The beauty of high-intensity interval training (HIIT) is that you’re working your heart at close to max effort (85% to 95%), so you burn a ton of calories while building superior cardiovascular strength in almost no time at all. It’s great for losing weight and improving heart health: A study in the British Journal of Sports Medicine found that people with heart disease who committed to doing several four-minute bouts of HIIT at least three times a week doubled their cardiovascular fitness level. Meanwhile, other studies have found that HIIT burns significantly more fat than steady-state activities like running while requiring less time commitment. So how exactly do you do it? Most HIIT workouts follow a pattern of 60 seconds at max effort, followed by 1-2 minutes of active rest. Active rest means slow jogging, walking, or double-bounce jump rope (if that’s your jam). The equipment-free 15-minute routine here uses a circuit of six HIIT moves. You’ll warm up for 3 minutes. Then do each move for 60 seconds, followed by 60 seconds of active rest, before launching into the next move. Repeat the circuit twice.

The Ultimate 15-Minute HIIT Circuit

Warm Up: Walk briskly around the house, stretch gently, walk up and down stairs. Fast Jacks: Aim for one second per jumping jack, 60 seconds total. Active rest: 60 seconds (walk, slow jog in place, double-bounce jump rope) High Knees: Run in place, arms raised over your head, while hiking each knee toward your chest, 60 seconds total. Active rest: 60 seconds Burpees: From a high plank position (arms straight), jump your feet forward, landing in a squat as close to your hands as possible. Push through your heels and jump straight into the air, raising arms above your head. Land in a squat, place your hands back on the ground, and hop feet back into a high plank position. Do one pushup. Repeat for 60 seconds. Active rest: 60 seconds Slalom: Stand with feet together. Bend your knees and elbows, and tuck your arms like you’re going down a ski slope. Staying in a shallow squat, jump both feet together to the right side, then jump them back over to the left. Keep alternating left/right for one minute. Active rest: 60 seconds Lunge Jumps: Start in a lunge position, front knee bent at 90 degrees, back leg straight. Shift your weight to the front leg. In one smooth move, straighten your front leg, push through the toe of your back foot, and swing back leg forward until it is front of your body, knee bent. As you do this, jump vertically in the air. Land in your original starting position. Do 20 on your right side, then 20 on your left for one minute. Active rest: 60 seconds Sprint: If you have stairs in your house, go up and down them as fast as you can for 60 seconds. No stairs? How about hallways? Or down the driveway and back. Or a sidewalk dash. Yes, you might have to leave the premise for this one, but it’s the best way to maximize the burn. Cooldown: 60 seconds (slow walking, gentle stretching)