That HIIT workout routine is upping your cortisol (stress) levels. The head of research at Les Mills wants you to keep it under 40 minutes per week. “Cortisol is not particularly a ‘bad’ hormone, it’s ...

Perfect for all fitness levels — this 20-minute HIIT workout combines power and endurance to sculpt your body fast!

Rockstar Equinox trainer and fitness model Julie Wandzilak shares an at-home workout that'll elevate your heart rate, boost your brain power, and burn calories. The holidays might be the most ...

No time to hit the gym? No problem. A good workout doesn’t always have to take place surrounded by a ton of iron anyway (as you’ll soon discover). This 20 minute HIIT workout will not only smoke your ...

"Hearst Magazines and Yahoo may earn commission or revenue on some items through these links." Want an exercise program that helps you work out smarter, not harder? You've found it. The Women's ...

In TODAY.com's Expert Tip of the Day, a trainer explains how incorporating HIIT into a weekly workout routine can boost one's metabolism and help with weight loss.

Forget hours running on the treadmill or the elliptical machine at the gym — if you’re short on time and looking for a way to torch calories, you’re better off doing a quick HIIT workout. You don’t ...

When you hear the term HIIT (that’s high-intensity interval training), your mind might immediately jump to burpees, mountain climbers, and jump squats. That’s one definition of HIIT, sure—but on this ...

Workout trends come and go, but when it comes to the biggest bang for your buck, high intensity interval training, or HIIT, has staying power. HIIT’s specific origins are uncertain; some say it dates ...

Join instructor Sina Riemann for a 20-minute HIIT Pilates class. Riemann incorporates elements of pilates, strength training, and high-intensity cardio for a short but effective workout that's perfect ...

HIIT workouts are meant to be fast and furious. They rely on explosive exercises like burpees, high knees, kettlebell swings, sprints, and other moves that spike your heart rate and make you sweat — ...