We took to the streets of New York City to capture the trend that's killing the traditional fashion market

Americans have changed the way that they dress, and it's killing the traditional fashion market.

Athleisure - the trend of wearing activewear in everyday life - has been popular since the 2010s, but it continues to sweep the nation.

According to The NPD Group, US activewear apparel sales totaled $45.9 billion in 2016, up 11% from 2015 and far outperforming the traditional apparel sector overall.

Ever since athletic brands Lululemon, Under Armour, and Nike initiated the trend, other retailers such as Gap, J.Crew, and Forever 21 have jumped on the bandwagon in the hopes of boosting sales.

We headed out onto the streets of New York's Flatiron neighborhood to find out why these clothes are so popular and whether people really do wear athletic wear all day, every day.