The stiffness you blame on age is mostly a shortage of movement. Your body was built to do far more than sit.
Here is a quietly liberating idea: a great deal of the stiffness you have been blaming on your age is not really about your age at all. It is about your decade of chairs. The human body keeps the range of motion it regularly uses and slowly surrenders the range it does not, and modern life has narrowed our movement to a startling degree. We sit to commute, sit to work, sit to eat, sit to rest. We move through a tiny fraction of the positions our bodies are designed for, and then we are surprised when we cannot squat to the floor or reach overhead without complaint. The body did not break. It simply adapted to the small box we gave it.
This is the insight at the heart of functional movement and mobility work, and it reframes the whole problem. Mobility is not the same as flexibility. Flexibility is passive, how far a limb can be stretched. Mobility is active, how much usable, controlled range you actually own and can move through under your own power. You can be loose and still weak at the edges of your range; you can be strong and still locked. Mobility work builds the thing that actually matters for a capable body: strength and control across the full range you were designed to use. It is not about becoming a contortionist. It is about reclaiming the ordinary human movements, squatting, hinging, reaching, twisting, carrying, that a sedentary life has quietly taken from you.
The teachers who have shaped this field describe it almost as a nutritional problem. Katy Bowman, the biomechanist, argues in Move Your DNA that we are not just under-exercised but under-moved, that we need a varied diet of movement throughout the day rather than one concentrated workout to atone for hours of stillness. A short, intense gym session, valuable as it is, does not undo the cellular cost of sitting for eleven hours; the body needs movement spread across the day, in many shapes, the way it always had it. Kelly and Juliet Starrett make a related case in Built to Move, focusing on a handful of essential capacities, getting up and down off the floor, breathing well, walking enough, that predict how freely you will move as you age. The thread through all of it is the same: the body is a use-it-or-lose-it instrument, and most of us have been losing it without realising there was a choice.
What does the work actually look like? Less like a punishing workout and more like a deliberate reclaiming. A good mobility or functional movement coach assesses where your range has narrowed, then gives you specific work to open and strengthen those territories: hips that have forgotten how to fold, shoulders that no longer reach overhead cleanly, ankles and spines stiffened by years of the same few positions. They teach you to move well, not just to move more, because quality of movement is what protects you. And crucially, they build the habit of movement back into your day, so the gains hold. This is some of the most practical work in the whole wellness world, because it pays off in the smallest moments: bending to lift a child without fear, sitting on the floor and rising without a hand, carrying the shopping up the stairs and not thinking about it.
There is a longevity argument here too, and it is not abstract. The capacity to move freely, to get off the floor unassisted, to keep your range and your strength, is one of the clearest predictors of how independent and how mobile your later decades will be. The stiffness you tend to now is a deposit toward the body you will live in at seventy. The good news in that sentence is the agency hidden inside it. Range that has narrowed can, in most cases, be widened again. The body is remarkably willing to give back what it took away, if you simply start asking it to move through more of itself.
So if you feel older in your body than you would like, do not assume the door has closed. You are probably not stiff in the way you fear. You are under-moved, which is a far more hopeful diagnosis, because it has a remedy, and the remedy is to move through more of the body you already have.
To reclaim the range you assumed was gone, find your guide.
