. >> and there's my friend and nasa astronaut, sa nita williams, spacewalking like a pro last week. but, you know, she's got another challenge ahead of her this weekend as well. she's decided to raese the triathlon from space. i spoke with her earlier and asked her to show me how she's, in fact, going manage that bike ride. >> sure. i was talking about the bike when you were visiting us before because luckily here in space we don't need a seat. all we do is put our feet in the pedals. i'll demonstrate here. we have a computer to dial in the resistance and speed and also just for health purposes take our heart rate as we're riding so we can -- this is how i'm going to simulate the bike ride. sore if the hills, i can increase my my resistance to match the root that you're going to talk because i would assume that malibu is not flat like houston, right? >> not flat at all. she's absolutely right about that. now, about the course out here. i want to give you a sense of what we're up against. we'll give you a sneak peek with cnn fitness producer. >> reporter: look at those choppy waves,