I've been in and around physical training for over 37 years. Started as an athletics and boxing coach at 18 — before I knew anything about functional medicine, before I'd heard of metabolic typing, long before I had letters after my name. And the thing that strikes me now, looking back across all those years on gym floors, athletics tracks, and in clinic rooms, is this: we have become remarkably sophisticated at measuring the quantity of exercise while remaining almost completely blind to its quality.
We talk about food in exactly the same way. Calories in, calories out. Macros tracked to the gram. But we've started — slowly — to understand that the quality of food matters as much as the quantity. That 200 calories of salmon and 200 calories of a processed cereal bar are not remotely the same thing inside your body. That the question isn't just how much but what kind.
Exercise deserves the same conversation. And it's long overdue.
"In nutrition we've started asking about quality. It's time we asked the same question about movement — not how much did you do, but how well did you do it?"
The Quantity Trap
Walk into most gyms and here's what you'll hear. How many sets? How many reps? What weight are you lifting? How many kilometres did you run? How many calories did you burn? These are the currencies of exercise, and to be fair, they're not useless — volume and progressive overload matter. But they're the starting point, not the whole story, and somewhere along the line we've confused the measure with the goal.
I've worked with clients who were running 40 miles a week and couldn't touch their toes. People who could bench press serious weight but couldn't get into a deep squat without their heels lifting off the floor. Athletes who trained daily and still had chronic hip pain that nobody had traced back to the way they were actually moving.
The quantity was impressive. The quality was another matter entirely.
And this isn't just an aesthetic or performance issue. Movement quality has direct implications for how your body functions, how it ages, where pain originates, and — critically for my clinical work — how well it can adapt to stress. The body doesn't separate the stress of poor movement mechanics from the stress of a difficult week at work, a difficult gut, or a difficult hormone pattern. Stress is stress. Load is load. And cumulative load on a poorly moving body adds up.
What Movement Quality Actually Means
When I talk about movement quality I'm talking primarily about range of motion with control. That's the key phrase, and both words matter equally. Range of motion without control is just hypermobility — and hypermobility without the stability to match it is an injury waiting to happen. What we're after is the ability to move through a full, appropriate range while maintaining structural integrity throughout that range.
Think of a squat. Most people can do a squat of some kind. But the difference between a shallow quarter-squat performed with compensatory forward lean, and a full, deep squat with an upright torso, neutral spine, knees tracking correctly over the toes and the whole movement expressing genuine hip mobility combined with genuine ankle mobility combined with genuine core stability — that's not a small difference. That's the difference between a movement pattern that builds you up and one that slowly tears you down.
Range of motion with control is built from a combination of physical qualities. Get any of these wrong and the quality of your movement suffers — regardless of how much you're doing.
These aren't separate departments. They're an integrated system, and in good movement they work together seamlessly. Stability enables mobility. Flexibility contributes to range. Strength through range requires both. Power is the product of strength and speed — and it only expresses safely when the underlying quality is there to support it.
The Technique Problem
There's a knowledge component here that often gets overlooked. You can't move well if you don't know what well looks like — and most people have never been taught. Not really. You might have been shown a movement once, briefly, by someone who wasn't a coach. You might have watched a YouTube video. You might have been doing it the way you've always done it because nobody ever told you otherwise.
Good technique is a skill. And like every other skill, it requires instruction, practice, feedback, and refinement over time. It doesn't happen by accident, and it doesn't come automatically from just doing more of the thing. In fact, doing more of a poorly executed movement pattern is one of the most reliable ways to embed that pattern more deeply and make it harder to shift later.
This is where coaching matters enormously — and I say that having been a coach long before I was a clinician. The eye of someone who knows what they're looking for, giving timely and accurate feedback at the right moment, is worth more than any amount of solo training performed with compromised mechanics.
In functional medicine terms, exercise falls under the E in Reed Davis's DRESS model — Diet, Rest, Exercise, Stress reduction, Supplementation. It's one of the five foundational lifestyle pillars, not an optional extra. But exercise done poorly adds physiological stress rather than reducing it. It can drive cortisol, disrupt sleep, create inflammatory load, and contribute to a system that's already struggling.
For clients in the TDG programme — particularly those with HPA axis dysregulation or compromised gut integrity — the quality and appropriateness of their exercise is as much a clinical consideration as their supplement protocol.
Why This Matters More Than You Think
Poor movement quality has a long tail. It tends to be quiet for a while, then suddenly not. You accumulate small compensations — a hip that sits slightly off, a shoulder that rides a little high, a knee that tracks inward fractionally on every squat — and for months or years these compensations stay below the threshold of obvious pain. The body is extraordinarily good at working around its own limitations. Until it isn't.
By the time pain appears, the underlying movement dysfunction is often well established. Which means the pain is the last thing to show up and, usually, the last thing to resolve. Treating the pain site without addressing the movement pattern that created it is a bit like mopping the floor while the tap is still running.
There's also the aging dimension. The physical attributes that underpin quality movement — mobility, stability, strength, power — all decline with age if they're not trained. And critically, power declines fastest. The ability to produce force quickly, which is exactly what protects you from falls and sudden loads, starts declining in your 40s and accelerates from there. The people who maintain this capacity into their 60s, 70s and beyond are overwhelmingly the people who trained it intentionally. It does not maintain itself.
The Whole-Person View
At Detective Health, the whole job is never just one thing. Diet matters. Sleep matters. Stress reduction matters. Supplementation — where indicated, based on testing — matters. And exercise matters. Not exercise as a calorie-burning transaction, not exercise as punishment for eating, but exercise as a genuine investment in the physical capacity of your body to function, adapt, and perform across your lifespan.
That means asking not just what you're doing but how you're doing it. Whether the movement patterns you're reinforcing day after day are building you up or quietly wearing you down. Whether the quality of what you're doing matches the quantity.
In a world saturated with fitness content that tells you to do more, go harder, track more numbers, I think the more useful question is often simpler. Before you add another session, before you increase the load, before you log another mile — how well are you actually moving?
That question, honestly answered, is where real progress starts.
Stephen Duncan is an Edinburgh-based functional medicine practitioner. He has 37+ years of experience in health, fitness, and clinical practice, beginning as an athletics and boxing coach and progressing through a BSc in Developmental Biology, a Postgraduate Certificate in Health Informatics, and an MSc in Coaching Studies with Applied Physiology. The movement quality assessment is part of the TDG Five-Test Programme.