In and Outs Abs Workout: How To Do, Muscles Worked, Benefits & Alternatives

Get ready to work your core from all sides with the In and Outs Abs Workout. This exercise targets all of the major muscle groups in your core, including the six-pack muscles, transverse abdominis, and obliques.

In just 15-20 minutes, you can make your midsection look better by doing a complete ab workout. No equipment needed – just your own bodyweight.

Ready to ignition your core? Read on to find out more about this workout that burns calories and helps you get strong, defined abs.

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What is In and Outs Workout

The In and Outs Abs Workout is easy to learn and do. You can change it to make it harder or easier.

This intense abs workout alternates between crunch “in” exercises that target the abs and obliques, and “out” exercises that test your transverse abdominals and spinal stability.

The alternating in and out movement patterns recruit the full range of your abs, hitting them from multiple directions for maximized contraction.

In and Outs Workout

In and Outs Muscles Worked

The In and Outs Abs Workout is a compound exercise, meaning that it works multiple muscles at the same time. The main muscles worked during the In and Outs Abs Workout are:

  • Rectus abdominis:  It is responsible for flexing the spine and bringing the ribs closer to the pelvis.
  • Transverse abdominis: The transverse abdominis is a deep core muscle that wraps around the abdomen like a corset. It is responsible for stabilizing the spine and pelvis.
  • Obliques: The obliques are located on the sides of the abdomen.

Beyond the primary muscle groups listed above, the In and Outs Abs Workout also works the following secondary muscles:

  • Hip flexors: They are responsible for bending the hips and bringing the knees towards the chest.
  • Quadriceps: They are responsible for extending the knees.
  • Lower back: The lower back muscles support the spine and help to maintain good posture.
In and Outs Muscles Worked

How to Do In and Outs Exercises

  1. First, find a place that is flat and free of obstacles. Use a mat or soft surface to make the exercise comfortable.
  2. Sit down on the mat, legs extended in front of you.
  3. Place your hands slightly behind you, fingers pointing towards your feet.
  4. Your arms should be straight, and palms should be flat on the ground for support.
  5. Lean back slightly so your torso is at an angle, and lift your feet a few inches off the ground. This forms a kind of ‘V’ shape with your body.
  6. Engage your core muscles. This is crucial for stability and to get the full benefit of the exercise.
  7. Pull your knees toward your chest while simultaneously leaning slightly forward, “closing” the V-shape.
  8. As you “close” the V, your feet will come closer to your body but remain off the ground.
  9. Slowly extend your legs straight out in front of you while leaning back to the starting angled position, “opening” the V-shape again.
  10. Ensure your feet don’t touch the ground to maintain core engagement and intensity.
  11. Continue the motion smoothly, pulling the knees in and then extending them out for the desired number of repetitions.
Know More: 18 Abs Exercises At Home Without Equipment

Tips and Form for Effective In and Outs

Here are some tips for making the In and Outs exercise as safe and beneficial as possible.

1. Prioritize Form Over Speed

Make sure that your movements are controlled and precise. Running through the rounds can compromise your form and put a strain on your lower back.

2. Keep Your Back Straight

It’s essential to maintain a neutral spine throughout the exercise. You should avoid rounding your shoulders or back, as this could lead to discomfort or injury.

3. Engage Your Core

This exercise is all about the core. Make sure you’re not just going through the motions with your legs. Every time you do a set of exercises, tighten and engage your abdominal muscles.

4. Breathe Consistently

Exhale as you bring your knees toward your chest and inhale as you extend your legs out. Proper breathing can enhance muscle function and endurance.

5. Use Your Arms for Support, Not Momentum

While your hands are on the ground for balance, avoid pushing off with them. Let your core do the work. If you’re a pro and want to push yourself, try doing the move without using your hands to help you.

6. Avoid Letting Your Feet Touch the Ground

Aiming to keep your feet off the ground ensures constant tension on the abdominal muscles, increasing the workouts’ effectiveness.

7. Modify If Needed

Listen to your body. If the standard In and Outs movement is initially too challenging, consider a slight modification, such as decreasing the range of motion or placing your hands further behind you for added support.

8. Pair with Complementary Exercises

Include other core-focused movements like planks, Russian twists, or leg raises in your routine to get a comprehensive abdominal workout.

Use our free calculator to know your weight loss calories requirement.

Benefits of the In and Outs Abs Workout

  • Core Strengthening: Targets and tones the rectus abdominis and obliques.
  • Improved Posture: Enhances spinal alignment and reduces back strain.
  • Better Balance: Increases stability in everyday movements and other exercises.
  • Calorie Burn: Engages multiple muscle groups, aiding in fat loss.
  • Enhanced Flexibility: Encourages a wider range of motion in the hips and lower back.
  • Functional Fitness: Supports daily activities that require bending, reaching, or lifting.
  • Compact & Convenient: Requires no equipment and can be done anywhere.


The In and Outs abs workout is a dynamic and effective way to work multiple core muscles and improve posture and balance. As with any exercise, the key is to maintain correct form and consistent practice.

Perform the exercise 2-3 times per week for 10-15 repetitions per set. As you get stronger, you can do more sets and repetitions.

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