These are two words that are often used interchangeably as are fitness wear and workout clothes. Sportswear are usually clothes that are specifically designed and tailored for a specific sport such as tennis, running, cycling or crossfit, whereas activewear can be worn more casually outdoors for general purposes. Likewise, athleisure is often used interchangeably with fitness fashion or leisurewear, clothes that are comfortable and more versatile because they can be worn around the house but also casually outside.