When you're completing a round of sprints or jump squats during a HIIT session, you don't want ill-suited workout clothes taking you out of your zone. Before you head to a class or log on to stream a class, you're smart to suit up in gear designed for high-intensity workouts.

You may want to opt for a higher neckline, too. "As a girl that has a bigger sized chest, when doing a HIIT workout, I avoid wearing low V-cut sports bras," says DanceBody master trainer Ris Finazzo. "The last thing I want is my chest spilling out of my top." Similarly, high-waisted leggings or shorts are less likely to slide down, she notes.