Backstroke: A Complete Guide

Quick Intro

Backstroke is a reformer Pilates exercise performed lying supine on the carriage, straps in hand, knees bent to the chest with the arms reaching toward the feet inside the knees. Extending both arms overhead and both legs forward at the same moment, then circling the arms wide out to the sides before returning, this mimics a swimming backstroke motion against spring resistance across four sequenced phases.

Equipment Needed

A Pilates Reformer is required, since the straps and the supine spring resistance are the mechanism this four-phase sequence works against. No other prop plays any part in it.

Why It Matters

Chaining four phases of arm and leg movement together in one continuous pattern takes timing, and sustaining that pattern through a working set demands staying power and range through the shoulders and hips. A large back muscle (latissimus dorsi) helps drive the arm circle back to the start, and the deep core muscle that wraps around the torso like a corset (transverse abdominis) braces the trunk to keep the lower back from arching off the carriage. A muscle along the side of the ribcage (serratus anterior) supports the shoulder blade through the overhead reach, and the front of the shoulder cap (deltoid, anterior) assists the initial arm extension. The deep hip flexor (hip flexors, iliopsoas) holds the extended legs off the carriage, and the abdominal muscles running down the front of the stomach (rectus abdominis) keep the trunk stable as the limbs move through all four phases.

When to Do It

Backstroke works well cycled into the reformer’s supine arm series, usually alongside the other swimming-inspired patterns performed lying down. Two to three sessions a week is a reasonable pace for building this four-phase sequence.

Anyone with a current shoulder or low-back issue should get individual guidance before adding this exercise, since the arms and legs both move through a full range under spring tension across every phase.

Getting Ready

A few slow rounds of just the arm-and-leg extension, without the circle yet, preview the first phase before the full four-part sequence is attempted. Bringing the knees to the chest and reaching the arms toward the feet for a breath or two checks the starting shape this exercise depends on.

Step-by-Step Instructions

1. The start. Lie supine, straps in hand, knees bent to the chest, arms reaching toward the feet inside the knees.

2. The extend. Extend both arms overhead and both legs forward at the same moment.

3. The circle. Circle the arms wide out to the sides while the legs stay extended.

4. The return. Sweep the arms back to the start as the knees bend back in to the chest, completing the pattern.

How Many, How Often

Backstroke is dosed by full sequences, with each start-extend-circle-and-return counting as one.

The arms and legs finishing each phase together matters more here than how quickly the sequence moves, since limbs that fall out of sync are the clearest sign the coordination this exercise trains hasn’t been fully learned yet.

Modifications and Variations

As an easier version, Backstroke — Legs at 90 keeps the legs at a 90-degree angle instead of extending them fully forward, reducing the hip-flexor demand while the arm-and-breath pattern is learned.

As a harder version, Backstroke — Slow Arc performs the same four-phase sequence at a deliberately slower pace, removing momentum from the arm circle and asking the shoulders to control the wider arc for longer.

Common Mistakes to Avoid

Letting the lower back arch off the carriage. Allowing the spine to lift as the legs extend forward trades the deep core bracing this exercise depends on for a passive stretch through the low back. Keeping the lower back pressed down throughout the extension protects the spine.

Letting the arms and legs finish out of sync. Extending the legs well before or after the arms reach overhead breaks the timing this exercise is built to train. Practicing the extension slowly until both limbs finish together is worth more than rushing a mismatched sequence.

Holding the breath through the circle phase. Bracing without breathing as the arms sweep wide adds unnecessary tension to a pattern that depends on continuous breath. Coordinating an exhale with the arm circle keeps the whole sequence flowing.

After Your Set

Hugging both knees into the chest for a few breaths releases the lower back after the repeated extensions. A gentle shoulder roll on each side eases out the upper back that drove the arm circles.

Going Deeper

This exercise is a coordination test within the supine arm work, since chaining four distinct phases into one continuous pattern asks for more timing than single-phase exercises do. A common sticking point shows up under fatigue: as the set continues, the arms and legs tend to drift out of sync, with one finishing a beat ahead of the other. Slowing the whole sequence down until every phase lands together again, even at the cost of fewer sequences per set, rebuilds coordination faster than pushing through a set where the limbs have stopped matching.

Someone new to this exercise generally manages the full four-phase sequence at a slow pace within the first few sessions, then works toward a smoother, faster flow over two to three weeks.

How to Know You’re Improving

1. Arms and legs that extend and return together on every sequence
2. A lower back that stays pressed down through the full extension
3. A breath that stays coordinated with the arm circle, never held
4. A sequence pace that quickens while the timing stays matched

Limbs that stay in time matter more than how fast the sequence moves.

Muscles Worked

• Latissimus Dorsi (a large back muscle, helping drive the arm circle back to the start)
• Transverse Abdominis (a deep core muscle that wraps around the torso like a corset, bracing the trunk to keep the lower back from arching off the carriage)
• Serratus Anterior (a muscle along the side of the ribcage, supporting the shoulder blade through the overhead reach)
• Anterior Deltoid (the front of the shoulder cap, assisting the initial arm extension)
• Iliopsoas (the deep hip flexor, holding the extended legs off the carriage)
• Rectus Abdominis (the abdominal muscles running down the front of the stomach, keeping the trunk stable as the limbs move through all four phases)

FAQ

Why does this exercise have four separate phases instead of one simple movement? The four phases, the bent start, the simultaneous extension, the wide circle and the return, chain together an arm-and-leg coordination pattern modeled on a swimming stroke, each phase asking for a slightly different kind of control.

Is this exercise mainly for the core or the shoulders? Both are trained here, with the deep core bracing throughout to protect the low back while the shoulders and upper back drive the wide arm circle against spring resistance.

Is some low back or shoulder fatigue after this exercise normal? Yes, a worked feeling through the low back muscles that braced and the shoulders that circled is expected after a full working set. A sharp pain that stays fixed at one point in the low back is a separate matter, worth pausing for and mentioning to a doctor or physical therapist if it doesn’t settle.

Is keeping the knees bent acceptable if extending the legs fully feels like too much? Yes, keeping the legs at a 90-degree angle is a reasonable way to build the arm-and-breath pattern before adding the fuller leg extension, and Backstroke — Legs at 90 is built that way.

How often should Backstroke be practiced? Two to three times a week, cycled into the supine arm series in a broader reformer routine, suits most people building this four-phase sequence.

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Related to Backstroke — Legs at 90 as the easier version performed with the legs bent to 90 degrees and Backstroke — Slow Arc as the harder version performed at a deliberately slower pace.