What is the speaker’d main topic?

W: Well, Mr. Steve, we have had an interesting discussion about your work. Now, tell us something about your after work activities.
M: I guess not much different from everyone else. I' m fond of sports, and I run about 3 miles every day. I particularly enjoy cross-country run-ning, where you have to run across fields, jump over streams and so on. While I' m running I think about all kinds of things, and I can be-come more healthy. Next year I' m going to try the London Marathon.
It' s a long, hard race--26 miles, or 42 kilometers and you have to be tough to finish, but I want to do it very much. I worry a bit about get-ling old, and I' d like to prove to myself that I' m still almost as well as I was twenty years ago. I' m interested in climbing as well as running.
I' II never become an expert climber, but I know what I' m doing in the mountains. I successfully completed a course in snow and ice climbing when I was younger, and I' ve done a lot of easy climbs in the Alps during the last few years. My wife doesn' t share my interest in mountains. She agreed to go climbing with me once, but she found that she felt sick as soon as she reached above 1,000 meters, so we decided
to follow different hobbies.
W: You certainly seem to enjoy various types of recreation. All fight, Mr.Smith. Thanks for your interesting talk.