We built furniture that shortened us

Count the seats in a training day. You wake up and sit down for breakfast. You sit in the car or on the train to work, then at a desk for most of the day, then in the car again. In the evening you go for a ride, and the saddle holds you bent forward for an hour and a half. Then you sit down to eat, and you finish the day on the sofa.

That is a good day. You trained. But from the moment you got up, your hips spent almost every hour folded at about a right angle, and your back spent most of it rounded forward. The seats changed. The shape did not.

Rest used to move you.

For most of human history, people rested on the ground. In the 1950s, the anthropologist Gordon Hewes gathered reports of how people rest from hundreds of cultures around the world. Deep squatting turned out to be one of humanity's most common ways to take the weight off its feet, and the chair a minority habit. Across much of Asia and the Middle East, people still squat, kneel and sit cross-legged every day. Those positions ask far more bend of the hips and knees than a chair ever does.

The squat is not magic. In a study of older people in Beijing, those who had squatted for two hours or more a day as young adults had about twice as much arthritis in the knee. Holding any one position for hours has a cost. What the ground gives you is variety. Rest on the ground, and you keep changing shape: squat, kneel, sit, lie back, shift again.

A chair holds one shape.

One shape, all day.

Your body gets good at what you do most. Spend most of the day with your hips shut and your back rounded, and that shape becomes easy while the others slowly close.

The hips pay first. When researchers measured the joints of adults of all ages, most had lost only a few degrees of range with age. Hip extension was the exception: the movement that swings your leg out behind you. The oldest group had lost more than a fifth of it. In another study, people who sat for more than seven hours a day had less of that same movement than active people who sat less. It is a link rather than proof, but it points one way.

For an endurance athlete, that movement matters. Every running stride pushes the leg out behind you. Lose the range, and the stride gets shorter or the lower back bends to make up the difference. And training does not give it back. A ride holds the same folded shape as the desk chair, for hours. A run moves the legs forward and back through a small arc, many thousands of times, and asks for little else: no twisting, no reaching overhead, no deep squat.

This is not about bad posture. The research does not find that a rounded back or a forward head, on their own, cause pain. The problem is not the shape you sit in. It is that you hold one shape so often that the others go missing.

Try this.

Stand with your feet flat and lower yourself into a deep squat, heels down, as low as you can go. Then stay there for a minute.

Then lie on your back on the floor, hug one knee to your chest, and let the other leg lie long. Does the straight leg stay flat on the floor, or does it lift?

For people who rest on the ground, the squat is a place to sit, and the long leg stays down. For many adults raised in chairs, and many endurance athletes, neither comes easily. That is the chair and the saddle, showing up in your hips.

Limit the damage.

Nobody is going to give up the chair, the car or the bike. Nor should you. But you can stop holding one shape for so long.

Break the shape often. Stand up every half hour or so, even for a minute, and let your hips open. Vary how you rest: sometimes on the floor, sometimes kneeling, sometimes cross-legged. Stand for a phone call. After a long drive or a long ride, walk for a few minutes before you sit down again. None of this is training. It only stops the day from being one shape from morning to night.

Undo it.

Then give your body back the movement it did not get. The chair and the saddle did not shorten one muscle. They shortened a whole shape. So a single stretch for one tight muscle will not fix it. Your body needs to move again through everything the day left out.

Open the front of the hips: sink into a long lunge, back leg reaching behind you, and feel the hip the saddle held shut. Move the spine every way it can go: round it, arch it, turn it, bend it to the side. Go wide with the legs, because nothing in a chair or on a bike lets you be wide. Reach your arms overhead. And spend time in the deep squat, with your heels down.

Do it with calm breathing, and never chase range you cannot breathe through. The aim is not to feel stretched out. It is to feel free to move. In our method, that is what yoga is for. It is the foundation of the pyramid, practised as often as the endurance on top of it, not left for the day you have spare time.

Every year adds to it.

Range you do not use closes slowly, and it does not stop closing by itself. Each year in the same shape adds a little to the last, and it adds up across a training life.

It can be slowed, and some of it can be won back. Studies of flexibility training in people over 65 find it improves range, though the evidence is still thin. That is no reason to wait. The easiest range to keep is the range you still have.

What this means for you

A life of chairs takes your mobility, and your training does not give it back. The bike holds the same shape as the desk, and the run asks for only one small part of what your hips can do.

So limit the damage: break the shape often, and rest in more than one position. Then undo it: move through everything the day left out, as part of your training, every week.

Every year makes it worse unless you work to keep it. Pursue mobility actively, and you stay mobile, and feel good, into old age.

Sources

Hewes 1955. American Anthropologist 57:231-244. Resting postures across cultures. (The quarter-of-humanity estimate is from his 1957 Scientific American article.)
Mulholland and Wyss 2001. International Journal of Rehabilitation Research 24:191-198. The hip and knee range that squatting, kneeling and cross-legged sitting need.
Zhang et al. 2004. Arthritis and Rheumatism 50:1187-1192. Squatting and knee arthritis in Beijing.
Roach and Miles 1991. Physical Therapy 71:656-665. Hip and knee range across ages 25 to 74.
Boukabache, Preece and Brookes 2021. Musculoskeletal Science and Practice 51:102282. Sitting time and hip extension.
Richards et al. 2016. Physical Therapy 96:1576-1587. Sitting posture and neck pain in teenagers.
Slater et al. 2019. Journal of Orthopaedic and Sports Physical Therapy 49:562-564. Posture and pain.
Stathokostas et al. 2012. Journal of Aging Research 2012:306818. Flexibility training in older adults.