A 22cm air-filled pilates ball that adds a new dimension to both mat and reformer work. At that diameter, it sits firmly in the sweet spot for core engagement and stability training — compact enough to position precisely under your lower back, between your knees, or behind your thighs, yet substantial enough to genuinely challenge your balance and activate the deep postural muscles that a flat mat alone cannot reach.The soft, responsive surface works two ways: squeeze it to increase the intensity of inner thigh and abdominal exercises, or rest against it to add gentle support during spinal extensions and side-lying movements. That dual function is what makes the pilates ball one of the most versatile props in a home studio. You can use it to progress movements you have already mastered, or to modify positions while you are still building strength and body awareness.Pilates with a small ball is particularly effective for isolating muscles that larger equipment tends to miss. Placing the ball between your knees during a hundred series deepens adductor activation. Sitting on it during seated exercises introduces subtle instability that asks your stabilisers to respond in real time. These are techniques used in studio settings that translate directly to home practice with nothing more than this single prop.What size pilates ball should you choose? The 22cm diameter in this ball is the standard for classical pilates prop work. It is sized for adults of all heights and works across the full range of pilates exercises, from beginner fundamentals through to advanced sequences. This is the size most pilates instructors recommend for mat and reformer use.Each ball arrives with an inflation straw and plug so you can adjust firmness to suit your preference. A softer inflation gives more surface give and a gentler challenge; firmer inflation increases instability and resistance. Both are valid approaches depending on your session focus and current level.Available in a considered palette: Black, Beige, Blush, Sage, Mocha, Dusty Rose, Sky Blue, Seafoam Green, Butter Yellow, and Espresso. Each shade is chosen to sit naturally in the spaces where you practice, so the ball works as a considered part of your home setup rather than an afterthought. Diameter: 22cm, the standard for pilates prop work Inflation: Includes straw and plug; adjust firmness to suit your practice Construction: Soft, anti-burst material that holds its shape across repeated sessions Use cases: Core activation, inner thigh work, spinal support, balance and stability training, mat pilates, reformer pilates Suitable for: All levels, from first-time practitioners through to regular studio movers Pairs Well WithThe pilates ball works alongside your reformer as a complementary prop, adding instability and targeted muscle activation to exercises that the machine alone does not isolate. It is a natural addition to both the YR Original Reformer and the YR Foldable Reformer setups, rounding out your home studio with a low-footprint tool that genuinely extends what you can do on and off the carriage.CareWipe down with a damp cloth after each session. Keep the ball out of direct sunlight to protect the colour over time.