Choose one exercise for each of the following four categories:
<ul>
<li>P- Plyometric cardio (e.g., Jumping Jacks)</li>
<li>A- Abs (e.g., Plank)</li>
<li>U- Upper Body (e.g., Push-Ups)</li>
<li>L- Lower Body (e.g., Squats</li>
</ul>
Perform each exercise for 30 seconds. After performing all four exercises, rest 30 seconds and start again

The P.A.U.L. method (10 minutes)

<ul>
<li>Jumping Jacks: 20 reps or 40 reps</li>
<li>Squat: 10 reps or 20 reps</li>
<li>Incline push-up: 10 seconds or 20 seconds</li>
<li>Plank: 30 seconds or 40 seconds</li>
<li>Single-Leg Glute Bridge: 5 reps each leg or 10 reps each leg</li>
</ul>
Complete this circuit three times with a 30-second rest between each round.

A HIIT circuit (beginners and advanced)

<ul>
<li>40 Speed Skaters</li>
<li>10 Floor Burpees</li>
<li>15 Leg Lift + Hip Lift</li>
</ul>
Set a timer for 10 minutes and complete the circuit as many times as possible with little to no rest over the course of those 10 minutes.

The 3-HIIT wonder (10 minutes)

<ul>
<li>Star Jumps (30 seconds): a dynamic exercise that targets legs, glutes, core, shoulders, and cardio.</li>
<li>Squat Jumps (30 seconds): a dynamic exercise that targets the legs, glutes, and core.</li>
<li>Close Grip Push-Ups (30 seconds): this targets your chest, shoulders, and core.</li>
<li>Reverse Crunches (30 seconds): this targets the lower abs but will require the entire core to be involved.</li>
<li>Toe Touches (30 seconds): it targets your upper abs.</li>
<li>Burpees (30 seconds): this targets legs, glutes, core, shoulders, and cardio.</li>
</ul>

The perfect HIIT workout

<div>

<ul>
	<li>High-intensity-interval-training or <a href="http://www.insider.com/what-is-hiit-2018-2">HIIT</a> is a popular workout you can do at home, without equipment.</li>
	<li><a href="http://www.insider.com/how-to-get-rid-of-stomach-fat-2017-8">HIIT</a> scorches calories in a short amount of time.</li>
	<li>HIIT circuits increase your heart rate and tighten and tone your muscles.</li>
</ul>

