Coordination: A Complete Guide
Quick Intro
Coordination is a reformer Pilates exercise performed lying supine, straps in both hands, knees bent to the chest. Curling up, the arms extend to pull the straps down to the hips while the legs extend to 45 degrees and open and close twice, then the whole sequence reverses, hugging the knees back in as the straps release, a four-phase pattern requiring precise timing between the arms and legs under spring resistance.
Equipment Needed
A Pilates Reformer is required, since the strap resistance on the arms is the mechanism this timed sequence works against. The straps stay in the hands from start to finish.
Why It Matters
Timing four separate phases between the upper and lower body under spring tension is a test of coordination, sustaining the curled-up position through the whole sequence takes staying power and reaching the legs to their extended, opened position asks for a working range through the hips. The deep core muscle that wraps around the torso like a corset (transverse abdominis) and the long muscle running down the front of the abdomen (rectus abdominis) hold the curled-up position through all four phases, and the muscle group at the front of the hip (hip flexors, iliopsoas) lifts and controls the extended legs. The inner thigh muscles (adductors) drive the legs back together after opening, a large back muscle (latissimus dorsi) pulls the straps down to the hips and a muscle along the side of the ribcage (serratus anterior) helps stabilize the shoulder blades as the arms extend.
When to Do It
Coordination works well once a curled-up abdominal position and a controlled leg extension both feel steady on their own, combined here into a single timed sequence. Two to three sessions a week is a reasonable pace for building this four-phase pattern.
Anyone with a current neck or low-back issue should get individual guidance before adding this exercise, since the curled-up position is sustained through the arm pull and the leg opening and closing.
Getting Ready
Curling up with the knees bent to the chest and holding the position for a few breaths, without the straps moving yet, checks the abdominal hold this exercise depends on. A slow single phase, extending the legs and arms together without the leg opening, previews the full timing before the complete sequence is attempted.
Step-by-Step Instructions
1. The setup. Lie supine, straps in both hands, knees bent to the chest, curling the head and shoulders up off the carriage.
2. The extension. Extend the arms to pull the straps down to the hips while simultaneously extending the legs out to 45 degrees.
3. The opening. Open and close the legs twice while the arms and the curled-up position both stay steady.
4. The reverse. Hug the knees back in toward the chest as the straps release, returning to the starting position with control.
How Many, How Often
Coordination is dosed by reps, with each full four-phase sequence counting as one.
| Level | Where you’re at | What to do |
|---|---|---|
| Beginner | New to timing the arms and legs together | 2 sets of 3 to 4 reps |
| Intermediate | The four phases complete in sequence without rushing | 2 to 3 sets of 4 to 6 reps |
| Advanced | Comfortable with the full timing under working resistance | 3 sets of 6 to 8 reps |
The arms and legs finishing each phase together matters more here than how many reps get completed or how fast, since a sequence that blurs together trades away the timing this exercise trains.
Modifications and Variations
As an easier version, Coordination — No Leg Opening extends the legs and arms together without the leg-opening phase, simplifying the timing task while the core curl and strap pull are learned.
As a harder version, Coordination — Three Opens adds a third leg opening at full extension, extending the time the abdominals must hold the position.
Common Mistakes to Avoid
Letting the curled-up position sag partway through the sequence. Allowing the head and shoulders to drop back down before all four phases finish breaks the sustained hold this exercise is built around. Keeping the curl steady from the first phase to the last is what makes the sequence count.
Rushing the phases. Moving through the extension, opening and reverse faster than the timing calls for turns a precise sequence into a blur. Slowing down until each phase finishes before the next begins keeps the timing clear.
Letting the legs open wider than the arms can match. Opening the legs beyond what the upper body’s own timing can track turns a synchronized movement into two separate ones. Keeping the leg opening modest enough to finish with the arms is what the sequence depends on.
After Your Set
Hugging both knees to the chest for a few breaths releases the low back after the sustained curl. A few slow shoulder rolls ease out the upper back and arms that pulled the straps through the sequence.
Going Deeper
Combining all four phases into one timed sequence asks the upper and lower body to work together in a way the separate pieces do not. The curl tends to sag as the legs open, the point where the sequence asks the most of the abdominals. Slowing the whole sequence down for now, with the curl staying steady, builds the timing faster than hurrying through with a sagging curl.
Someone new to this exercise generally manages a slow, deliberate sequence within the first few sessions, then works toward a smoother, quicker timing over the following couple of weeks.
How to Know You’re Improving
- A curled-up position that stays steady through all four phases
- Arms and legs that finish extending at the same moment
- A leg opening that stays controlled and modest
- A sequence that flows smoothly from start to reverse without pausing
A steady curl and matched timing matter more than how many reps get completed.
Muscles Worked
- Transverse Abdominis (a deep core muscle that wraps around the torso like a corset, holding the curled-up position through all four phases)
- Rectus Abdominis (the long muscle running down the front of the abdomen, holding the curled-up position through all four phases)
- Iliopsoas (the muscle group at the front of the hip, lifting and controlling the extended legs)
- Adductors (the inner thigh muscles, driving the legs back together after opening)
- Latissimus Dorsi (a large back muscle, pulling the straps down to the hips)
- Serratus Anterior (a muscle along the side of the ribcage, helping stabilize the shoulder blades as the arms extend)
FAQ
Why does this exercise combine so many movements at once? Pairing the arm pull with the leg extension and opening in one timed sequence trains the upper and lower body to work together under spring resistance, a demand no single-phase exercise reaches on its own.
Are strong abdominals needed before attempting the full sequence? A curled-up position that holds steady on its own for a few breaths comes first, since all four phases of this sequence depend on that hold not breaking down.
Is some abdominal or hip-flexor fatigue after this exercise normal? Yes, a worked feeling through the abdominals and the front of the hips after a full set is expected. A sharp pain in the neck or low back is a separate signal, worth pausing for and mentioning to a doctor or physical therapist if it persists.
Is leaving out the leg opening acceptable if the full sequence feels like too much? Yes, extending the legs and arms together without the leg-opening phase is a reasonable way to build the timing first, and Coordination — No Leg Opening is built that way.
How often should Coordination be practiced? Two to three times a week, once the curled-up hold and leg extension each feel steady on their own, suits most people building toward this four-phase sequence.
Related to Coordination — No Leg Opening as the easier version performed without the leg-opening phase and Coordination — Three Opens as the harder version with an extra leg opening added.