk about what's going on in the minds of these competitors. Watching these games,

it is hard not to marvel at the exquisite focus and concentration of the Olympians.

We wanted to talk with someone who could give us a glimpse into how you prepare these competitors

mentally for the stress of this enormous stage.

Psychologist Caroline Silby is the head of sports psychology and mental performance at U.S. figure skating.

She's a former competitive skater herself and now works as part of a large interdisciplinary team,

exercise physiologists, nutritionists, doctors, as well as coaches,

to help U.S. skaters perform at their peak.

I spoke with Silby earlier in between practice sessions

and competitions. Caroline Silby, thank you so much for talking with us. Will you just tell us

where are you sitting right now? I am sitting right now in Milan, Italy, and I am at the Olympic Village.

...