Okay, so Americans may not be working out, but it seems we want to dress as if we're doing that and nick watt takes a look at this phenomenon. Reporter: The fabric of this country is changing. It's... See More
Okay, so Americans may not be working out, but it seems we want to dress as if we're doing that and nick watt takes a look at this phenomenon. Reporter: The fabric of this country is changing. It's now stretchy. I wouldn't be able to do this or this. Reporter: And those pants -- You know what I'm saying, nick? Reporter: This is note at leisure clothing began with the yoga pant. Do you wear them in your Normal life too? Occasionally. To run errands. Reporter: Which means all the time. Yes. Reporter: Denim has been the go to in the staple when it comes to everyday wear but yoga pants have taken over. Reporter: Comfortable. You can dress them up. Dress them down. Absolutely. Reporter: I like them. So are we wearing more sports wear because we're exercising more? No, the number of people doing yoga rose 4.5% but clothing rose a staggering 45%. Would you work out in those pants. Yeah, I think so. Reporter: But you haven't? No, I haven't. Reporter: Underarmour is expecting 29% growth. 30 new let thathleta stores are opening and they're fakers. Not really yoga people. But yoga is about embracing everybody. Reporter: You can tell who dozen yoga, they wear the pants but also carry a mat. For "Good morning America," nick watt, ABC news, Santa Monica.
This transcript has been automatically generated and may not be 100% accurate.