My Oura Ring tracks my movement and rest across the day, and it is subtle enough to wear on any occasion.Rachel HosieThe Oura Ring is a fitness tracker popular among athletes, business execs, and celebrities.Fitness reporter Rachel Hosie has used one for four years and was originally attracted by its look.Oura ``Rings provide sleep data, step counts, and menstrual cycle tracking.When I first learned about a new fitness-tracking smart ring four years ago, it wasn't the promise of high-tech features that most piqued my interest, it was the look.As someone who enjoys both fashion and fitness, I didn't think the wrist-worn devices I'd encountered as a health reporter, such as the Whoop strap, Apple Watch, and Fitbit, were attractive enough for me to wear all day every day, to everything from the gym to a wedding.But the Oura Ring, which just looks like a chunky band (mine is gold but other colors are available), was different.Four years later, the look is still important to me, but it's the increasingly clever features that mean I still wear an Oura Ring.Launched in 2013, the Oura ring's popularity has soared in recent years and can be spotted on the hands of athletes, business execs, and celebrities.