If you are short on time but want to get in a good heart-pumping, muscle-building workout, HIIT [1] (high-intensity interval training) is where it's at. These workouts will not only burn calories, but they're also proven to diminish belly fat [2].

This 15-minute HIIT cardio workout involves five basic bodyweight moves [3], many of which are plyometric (requiring jumping) and high-impact. (You can always modify the moves or work for shorter intervals if you're new to this style of training.) "This workout is not for the faint-hearted," said Danyele Wilson [4], a NASM-certified personal trainer with Tone & Sculpt [5]. She created this efficient routine, which can help you improve endurance and burn calories in a short amount of time.

If you're ready to sweat, grab your water bottle and let's get started!

Related:

Start Our 30-Day Beginner Bodyweight Challenge Today and Get Stronger Every Day! [6]

15-Minute HIIT Workout

Directions: Start by foam rolling your calves, quads, glutes, and hamstrings, and complete the dynamic warmup below. Then begin the workout, completing 30 seconds of each exercise below, followed by a 30-second rest before moving on to the next exercise. When you finish the last exercise, rest for 30 seconds and go back to the start, repeating the circuit for three rounds. After the third round, cool down with the stretches below.

Related:

A 30-Day Squat Challenge to Put Your Lower Body to the Test [7]

Warmup, Exercise 1: Standing Knee Hug

• Start standing with your feet together and your arms at your sides. Pull your core in toward your spine, and keep your chest lifted.
• Lift your right leg and bend it, bringing your knee into your chest with control. Clasp your hands around your knee or shin to hug it as close to your chest as you can.
• Set your right leg back down, and repeat on your left leg.
• This counts as one rep. Continue alternating legs for 30 seconds while maintaining proper form.

Warmup, Exercise 2: Hamstring Scoop

• Stand with your legs hip-width apart, and step your right foot slightly forward. Flex your right foot so the edge of your heel is on the ground and your toes are off.
• Bend at your hips and left knee to bring both arms down, keeping them close to your body. In one fluid motion, "scoop" them down your right leg down to your ankle. Keep your right leg straight throughout while bending into your right knee. You should feel the stretch in your right hamstring.
• Continue the scooping motion as you straighten your right leg, raising your arms out in front of you and overhead.
• Step your right foot back to the starting position, then repeat on the other side.
• This counts as one rep. Continue alternating legs for 30 seconds while maintaining proper form..

Warmup, Exercise 3: Standing Quad Stretch

• Stand on your right leg with your knees touching. If you need to, grab hold of a chair or wall for support.
• Grab your left foot with your left hand and pull your heel toward your butt. Do your best to keep your chest upright, and don't worry about how close your foot is to your butt. Focus on the stretch on your left quad.
• Hold for 30 seconds, then switch legs.

Warmup, Exercise 4: Plank Walkout

• Stand at the back of your mat, and circle your arms out to the sides to reach toward the ceiling. Look up, and feel your chest opening up.
• Keeping your back straight, bend forward from your hips to bring your hands to the mat. This position should stretch your hamstrings. If they're tight, bend your knees a bit to take tension off your muscles.
• Walk your hands forward until your shoulders are directly over your wrists, coming into a high plank. As you walk forward, hold each step to stretch your calves and warm up your shoulders and hands.
• Hold the plank for a few seconds, pulling your core in toward your spine and keeping your torso in a straight line from shoulders to ankles.
• From your plank, walk your hands back to your feet until you are in a forward fold, bending from your hips with your hands dangling down.
• Slowly roll up until you're standing, letting your head hang and keeping your neck relaxed. Roll all the way up until you're fully upright in the starting position.
• This counts as one rep. Continue for 30 seconds while maintaining proper form.

Warmup, Exercise 5: Alternating Lateral Squat

• Stand with your feet wider than hip-width apart and your arms by your sides. Pull your core in toward your spine and brace it, keeping it engaged throughout the movement.
• Bend at your right hip and knee to lower into a lateral squat, ensuring your right knees remains in line with your toes. Keep your left leg straight and both feet flat on the floor. As you squat, bend your arms to lift your hands to your chest and continue looking straight ahead, keeping your core tight and chest lifted.
• Drive through your right heel to straighten your right leg and return to the starting position.
• Repeat on the other side.
• This counts as one rep. Continue alternating sides for 30 seconds while maintaining proper form.

