Arnold's Ab Workout: Sculpting The Austrian Oak's Trunk

In 1968, a 20-year-old Arnold Schwarzenegger stepped onstage at the IFBB Mr. Universe and lost to the razor-sharp Frank Zane. In The Encyclopedia of Modern Bodybuilding, Arnold later admitted the defeat was partly due to his lack of abdominal development and overall definition. He vowed to never let conditioning hold him back again.

And he didn’t. Between 1970-1975 and again in 1980, the Austrian Oak dominated the Mr. Olympia stage. Behind the iconic chest and boulder shoulders was a high-volume, brutally consistent ab routine that helped tighten his waist and complete his aesthetic.

Quick Answer

If you want to try Arnold’s ab routine today, keep the spirit but adjust the dose. Run it 2-4 times per week, keep reps high, use controlled tempo, and stop 1-3 reps shy of sloppy form. Pair it with smart nutrition and overall training because visible abs still come down to conditioning.

Key Takeaways

This guide breaks down:

• Arnold’s exact Mr. Olympia-era ab routine
• Exercise-by-exercise instructions
• His personal training tips
• Insights on posing, waist control, and oblique work
• Modern considerations for anyone trying the routine today

Arnold's Ab Workout

Arnold trained abs at the end of his workouts, often multiple times per week and occasionally twice per day leading into competition. His goal wasn’t blocky abs. It was a tight, controlled midsection that visually shrank his waist while making his chest and arms look even bigger.

His 5-exercise routine targeted:

• Upper abs
• Lower abs
• Obliques
• Overall core endurance

Here is his original routine exactly as written:

Arnold’s Ab Routine (1970s)

• Hanging Knee Raises: 3x25-50
• Roman Chair Sit-Ups: 4x25-30
• Lying Leg Raises: 3x25-30
• Side-to-Side Twist: 3x50
• Seated Leg Tucks: 4x25-50

High reps, minimal rest, and controlled tempo were the cornerstones of his approach.

Modern Considerations Before You Try This

• This is a lot of volume. Arnold could handle 500+ reps because he built up to it and lived like a full-time bodybuilder. Most lifters should ramp up slowly.
• Technique matters more than reps. If you are swinging, yanking, or arching hard through your low back, you are training momentum, not abs.
• Visible abs require conditioning. Ab training thickens and strengthens the muscle, but leanness determines how much you see.
• Joint comfort is a green light, not your ego. If a movement irritates your low back or hips, modify it (bent knees, smaller range, slower tempo).

Safety note: If you have a history of low back pain, hip impingement, or hernias, get medical clearance and start with lower volume and easier variations.

The Exercises

1. Hanging Knee Raises

The hanging knee raise, a variation of hanging leg raises, was Arnold’s go-to for hammering the lower portion of the abdominals. Here’s how he did it:

1. Hang from a pull-up bar with your hands shoulder-distance apart. Legs together, knees slightly bent.
2. Initiate by tucking the pelvis slightly (think: ribs down, hips up).
3. Bring your knees toward your midsection, then round slightly at the top as if you are trying to “curl” your pelvis up.
4. Hold the top contracted position for a second.
5. Lower under control to the start position.

Arnold's Training Tip:

Perform the exercise slowly and deliberately to avoid using momentum to get your knees up.

2. Roman Chair Sit-Up

The Roman Chair, or hyperextension bench, is a padded bench with seat and foot supports designed to allow you to train your trunk through a larger range. Here’s how to do the Roman Chair Sit-Up:

1. Sit on the bench with your feet hooked under the foot supports. Fold your arms in front of your body.
2. Maintain a tight core as you lower your torso back to about a 60-70 degree angle. Avoid dropping until your back is parallel to the floor.
3. Contract your abs to curl your torso forward. Squeeze hard in the top position, then repeat.

Arnold's Training Tip:

Place a block under the back of the Roman Chair to increase difficulty. If your gym doesn’t have a dedicated Roman Chair, you can also perform a similar setup on a seated calf raise machine.

3. Lying Leg Raises

The lying leg raise gets debated because it is easy to turn it into a hip flexor-dominant movement. The fix is technique: control your pelvis. Arnold swore by this for lower ab development, and when you keep posterior pelvic tilt and avoid excessive low back arching, it can absolutely light up the midsection.

