What the core really is, and why it matters more as you age
Say "core" in a gym and most people picture a six-pack. That picture has sold a great many crunch machines, and it gets the job of the trunk almost entirely wrong. The muscles you can see in a mirror are only the outer layer of a system that wraps all the way round your middle, from the breathing muscle under your ribs to the floor of your pelvis.
At 25 this hardly matters, because you have strength to spare and can get away with poor control. At 65 it matters a great deal. Getting out of a low armchair, lifting a suitcase into the boot or catching yourself on an icy kerb all depend on a trunk that can stiffen at the right moment and stay supple the rest of the time. US physical therapist and Pilates teacher Tina Sferra is one of several writers who treat core strength as a question of longevity rather than appearance, and I think that is the right way round.
What the core actually is
The most useful picture is a canister. The diaphragm forms the lid, the pelvic floor forms the base, and the walls are the deep abdominal muscles at the front and sides and the small spinal muscles at the back. Working together, they manage pressure inside the trunk, which helps steady the spine when you lift, cough or brace for a fall. Around that canister sit the bigger muscles that bend, twist and extend the trunk. Below it are the hip muscles that connect your middle to your legs.
| Part | What it does | Pilates work that trains it |
|---|---|---|
| Diaphragm | Main breathing muscle, the lid of the canister | Lateral breathing, The Hundred |
| Pelvic floor | The base; supports the pelvic organs and continence | A gentle lift on the exhale in bridging and footwork |
| Transversus abdominis | Deepest abdominal layer, wraps the waist like a wide belt | Single Leg Stretch, any work where the belly draws in without gripping |
| Obliques | Rotate and side bend the trunk, and resist being twisted | Saw, Spine Twist, Criss Cross, Side Bend |
| Rectus abdominis | Curls the trunk forward; the visible six-pack | Roll Up, The Hundred |
| Multifidus and erector spinae | Extend the spine and steady each segment | Swan, Swimming, Double Leg Kick |
| Glutes and deep hip muscles | Link the pelvis to the legs, hold you steady on one leg | Shoulder Bridge, Side Kick series |
Classical teachers call this whole band, roughly from the lower ribs to the tops of the thighs, the powerhouse. The word is old fashioned and a little theatrical. It is still more accurate than "abs", because it includes the back, the hips and the seat.
Why it matters more with age
Adults lose muscle mass and strength gradually from midlife, and the loss tends to speed up in the later decades. Strength usually falls faster than size, and power (the ability to produce force quickly) falls fastest of all. That last point is the one people miss. Recovering from a trip is not a slow, heavy lift. It is a fast reaction in which the trunk has to stiffen and the hips have to swing a leg into place in a fraction of a second.
A capable trunk also changes the ordinary parts of a day. Getting up from the floor after playing with grandchildren, turning to reverse the car, carrying shopping upstairs, pulling on socks while standing: each one asks the middle of the body to hold steady while the arms or legs do something else. When that control fades, people compensate by holding their breath, bracing everything at once or quietly avoiding the movement. Avoidance is the expensive option. What you stop doing, you slowly lose.
Muscle also needs raw material. If you are training to keep your strength, eating enough protein across the day belongs to the same project as the exercise.
How Pilates trains it
Breath first
Most Pilates schools begin with breathing wide into the back and sides of the ribs, which keeps the abdominal wall gently active while air moves in and out. It sounds trivial. In practice it teaches you to keep some tone through your middle without locking your ribs and holding your breath, and that is precisely the skill an older body needs when it lifts something heavy.
Stillness while something else moves
Much of the mat repertoire asks the pelvis and spine to stay quiet while the limbs move. In Single Leg Stretch the legs change places while the trunk stays curled and still. In the Side Kick series the top leg swings forward and back while the waist refuses to be dragged along. On the reformer, Footwork does the same job lying down: the carriage travels, the pelvis does not rock. Control like this carries over well to walking, stairs and carrying.
Every direction, not only forward
A crunch trains one thing, which is curling forward. A well-taught Pilates session also extends the spine (Swan, Swimming), bends it sideways (Side Bend) and rotates it (Saw, Spine Twist). The back extensors deserve particular attention later in life, because posture tends to drift forward with age and those muscles help hold you upright. The classical system that Romana Kryzanowska kept teaching for decades has always balanced its curling exercises with extension, and that balance is one of its quiet strengths.
What the evidence generally says
Claims about the core run well ahead of the research, so a little care is needed here. Trials of Pilates in older adults have generally reported improvements in balance and in some measures of strength and mobility, though many of the studies are small and short. Trials of Pilates for chronic low back pain have generally found modest improvements in pain and function. Reviews comparing specific "core stability" training with general exercise for back pain tend to find similar benefits from both. The exact muscle you are thinking about seems to matter less than moving regularly and building up gradually.
I find that reassuring. You do not need to switch on one deep abdominal muscle by force of concentration. You need a trunk that works with the rest of you, trained in several directions and at enough effort to count, and made harder over time. The way good teachers handle progression from basic to intermediate work applies here as much as in any studio.
One caution. With osteoporosis you are usually advised to limit repeated, loaded forward bending such as Roll Ups, so get advice before you start. The same goes for pelvic floor symptoms, back pain that travels into the leg, pregnancy or the months after giving birth: see a physiotherapist or an experienced teacher in person before choosing exercises.
A short checklist for the week
You do not need an hour a day. Three short sessions a week, each touching every direction, will do more than a daily set of crunches:
- Two minutes of lateral breathing, lying on your back with knees bent.
- The Hundred, knees bent if needed, building towards 100 counts.
- Single Leg Stretch, 6 to 8 per side, trunk steady.
- Shoulder Bridge or a simple glute bridge, 8 slow repetitions.
- Swimming or a small Swan, 6 to 8 repetitions.
- Side Kick, front and back, 8 per side.
- Something standing: 30 seconds on one leg per side, close to a wall.
Then test it where it counts. Next time you lift a full laundry basket, breathe out as you lift, keep your ribs soft and notice whether your middle holds without you holding your breath. That small moment by the washing machine is what all the mat work is for.