Warmup, Exercise 6: Dead Bug

• Lie on your back with your arms extended directly in front of your chest and your palms facing toward your feet. Bend your knees, and bring your legs into tabletop position, ensuring your knees are stacked over your hips and your shins are parallel (in line with) the floor. This is your starting position.
• On an exhale, draw your ribs to your hips to engage your core. Draw your left arm back and down toward the floor alongside your head. At the same time, extend your right knee and hip to lower your right leg toward the floor. Ensure that your arm and leg are lowering at the same speed and that you maintain a neutral spine.
• On an inhale, raise your left arm and right leg to return to the starting position.
• This counts as one rep. Continue alternating sides for 30 seconds while maintaining proper form.

Warmup, Exercise 7: Glute Bridge

• Start lying on your back with your knees bent and feet flat on the floor. Be sure to keep your feet underneath your knees, not in front. Plant your palms by each side, facing down.
• Press through your heels to raise your hips up to the ceiling, tensing your abs and squeezing your butt as you do. You should be making a long diagonal line with your body, from shoulders to knees.
• Hold for a few seconds, making sure your spine doesn't round and your hips don't sag. Keep your abs and butt muscles engaged.
• Lower down to the ground.
• This counts as one rep. Continue for 30 seconds while maintaining proper form.

Warmup, Exercise 8: Jumping Jack

• Start standing with your feet hip-width apart, arms by your sides, and core pulled in toward your spine.
• Jump both feet out to the sides while simultaneously swinging your arms out to the sides and overhead. Land softly with your feet wider than hip-width apart, and make sure to keep your core braced throughout the exercise.
• Jump your feet back to hip-width while swinging your arms back down to your sides, landing softly as you come back to the starting position.
• This counts as one rep. Continue for 30 seconds while maintaining proper form.

Alternating Lateral Lunge to Squat Jump

• Start standing with your knees slightly wider than hips-width apart.
• With your right foot, take a wide step out to the right.
• Looking straight ahead, bend at your hips and right knee, ensuring your knee remains in line with your toes. Keep your core pulled in toward your spine and your chest lifted. Let your left leg extend straight as you lunge to the right.
• Drive through your right foot to step back to the center, continuing to bend at your knees and hips so you're in a standard squat position.
• From the squat, jump off the floor in a quick, explosive movement, swinging your arms behind you for momentum. Remember to keep your core braced and chest lifted, squeezing your glutes at the height of your jump to push your hips forward.
• Land softly, returning to the center squat position.
• Repeat on the other side.
• This counts as one rep. Do as many reps as you can in 30 seconds while maintaining proper form.

Alternating Quick Switch to Drop Lunge

• Start standing with your feet hip-width apart, arms by your sides.
• Quickly jump your right foot forward and your left foot back, swinging your arms in a running motion and keeping your core pulled in. Land softly.
• Immediately jump your feet again, this time bringing your left foot forward and right foot back.
• Switch your feet one last time, so your right foot is again in the front and left foot back. This time, land softly in a lunge position, bending at your right knee in a 90-degree angle and lowering until your right thigh is parallel with the ground. Your right knee should be in line with your toes.
• Drive through your feet to come back to standing.
• Repeat, switching your feet so you lunge with your left foot forward.
• This counts as one rep. Do as many reps as you can in 30 seconds while maintaining proper form.

Broad Jump Burpee to Back Pedal

• Start standing with your feet hip-width apart, core pulled in toward your spine.
• With controlled force, throw your arms overhead and bend at your hips and knees to come into a shallow squat.
• Swiftly bring your arms down, then thrust them up again and jump forward as far as you can so you land about four or five feet in front of your starting position. Land softly, bending your knees to absorb the impact and continuing to brace and engage your core.
• Squat as deeply as you can, keeping your knees in line with your toes, and place your hands on the ground.
• Kick your legs back so you land in a high plank position, shoulders over your wrists and body in a straight line.
• Lower your body all the way to the ground, bending your elbows out to the side at a 45-degree angle and keeping your body in a straight line as you lower it.
• Push through your hands to lift back up into a plank position.
• Jump your feet forward, landing softly on either side of your hands to come into a low squat.
• Stand upright and shuffle back to the starting position, using short, quick steps and keeping your hands out in front of you.
• This counts as one rep. Do as many reps as you can in 30 seconds while maintaining proper form.

