The Ultimate 10-Minute HIIT Workout for Your Abs

Grinding out set after set of crunches and sit-ups can get really boring_._ But if you want killer abs you have to do crunches, right? Wrong! There are countless ways to work your core that have nothing to do with the old-school sit-ups you did in elementary school gym class.

Cole Fritz, a certified personal trainer at Life Time in Parker, Colorado, has the scoop on the benefits of high-intensity interval training (aka HIIT) for your abs and created a quick, 10-minute HIIT workout that tightens, strengthens and tones every part of your mid-section — without doing a single crunch.

Read more: 7 Benefits of HIIT Even Beginners Can Tap Into

If you want to maximize your time and exercise intensity, HIIT might be exactly what you need. "HIIT training for abs can be a huge benefit to anyone," says Fritz. "Core stability is great for our daily activities, but if we're always using the same exercise medium such as isometric holds, we're missing out on other areas of performance for abs."

Plus, the abdominal muscles are capable of doing work other than isometrics, which is why Fritz likes HIIT — not to mention the added benefit of a super-intense workout!

• Think: "belly button into spine" (like someone is going hit you in the stomach). This helps keep your core tight and makes the exercises harder and more effective.
  
• Keep your back flat, hips tucked underneath and squeeze your glutes. This lets you zero in on core engagement and allows for safer and better execution of the exercises.
  
• Draw your shoulder blades down and back (think: into your back pocket) with your head back and chin tucked.

This HIIT session is divided into two segments: The first part incorporates isometric holds, explosive work and functional stability. The second segment consists of a cooldown that focuses on your lower core, while also stretching the hamstrings.

Do: Three to five minutes of easy cardio drills (jumping jack, jump rope, high knees, jogging in place, etc.) and dynamic stretches.

Do: Each exercise for 30 seconds, resting 30 seconds before moving to the next move. Do the entire circuit three times.

• Bear plank
  
• Half-kneeling halos (15 seconds in each direction)
  
• Cross-body mountain climbers
  
• Medicine ball slams

Move 1: Bear Plank

1. Start on a mat on all fours, toes tucked underneath your feet.
2. Lift your knees off the floor about one to two inches.
3. Engage your core by drawing your belly button to your spine. Keep your back flat, hips tucked underneath and squeeze your glutes.
4. Hold this position with your glutes more toward your ankles, then leaning forward over the into the shoulders.

Move 2: Half-Kneeling Halos

1. Transition straight from the bear planks into a half-kneeling position (like a lunge but with one knee on the floor).
2. In the half-kneeling position, the leg that is up is in line with the body and making a 90-degree angle (if looking at yourself from the side). The back leg is also creating a 90-degree angle.
3. Holding a five- or 10-pound plate centered at your chest, rotate the plate around your head for 15 seconds.
4. Switch legs and rotate the plate in the other direction for another 15 seconds.
5. Focus on your coordination with the plate as you transition between positions, trying not to fall over sideways.

Move 3: Cross-Body Mountain Climbers

1. Start in a high plank position: long body, toes underneath you, core strong, flat back and glutes tight.
2. Wrists, elbows and shoulders should line up you as you push your body away from the ground. Remember to keep the triceps flexed during this exercise to keep pressure off your elbows.
3. Bring one knee to the opposite elbow.
4. Return the knee back.
5. Repeat on the other side and continue alternating.

Move 4: Medicine Ball Slams

1. Stand with your feet shoulder-width apart and knees bent, weight in the heels.
2. Grab a medicine ball and bring it over your head.
3. Slam the ball into the ground with as much force as possible, so that it bounces up high enough to catch.
4. Remember to breathe out when slamming the ball down and draw the belly button in hard.

Do: Both exercises for 30 seconds each with no rest in between. Rest for 30 seconds, then repeat the super-set.

• Lying side touches
  
• Lying leg raise

Move 1: Lying Side Touches

1. Lie on the mat, with knees bent and heels close to the glutes. Lift your shoulders and upper back slightly off the ground but keep your neck neutral.
2. Bend to one side and reach down as if trying to touch your heel. Only go as far as you can while keeping the head back and down so that you're looking at the ceiling.
3. Return to the starting position and repeat on the other side.
4. Keep alternating sides.

Move 2: Lying Leg Raises

1. Lie flat on the mat, with your legs extended out straight.
2. Place your hands under your lower back/butt.
3. Bring your legs as high as you can off the floor until they're above the hips, perpendicular to the floor.
4. Slowly lower your legs without touching the ground and repeat.
5. If the lower back comes off the ground, go back up to where it stays touching — that's your range of motion for this exercise.

Read more: Why You Should Add Body-Weight HIIT Workouts to Your Routine

Do: Three to five minutes of waking and static stretches, holding each one for 20 to 30 seconds.