High-intensity interval training, otherwise known as HIIT [1], can be as intense as it sounds. You're putting in maximum effort for short bursts of time and only have brief periods of rest. It's a cardio-based style of exercise that, if done consistently and with proper eating habits [2], may help you build lean muscle [3] and shed fat — belly fat specifically [4]. HIIT can also be done as a specific form of strength training (here's an example [5]), and you can use it as a way to structure your treadmill workouts [6]. You can torch calories fast and, as it turns out, burn calories even after you're done exercising due to something called the "afterburn effect," or EPOC [7]. Now, who wouldn't want that?

ISSA-certified personal trainer Melissa Kendter [8] knows that starting HIIT can be hard. So, she designed a HIIT workout that will ease you into this type of interval training. "It can be done inside, outside, while you are traveling, at home, at the gym . . . literally anywhere," Melissa told POPSUGAR. This is considered HIIT for someone who hasn't tried it before but still has athletic ability, since she incorporates some compound exercises [9]. It's low impact, has minimal rounds, and requires no added weight.

15-Minute HIIT Workout For Beginners

To warm up, do the following: 10 reps of front to back leg swings [10] on each side, 10 reps of windmill toe touch [11] on each side, five forward and five backward large arm circles [12], 10 reps of alternating knee hug [13] on each side, and 10 reps of alternating side reach [14] on each side.

Next, do each of the following exercises for 30 seconds followed by a 30-second break. Complete all five moves, then rest for one to two minutes and repeat the cycle one more time.

1. High plank: 30 seconds followed by 30 seconds of rest
2. Sumo squat to standing oblique crunch: 30 seconds followed by 30 seconds of rest
3. Mountain climber: 30 seconds followed by 30 seconds of rest
4. Alternating side lunge: 30 seconds followed by 30 seconds of rest
5. Bodyweight squat to alternating kickback: 30 seconds followed by 30 seconds of rest

Melissa doesn't want you to stand still while you're taking your breaks in between exercises and rounds. You can march in place, do slow arm circles, or just pace around the room, she said. "Studies have proven that when you move and engage in active recovery during rest periods, it actually helps dramatically reduce that burning sensation or fatigue sensation [15] that you get during the intense part of the exercises," she explained. It also keeps you from getting stiff, she said. "However, make sure you always listen to your body and know if you're pushing yourself past the breaking point."

Once you've mastered this workout — which, might we add, has a bonus of targeting your legs and core — and want to make it more difficult, you can decrease the rest periods and increase the work periods. For instance, you can do 40 seconds on, 20 seconds off. You can also add in weights for the moves other than high plank and mountain climbers, or add in more rounds (try three rounds instead of two). Ahead, check out how to do each of the five exercises before you get your sweat on!

High Plank

Melissa said a high plank targets your entire core (even your deep core like the transversus abdominis, or TVA) [16]. It also targets your back, deltoids, and legs as secondary muscles, she added.

• Start resting on all fours.
• With your palms flat, raise up off your knees onto your toes. Keep your hands directly below your shoulders.
  Contract your abs to keep yourself up and prevent your bottom from sticking up. Remember to keep your belly button pulled in.
• With your head and spine in line, keep your back flat — don't let it curve. Picture your body as a long, straight board.
• Hold this position for 30 seconds.

Sumo Squat to Standing Oblique Crunch

Sumo squats target your quads and inner thighs especially, but Melissa said they also work your glutes, hamstrings, and hip flexors, and the crunches work your obliques and your rectus abdominis, or six-pack muscles [17].

• Stand with your feet shoulder-width apart and feet slightly pointing outward.
• Place your hands behind your head with your elbows out wide.
• Keeping your core tight and weight on your heels, push your butt back as you bend your knees and lower down. Return to standing and bring your right elbow to your left knee, crunching across your body.
• As you open up, lower back down into a squat, then return to standing and crunch the opposite elbow to the opposite knee.
• Continue squatting and alternating crunches for 30 seconds.

Mountain Climbers

Mountain climbers target the abdominals and you'll feel the burn in your triceps and deltoids, too, Melissa told POPSUGAR.

• Start in a high plank — shoulders over your hands and weight on your toes.
• With your core engaged, bring your right knee forward under your chest, with the toes just off the ground. Return to your basic plank. Switch legs, bringing the left knee forward.
• Keep switching legs and pick up the pace until it feels a little like running in place in a plank position.
• Continue for 30 seconds.

Alternating Side Lunge

The alternating side lunge targets the glutes, "specifically the glute medius," Melissa said, as well as the quads, hamstrings, and inner and outer thighs.

• Start with your feet together.
• Keeping your chest lifted, step your right foot wide to the side, coming into a lunge. Your right knee shouldn't go beyond your right toes.
• Push into your right foot to return to standing, then lunge sideways to the left and return to standing.
• Keep alternating for 30 seconds.

Bodyweight Squat to Alternating Kickback

The squat portion of this exercise mainly targets the quads, but it also gets into the hamstrings and glutes. The kickbacks target the glutes, hamstrings, and hip flexors, Melissa noted. You'll also feel your core and calves during this combo, she said.

• Stand upright with your feet shoulder-width apart.
• Sit back into a squat with your weight on your heels and chest up.
• Come back to standing and kick your left leg out behind you, slightly bending at the knee. You should feel this in your glute.
• Return to standing, do another squat, then kick your right leg out behind you.
• Keep doing squats and alternating legs, keeping your core tight, for 30 seconds.