Treadmill Sprint or Sprint in Place

• If you have a treadmill, step on and increase the speed to your sprinting pace. Run for 30 seconds. (For added intensity, increase the incline on the treadmill.)
• If you don't have a treadmill, sprint in place, landing softly on each step and pumping your arms. Continue for 30 seconds.

Drop Squat

• Stand with your feet slightly wider than your shoulders, feet parallel or toes slightly turned out, and arms at your sides.
• Jump your feet out as you lower into a squat by bending at your knees and hips. At the same time, bring your left hand in front of you, making contact with the ground. Your right arm should be relaxed, behind your back. As you lower down, keep your core pulled in toward your spine and your chest lifted; your spine should stay straight, not slump, as you reach for the ground.
• Jump your feet back in, returning to the starting position with your hands touching in front of your chest. This counts as one rep.
• Do as many reps as you can in 30 seconds, alternating sides, while maintaining proper form.

Cooldown, Exercise 1: Downward Dog With Heel Lift

• Begin on your hands and knees, with your shoulders over your wrists and your hips over your knees.
• Inhale as you tuck your toes under your heels. Then exhale to lift your hips, coming into an upside-down V shape called Downward Facing Dog.
• Spread your fingers wide, and create a straight line between your middle fingers and elbows, letting your heels drop toward the ground. Relax your head between your arms, and direct your gaze through your legs or up toward your belly button.
• Press your left heel toward the ground, and bend your right knee, concentrating the stretch in the back of your left leg.
• Hold for a few seconds, then switch sides, pressing your right heel to the ground and bending your left leg.
• Continue switching back and forth for 30 seconds.

Cooldown, Exercise 2: Lying Spinal Twist

• Start lying flat on your back, and draw your right leg in toward your chest.
• Use your left hand to gently push your right knee across your body, twisting your spine in the opposite direction as you do.
• Extend your arms into a T position, and turn your head to the left.
• Hold here for 30 seconds, feeling your spine lengthen and twist. You may even hear some "cracks."
• Roll gently back onto your back, keeping your right knee bent into your chest. Slowly straighten and lower it to the ground.
• Repeat the sequence on your left leg, again holding the stretch for 30 seconds.

Cooldown, Exercise 3: Cobra Pose to Child's Pose

• Lie on your stomach with your legs straight behind you. Place your palms on the ground by your armpits, elbows bent behind you.
• Push through your hands to slowly lift your head and shoulders off the ground, arching your back while keeping your hips and thighs on the ground. Arch back as far as is comfortable, keeping your elbows slightly bent to lessen the stretch and straightening them to intensify it.
• Actively roll your shoulders back and down away from your ears, elongating your neck. Keep looking in front of you, or if you want more of a chest stretch, drop your head back between your shoulder blades. Stay here for a few breaths.
• Slowly lift your hips and shift your butt back until it rests on your heels, bowing your back and coming into Child's Pose. Your arms should be straight out in front of you, palms pressing into the ground. Stay here for a few breaths.
• Lift your hips again and shift forward to return to Cobra Pose.
• Move slowly between the two poses for 30 seconds.

Cooldown, Exercise 4: Standing Forward Fold With Clasped Elbows

• Begin standing with your feet hip-width apart, arms at your sides.
• Take a breath in, and as you exhale, bend at your hips, folding over your thighs. Keep your back as straight as you can, initiating the bend from your hips and waist.
• Bend your arms, and take hold of your opposite elbows, holding your right elbow in your left hand and your left elbow in your right hand.
• Keep your weight pressing forward, feeling the stretch in your lower back and hamstrings. Gently sway your torso, and nod and shake your head to release tension in your neck.
• Hold for 30 seconds.