The Garmin Venu ($400) is a sleek smartwatch that tracks more than activity. You can get readings for your stress and energy levels as well as how you're breathing throughout the day. It comes with preloaded workouts you can view on the screen and has the option to download music to the watch, so you don't need to bring your phone along for workouts. Our reviewer says, "It can be difficult to find watches and bands that fit my eight-inch wrist while not cutting off my circulation. I've worn this watch during HIIT class and it doesn't budge as it accurately records my vitals." Best of all, the battery lasts up to 10 days on one charge.