1. Lie on a flat bench on your back with your butt near the end of the bench so your legs can move freely.
2. Place your hands on the bench by your hips and extend your legs straight (soft knees are fine if your hips feel cranky).
3. Lift your legs as high as possible without losing control of your lower back position.
4. Pause briefly at the top, then lower to just below parallel while keeping tension.

Arnold's Training Tip:

Keep your head up by looking at your feet throughout the movement.

4. Side-to-Side Twist

The side-to-side twist was Arnold’s favorite exercise to develop the obliques. He alternated between seated and standing bent-over versions. Here’s how to do the seated side-to-side twist:

1. Sit on a bench with feet shoulder-width apart and an unloaded barbell across your shoulders. Hold the bar out wide.
2. Keep your head looking forward as you twist as far to the right as you can without bouncing.
3. Hold the end range for a beat, then reverse smoothly to the other side.

Arnold's Training Tip:

Rather than swinging back and forth, perform the exercise in a smooth, fluid motion.

5. Seated Leg Tucks

The seated leg tuck (also called the In and Out Abs Exercise) trains the “ribcage toward pelvis” action that makes abs look tight and controlled.

1. Sit on a bench with your legs together and extended in front of you, knees slightly bent. Hold the sides of the bench for support.
2. Lean back to about a 45-degree angle.
3. Curl your torso as you draw your knees toward your chest.
4. Hold the contraction for a second, then slowly return to the start.

Arnold's Training Tip:

Do not allow your feet to touch the floor between reps.

How To Run Arnold’s Ab Routine Today

Beginner (2x per week)

• Pick 3 movements from the list (one hanging, one flexion-based, one twist or tuck)
• Do 2-3 sets each, 10-20 reps
• Rest 45-75 seconds and keep every rep clean

Intermediate (3x per week)

• Run all 5 exercises but cut sets down slightly
• Example: 2-3 sets per movement, 15-30 reps
• Progress by adding reps first, then adding a set only if recovery stays solid

Advanced (4x per week, Arnold style without the chaos)

• Keep the original exercise list
• Use the original rep targets, but cap sloppy volume
• If your form breaks, the set is done. Period.

3 More Ab Training Tips from the Austrian Oak

1. Training Frequency

Arnold often performed 500+ reps per session and trained abs several times per week, increasing frequency close to competition.

Today, plenty of lifters still do well with higher-frequency ab training as long as recovery is managed and the work stays high-quality.

2. Avoid Heavy Oblique Training (If a Smaller Waist Is the Goal)

Arnold was not genetically narrow-waisted, so he avoided heavy weighted side bends. If you are chasing the classic V-taper look, that logic makes sense.

Important: This is a physique choice, not a universal rule. Athletes and lifters who want a stronger trunk, better carries, and more rotational strength can absolutely train obliques heavy. Just know what you are optimizing for.

3. Work Abs Last

He saved ab work for last so it wouldn’t fatigue his core before heavy lifts.

This is still a smart default for most lifters.

Arnold's Ab Posing Strategy

Arnold’s abs were never his standout feature, but his posing mastery turned them into a strength.

He regularly used:

• Waist-twisting poses to create a smaller-waist illusion
• Quarter-turn transitions that emphasized shoulder width
• Vacuum-style breathing to flatten the midsection
• Torso rotation to accentuate biceps and lats

This is why he could outshine more defined competitors. He understood presentation as deeply as training.

Simple Vacuum Practice (2-3 minutes)

• Exhale fully, then lightly pull the belly button inward and up.
• Hold 10-20 seconds while staying relaxed through the shoulders and neck.
• Repeat for 4-6 rounds.

Wrap Up

Arnold Schwarzenegger's ab routine was a product of its time. From a modern perspective, it is very high volume and includes movements that are easy to do poorly if you rush. However, there is no denying the results he achieved with relentless consistency, controlled reps, and an obsession with waist presentation.

If you are giving this a shot, consider pairing it with more of his classic training templates: Arnold's Chest Workout, Back Workout, Shoulders Workout, and Arms Workout.

Why not give it a try and see how your midsection responds?

(All image credit to original owners)