 If you're looking for a workout you can do at home that takes less than 20-minutes, then you might want to consider high-intensity-interval-training or HIIT. 
Interval training (HIIT) uses bouts of high-intensity exercise alternated with short rest periods to <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5819474/"> maximize calorie burn and cardiorespiratory fitness </a> in half the time of slow-steady state cardio. 
INSIDER asked four fitness experts that specialize in designing HIIT workouts to share one of their favorite routines that you can do at home. 
<h3>The P.A.U.L. method</h3>
<figure> <img src="https://i.insider.com/5a2b08bf3339b023088b4589?width=600&amp;format=jpeg&amp;auto=webp"></figure> Certified personal trainer, <a href="http://www.fit2gopt.com"> Dani Singer, </a> told INSIDER that he created the P.A.U.L method for people who want a quick 10-minute workout they can do at home. Here's how it works: 
<ul>
	<li>Choose one exercise for each of the following four categories: </li>
	<li>Set a timer to beep every 30 seconds, or use an <a href="http://www.online-stopwatch.com/interval-timer/">online interval timer </a>. </li>
	<li>Perform each exercise for 30 seconds, switching every time you hear the timer beep. </li>
	<li>After performing all four exercises, rest 30 seconds and start again. Continue with this circuit until you've reached 10 minutes. </li>
</ul> 
<h3>A HIIT circuit for both beginners and advanced</h3>
<figure> <img src="https://i.insider.com/5a32d2a0e7940120008b46b5?width=600&amp;format=jpeg&amp;auto=webp"></figure> Certified personal trainer, Geoff Tripp, head of fitness at , shared this HIIT workout with INSIDER: 
Beginners can stick with the lower number of reps, while more advanced exercisers can opt for the higher numbers. Complete this circuit three times with a 30-second rest between each round. 
<ul>
	<li>Jumping Jacks: 20 reps or 40 reps </li>
	<li>Squat: 10 reps or 20 reps </li>
	<li>Incline push-up: 10 seconds or 20 seconds </li>
	<li>Plank: 30 seconds or 40 seconds </li>
	<li>Single-Leg Glute Bridge: 5 reps each leg or 10 reps each leg </li>
</ul> 
<h3>The 3-HIIT wonder</h3>
<figure> <img src="https://i.insider.com/5b3e65ebc8d6ed39008b45e8?width=600&amp;format=jpeg&amp;auto=webp"></figure> Certified personal trainer and Gold's Gym fitness expert, <a href="http://dempseyfit.com/about/"> Dempsey Marks </a>, created a HIIT workout for INSIDER that you can do at home in just 10 minutes. 
Instructions: Set a timer for 10 minutes and complete the circuit as many times as possible with little to no rest over the course of those 10 minutes. 
40 Speed Skaters Begin standing with your feet hip-width apart. Engage your core and jump to the right, landing on your right foot, crossing your left leg behind you diagonally. Allow your left arm to swing across your body and your right arm to swing behind you. Upon landing, jump immediately to the left and switch your arms and legs. 
10 Floor Burpees Begin standing with your feet shoulder width (or slightly wider), arms at your sides. Bend your knees and squat down, placing your hands on the floor (shoulder width or slightly wider). Jump your legs back, landing in a plank position. Your body should be a straight line from the crown of your head to your toes). Keeping your core engaged, lower your entire body to the ground. Press through your palms and toes to return to a plank position. Jump your feet back up to your hands. Explosively jump upwards, reaching your hands straight up and land softly in the starting position. 
15 Leg Lift + Hip Lift Begin lying on your back with your hands under your hips. Press your lower back into the ground. Bring your legs straight up and down. Keeping your legs straight and ankles together, lower them until they're about 2-3 inches off the ground. Pause and return to starting position. Then, push your heels straight up like you're making an impression of your footprint on the ceiling. 
<h3>6 exercises for the perfect HIIT workout</h3>
<figure> <img src="https://i.insider.com/592352d82b0202516a8b45de?width=600&amp;format=jpeg&amp;auto=webp"></figure> Certified personal trainer, Keith Stafford MS, NASM, CPT, <a href="http://www.fitbodybootcamp.com/">Fit Body Boot Camp </a> owner, shared his top HIIT exercises with INSIDER. 
Star Jumps Stand with your feet shoulder-width apart, bend your knees and lower your hands down to the ground, jump up with as much explosive power as possible raising your hands overhead and outward and spreading your feet apart. While in the air, you should look like an X. Be sure to land with your legs back at shoulder-width apart and on the balls of your feet. Immediately bend your knees, lower your hands to the ground and repeat for 30 seconds. The star jump is a dynamic exercise that targets legs, glutes, core, shoulders, and cardio. 
Squat Jumps Stand with your feet shoulder-width apart, bend your knees and push your butt back as if sitting in a chair. Focus on keeping your weight on your heels, not your toes. Keep your back as straight as possible with your chin in a neutral position. When your upper legs are even with the ground, explode upward. Be sure to land on the balls of your feet, then shift your weight to your heels and repeat the squat jump for 30 seconds. Squat Jumps are a dynamic exercise that targets the legs, glutes, and core. This exercise can include weights like dumbbells to increase resistance and build additional lean muscle mass. 
Close Grip Push-Ups Start in a plank position. Hands on the ground, placed inside your shoulders (your hands may even be touching), body straight from your shoulders to your toes. Bend your elbows, allowing them to go backward (not outward) until your chest touches your hands, then push back up. Repeat for 30 seconds. Close grip push-ups are a great modification to the standard push-up. The close grip push-up targets your chest, shoulders, and core. 
Reverse Crunches Lay on your back with hands to your sides and legs straight. Start with your heels a few inches off the ground. Keep your legs straight and raise them until they are vertical. Once they are vertical, raise your feet towards the sky bringing your hips off the ground. Return your hips to the ground, lower your straight legs to the starting position a few inches off the ground and repeat for 30 seconds. The reverse crunch targets the lower abs but will require the entire core to be involved. 
Toe Touches Lay on your back and lift your legs until vertical. Raise your upper body off the floor reaching to your toes with your fingers, then lower your upper body back to the floor. Keep tension in your core by not allowing your back to come all the way to the floor. Repeat for 30 seconds. Toe Touches are an excellent core exercise the targets your upper abs. 
Burpees Start in the standing position with feet about shoulder-width apart. Bend your knees and place your hands on the ground shoulder width apart. Kick your legs back until fully extended and you're in a plank position. Immediately jump your feet back to the original position and jump upward raising your hands towards the sky. Repeat for 30 secs. Burpees are one of the best exercises around. They target legs, glutes, core, shoulders, and cardio. Add in a push-up (Burpee Push-up) when in the plank position and you also target chest and arms. 
</div>

Chances are you've heard about the fitness phenomenon, HIIT. And for good reason - the tough workout promises toned muscles and intense fat burning in a matter of minutes. The best part is, you don't have to leave your house to get its benefits.

HIIT workouts you can do from the comfort of your own home

The P.A.U.L. method (10 minutes)

A HIIT circuit (beginners and advanced)

The 3-HIIT wonder (10 minutes)

The perfect HIIT workout

It's time to
Read like a Pro.

The 7-Minute Workout

The 8 Best Strength-Training Exercises for Beginners

Best calisthenics home workout: 5 exercises and almost no equipment can get you ripped

HIIT workouts you can do from the comfort of your own home

The P.A.U.L. method (10 minutes)

A HIIT circuit (beginners and advanced)

The 3-HIIT wonder (10 minutes)

The perfect HIIT workout

It's time to Read like a Pro.

The 7-Minute Workout

The 8 Best Strength-Training Exercises for Beginners

Best calisthenics home workout: 5 exercises and almost no equipment can get you ripped

It's time to
Read like a Pro.