The Hundred: A Complete Guide
Quick Intro
The Hundred is a mat Pilates exercise performed lying on the back with the legs extended at a 45-degree angle, pumping the arms up and down in small, fast beats while holding a curled-up upper body position for 100 total counts. It opens the classical Pilates mat order and sets the working tone, a deep core hold (the “powerhouse” in Pilates terminology) sustained continuously while a five-count inhale and five-count exhale pace the arm pump.
Equipment Needed
No equipment is required. A Yoga Mat under the spine and hips is optional, mainly for comfort on a hard floor.
Why It Matters
Holding one curled position while the arms pump for a full 100 counts builds endurance in the abdominals and takes coordination to keep the breath and the beats matched. It also raises the heart rate, which most exercises in the classical mat order do not. A deep core muscle that wraps around the torso like a corset (transverse abdominis) and the abdominal muscles running down the front of the stomach (rectus abdominis) hold the curled spine steady for the full set. The deep hip flexor (hip flexors, iliopsoas) keeps the extended legs from dropping, and a muscle along the side of the ribcage (serratus anterior) and the front of the shoulder cap (deltoid, anterior) drive the small, fast arm pump.
When to Do It
The Hundred works well as the opening exercise of a Pilates mat session, as it sits at the start of the classical repertoire, warming the powerhouse and setting the breath pattern for everything that follows. Most people get good results training it two to four times a week as part of a broader mat routine.
Anyone with a current neck, lower back or shoulder issue should get individual guidance before adding this exercise, since holding a curled position for 100 counts places sustained demand on all three.
Getting Ready
A few rounds of Pilates Breathing, drawing the ribs in on the exhale, prime the breath pattern this exercise depends on. Lying down and curling up for just ten or so pumps previews how the neck and lower back feel that day before committing to a full 100 count.
Step-by-Step Instructions
1. The setup. Lie on the back with the legs extended and raised to a 45-degree angle, arms resting by the sides.
2. The curl. Curl the head, neck and shoulders up off the mat, reaching the arms forward just above hip height.
3. The pump. Pump the arms up and down in small, fast beats from the shoulder, five beats on the inhale and five on the exhale.
4. The count. Continue the breath-paced pump to 100 total beats, then lower the head and legs to rest.
How Many, How Often
The Hundred is dosed by breath cycles, with the classical target being ten full cycles of five inhale-pumps and five exhale-pumps, 100 pumps total.
| Level | Where you’re at | What to do |
|---|---|---|
| Beginner | New to holding the curled position | 3 to 5 breath cycles (30 to 50 pumps), with the legs in tabletop or the head resting down if the neck fatigues |
| Intermediate | The curl and breath pattern feel steady | 6 to 8 breath cycles, building toward the full 100 |
| Advanced | Comfortable holding the full curl for 100 counts | The full 10 cycles, or move to Hundred — Legs at 30 Degrees for a lower leg angle and a greater hip flexor demand |
Keeping the lower back pressed flat into the mat matters more here than finishing all 100 pumps, since a lower back that arches off the floor is the clearest sign the hip flexors have taken over from the deep abdominals this exercise is built to train.
Modifications and Variations
As an easier version, Hundred — Legs in Tabletop bends the knees to a tabletop position, taking weight off the lower back and hip flexors while the breath pattern and arm pump are learned.
As a harder version, Hundred — Legs at 30 Degrees lowers the legs to a shallower 30-degree angle, adding load to the hip flexors and making it harder to keep the lower back flat against the mat.
Common Mistakes to Avoid
Letting the lower back arch off the mat. Allowing the lower back to lift away from the floor as the legs and pump continue shifts the load from the deep abdominals onto the hip flexors and spine. Pressing the lower back flat, even if that means raising the legs higher or bending the knees, keeps the target muscles working.
Straining the neck to hold the curl. Pulling on the neck or letting the chin jut forward to keep the head up fatigues the neck long before the powerhouse does. Keeping a small, consistent gap between the chin and the chest and lowering the head slightly if it strains protects the neck through the full count.
Pumping from the elbow. Bending the elbows to generate the arm pump turns a small, controlled shoulder movement into a looser, less precise one. Keeping the arms straight and the pump small and fast from the shoulder is what the classical version trains.
After Your Set
Drawing both knees to the chest and rocking gently side to side releases the lower back after a set built around a sustained curled hold. A few slow neck rolls, side to side, ease any tension the head-lifted position left in the neck.
Going Deeper
The Hundred usually sits as the opening exercise of a full mat session, priming the powerhouse and the breath pattern that carries through everything that follows in the classical order. The lower back is the first thing to tire, and it’s tempting to let it arch off the mat to keep the pump count moving toward 100. Raising the legs or bending the knees to keep the lower back flat builds the abdominal strength the exercise is for faster than forcing the full count with an arched spine.
Someone new to this exercise generally learns a stable curl and breath pattern within the first few sessions, and works up to the full 100-count set somewhere in the two to four week range as the deep core and hip flexors adapt together.
How to Know You’re Improving
- A lower back that stays pressed flat into the mat for the full set
- A neck that stays relaxed, with the chin held a small distance from the chest
- An arm pump that stays small, fast and driven from the shoulder, not the elbow
- A full 100-count set completed with the legs at 45 degrees or lower, without the lower back lifting
A lower back that never leaves the mat shows progress more reliably than the number of pumps completed.
Muscles Worked
- Transverse Abdominis (a deep core muscle that wraps around the torso like a corset, holding the deep brace for all one hundred counts)
- Rectus Abdominis (the abdominal muscles running down the front of the stomach, keeping the head and shoulders curled up off the mat)
- Iliopsoas (the hip flexor group at the front of the hip, holding the extended legs at their low angle without letting them drop)
- Serratus Anterior (a muscle along the side of the ribcage, anchoring the shoulder blades flat as the arms beat)
- Anterior Deltoid (the front of the shoulder cap, driving the fast arm pump from the shoulder)
FAQ
Why does The Hundred come first in a Pilates mat session? It’s the classical opening exercise of the mat repertoire, built to warm the deep core (the “powerhouse”) and establish the five-count inhale, five-count exhale breath pattern used throughout the rest of the session.
Why does this exercise feel more like a cardio exercise than other Pilates moves? Sustaining a curled position through 100 continuous arm pumps raises the heart rate in a way that most other mat exercises, built around fewer, slower reps, don’t.
Is some neck or ab fatigue after this exercise normal? Yes, a burning fatigue through the abdominals and some neck tiredness by the end of a full 100 count is expected. Sharp pain in the neck or lower back is different and worth easing off for, with a doctor or physical therapist a good next call if it persists.
How does the 30-degree version differ? Hundred — Legs at 30 Degrees lowers the legs to a shallower angle, which adds load to the hip flexors and makes keeping the lower back flat against the mat considerably harder than the standard 45-degree version.
How often should The Hundred be practiced? Two to four sessions a week, as the opener of a broader Pilates mat routine, suits most people well.
Related to Hundred — Legs in Tabletop as the easier version with the knees bent and Hundred — Legs at 30 Degrees as the harder version with a lower leg angle.