What Is a Pilates Ball? Your Complete Guide to the 20cm Mini Exercise Ball

Small, squishy, and deceptively simple — the 20cm pilates ball is one of the most underrated props in any wellness practice. Whether you're doing pilates, yoga, rehabilitation exercises, or just looking for a way to make your core workout significantly harder without lifting a single weight, the mini exercise ball belongs in your kit.

What Makes the 20cm Size Special?

Pilates balls come in different sizes — from 9cm up to 30cm — but the 20cm is widely considered the most versatile. Here's why:

At 20cm, the ball is the perfect size to squeeze between your knees in exercises like bridges and hundreds, tuck under your lower back for supported core work, or hold between your ankles during leg circles and scissors.

The Benefits of Using a Pilates Ball

1. Deep Inner Thigh Activation

Squeezing the ball between your knees or thighs instantly activates your adductors — the inner thigh muscles that are notoriously hard to target without equipment. This engagement also stabilizes the pelvis and takes pressure off the lower back during core exercises.

2. Spinal Decompression & Lower Back Relief

Placed under your lumbar spine (lower back) during supine exercises, the ball provides a gentle, supportive curve that decompresses the spine and opens the chest. For anyone who sits at a desk — even a desk with a beautiful Bali villa view — this is deeply relieving.

3. Core Stability Without Crunches

The ball's slight instability forces your deep stabilising muscles — transverse abdominis, multifidus, pelvic floor — to engage constantly to maintain position. This is exactly what pilates is about: working the muscles you can't see, not just the ones that show in a mirror.

4. Improved Proprioception & Balance

Proprioception is your body's sense of where it is in space. Exercising on an unstable surface (even a small one) trains your nervous system and dramatically improves balance over time — directly benefiting every standing yoga pose you practice.

5. Prenatal-Friendly

The 20cm pilates ball is one of the most recommended props for prenatal exercise — gentle enough for pregnancy, effective for maintaining core strength and pelvic floor function. Always consult your doctor first.

6. Portable & Lightweight

Deflated, it fits in your yoga bag. Inflated, it's ready in seconds with a small pump or even by mouth. For Bali's active lifestyle — where you might practice at home, in a studio, or on the beach — portability matters.

How to Inflate Your 20cm Pilates Ball

The inflation level matters more than most people realize:

• Soft inflation (recommended for beginners): Ball gives slightly when squeezed — gentler on joints, easier to control
• Medium inflation (standard): Ball has some give but holds its shape — the most versatile inflation level for general use
• Firm inflation: Ball is quite hard — more resistance and instability, better for advanced users

12 Best 20cm Pilates Ball Exercises

All you need is a mat, your ball, and about 20 minutes:

For Core

1. Ball Between Knees Bridge
Lie on your back, ball between your knees, feet flat. Squeeze the ball and lift your hips to the ceiling. The squeeze activates inner thighs and glutes simultaneously. Hold 3 seconds at the top.

2. Supine Ball Squeeze
Lying on your back, ball between your knees, arms by your sides. Simply pulse the ball — squeeze and release — 20 times. Deceptively hard.

3. Hundreds Prep with Ball
Ball between your ankles, legs at tabletop (90°), arms extended long by your sides and pulsing. The ball keeps the legs engaged and prevents them from separating.

4. Dead Bug with Ball
Ball between knees at tabletop, arms reaching to ceiling. Lower opposite arm and leg while keeping the ball still. Incredible deep core challenge.

5. Seated Ball Squeeze
Sit tall, ball between your knees. Squeeze and hold for 5 seconds, release. Repeat. Combines inner thigh, pelvic floor, and postural muscles in one movement.

For Glutes & Legs

6. Pilates Ball Squat Against Wall
Ball between your back and the wall, feet hip-width, walk feet out slightly. Slide down into a squat, hold 5–10 seconds, slide back up. The ball rolls smoothly and takes pressure off your knees.

7. Inner Thigh Press Circles
Lying on your back, ball between your inner thighs, legs extended to the ceiling. Draw small circles with your legs while squeezing the ball. Targets inner thighs and low abs.

8. Standing Inner Thigh Squeeze
Standing, ball between your knees. Squeeze and hold while doing small rises onto your toes. Ballet-inspired, surprisingly difficult.

For Back & Posture

9. Supported Back Extension
Ball under your lower back/lumbar spine, arms crossed over chest. Gently arch back over the ball, feeling a gentle opening in the thoracic spine. Hold 30–60 seconds.

10. Chest Opener
Ball between your shoulder blades (upper back), arms open wide to the sides. Gently let gravity open your chest over the ball. One of the best posture exercises available — especially important if you work on a laptop.

For Flexibility & Yoga Complement

11. Supported Child's Pose
Ball between your chest and thighs in child's pose, arms forward. The ball supports the torso and allows a deeper, longer hold. Perfect for yin practice.

12. Supine Spinal Twist Support
Ball between your knees in supine spinal twist, letting the legs drop to one side while the ball keeps the knees stacked. Deeper hip opening with spinal support.

Pilates Ball vs Other Props — Do You Need Both?

The pilates ball and booty band are actually a perfect pairing — the band targets outer glutes and hips, while the ball targets inner thighs and deep core. Together they give you complete lower body and core coverage in one compact, affordable kit.

Who Is the Pilates Ball For?

• Pilates practitioners — essential prop for home practice
• Yogis — adds a new dimension to core and hip work
• Prenatal practitioners — gentle and effective for pregnancy-safe exercise
• Office workers & digital nomads in Bali — corrects posture, relieves lower back tension from sitting
• Beginners — accessible entry point into core training without intimidating equipment
• Anyone with lower back pain — the supported back exercises are gentle and therapeutic

How to Care for Your Pilates Ball

• Wipe clean with a damp cloth after each use — especially important in Bali's humidity
• Keep out of direct sunlight when not in use — UV degrades the rubber over time
• Don't overinflate — the ball should never feel hard as a rock
• Store at room temperature — extreme heat (like a car left in the Bali sun) can cause the ball to expand and potentially split
• Check for slow leaks periodically — if it feels softer than usual, add a little air

Frequently Asked Questions

What's the difference between a pilates ball and a stability ball?

A stability ball (Swiss ball) is large — 55–75cm — designed to sit or lie on. A pilates ball (20cm) is placed between body parts to add resistance and instability to specific exercises. They're used very differently and complement each other rather than replacing each other.

Can I use a pilates ball if I have lower back pain?

Many physiotherapists actually recommend the mini ball for lower back rehabilitation — particularly the supported back extension and chest opener exercises. However, always consult your doctor or physio before starting if you have an existing condition.

How often should I use a pilates ball?

Daily use is perfectly fine — it's low-impact. Even 10–15 minutes of ball exercises before your yoga or pilates class will noticeably improve your practice within a few weeks.

Can children use a pilates ball?

Yes — the 20cm ball is safe and fun for children to use under adult supervision. Many paediatric physiotherapists use mini balls for core and coordination exercises with kids.

Where can I buy a pilates ball in Bali?

At Yoga Republik in Canggu — we carry 20cm pilates balls alongside yoga mats, booty bands, props, and all the activewear and accessories you need for your practice in Bali.