Back when gyms were allowed to open at full capacity and boutique fitness classes were like social events, Brynn Putnam, founder and CEO of Mirror, was already thinking of ways to elevate her workouts at home.

"I always felt like working out at home and you were sacrificing quality for convenience," Putnam tells CNBC Make It. "You were putting a big bike or a treadmill into your small in your apartment, or you were searching for content on YouTube and watching it on a tiny phone while you tried to awkwardly workout."