Movement as Medicine

Movement is one of the strongest signals you can give your body. It helps tell it to keep muscle, maintain bone, handle glucose and preserve the physical capacity you want later. And through midlife, those signals become more important — not less.

Your body adapts to what you ask it to do. Load your bones and they work to become stronger. Use your muscles and the body works to maintain them. Stop using either for long enough, and they begin to decline.

That is why movement matters far beyond fitness. Every walk, lift, climb and stretch sends a message: I still need this. Keep it working.

Many of the systems we spend money trying to optimise with supplements, tools and technology already respond powerfully to something completely free: using the body. Muscle, bone, blood sugar and the fluid moving through your tissues all change in response to movement — sometimes remarkably quickly.

This module looks at four of those responses: how movement helps fluid travel through your tissues, what happens to blood sugar after a meal, how bone responds to load, and how steady aerobic work builds stamina. Then we turn it into something you can actually use in a normal week.

Your blood has one central pump. Your lymphatic system works differently. Its collecting vessels are divided into small segments with one-way valves, and the muscle in the vessel walls contracts rhythmically to help move fluid forward. One segment squeezes, fluid moves through the valve, and the valve closes behind it.

But the system also gets help from movement. Working muscles compress lymph vessels from the outside, your diaphragm changes pressure as you breathe, and nearby arteries add their own pulsation. This is one reason long periods of sitting can leave your legs feeling heavier or puffier than a day spent walking.

And lymph is not simply “waste.” It carries excess fluid and proteins out of tissues, transports immune cells, helps move fats absorbed through the gut and eventually returns that fluid to the bloodstream.

Movement is not flushing toxins out of you. It is helping a real transport system do a job your body is already doing all day.

You already know what reduced movement can feel like: tighter ankles after a long flight, rings that fit differently after a day at a desk, or legs that simply feel better after ten minutes of walking.

Walking is the simplest way to bring regular muscle contraction back into the system. Rebounding is another option I like, especially indoors or when walking is not practical. Five or ten minutes is easy to fit into the day, but I think of it as another form of movement rather than a replacement for walking.

After you eat, sugar enters your bloodstream and needs somewhere to go. One of its main destinations is your muscles.

Normally, insulin helps move that sugar out of the blood and into muscle cells. It does this by bringing a transporter called GLUT4 to the surface of the cell. Think of GLUT4 as a door: the more doors available, the easier it is for sugar to leave the bloodstream and enter the muscle.

But movement gives your muscles another way to open those doors.

When a muscle contracts, it can move GLUT4 to the cell surface through signals created by the contraction itself — without waiting for insulin to do the job. That means working muscles can pull sugar out of the bloodstream even when insulin is not working particularly well.

A working muscle has another way to pull sugar out of your bloodstream — one that does not require insulin to do all the work. That is why a walk after dinner is not “just walking.” You are changing glucose handling in real time. Studies comparing prolonged sitting with standing and brief walking breaks found that both helped reduce the rise in blood sugar, but walking worked better.

And it does not take a workout. Even a few minutes of walking can make a difference. The contraction itself is enough to change what the muscle is doing with glucose.

In practice this is the easiest change in the whole module to make, because it attaches to something you already do three times a day. A short walk after dinner. Standing up and moving around the kitchen while you clear the table. Ten minutes outside after lunch instead of straight back to the desk. None of this requires deciding to exercise, which is precisely why it survives contact with a real week.

Bone is living tissue, and it is constantly rebuilding itself. Old bone is broken down and new bone takes its place.

What tells your body to build stronger bone is load. When bone is regularly challenged by weight, impact or resistance, it responds by becoming stronger. When that challenge disappears, bone gradually becomes weaker.

For bone, simply being active is not enough. Bone needs load. Walking is wonderful for almost everything else on this page, but if you want your skeleton to build, you have to give it a reason. Lift something heavy enough that the bone notices.

Duration barely enters into it. What bone responds to is how much force is applied, and how quickly — not how long you kept going. Walking does very little for the density of your hip and spine because the loads are small and already familiar to the skeleton. For bone, familiar movement is not a strong enough signal to build more.

Walking is excellent for many things, but bone needs a stronger signal.

In one of the most useful studies in this area, postmenopausal women with low bone mass lifted heavy weights twice a week for eight months. The sessions lasted about thirty minutes and included five sets of five repetitions using weights close to the heaviest they could safely manage.

Their spine and hip bone density improved compared with women doing a gentle home exercise programme.

This matters even more through perimenopause and after menopause. Oestrogen helps slow the breakdown of bone. As oestrogen falls, bone loss speeds up. Resistance training gives the skeleton a clear reason to keep building and maintaining strength.

And strength training gives you something else that becomes increasingly valuable through midlife: muscle.

Muscle helps clear glucose from the bloodstream, stores it for later use, burns energy even at rest, and releases signalling molecules when it works. So preserving muscle is not simply about looking toned. It is an important part of maintaining metabolic health as you age.

One surprisingly useful measure of this is grip strength. In a large study across seventeen countries, grip strength predicted mortality more strongly than blood pressure.

That does not mean you need to start training your handshake. Grip strength is useful because it reflects something much bigger: how much strength and muscle your body has managed to hold onto.

And that is really the goal. Not simply living longer, but staying strong and capable inside the years you have.

One of the simplest ways to build stamina is to spend time moving at a pace that feels steady, but not exhausting.

This is often called Zone 2. You are breathing harder than normal, but you can still speak in full sentences. Think brisk walking uphill, easy cycling, swimming, or anything else you can keep doing without needing to stop and recover.

Why does this matter? Because sustained aerobic movement tells your cells to build more mitochondria — the tiny structures that help turn food and oxygen into energy.

More mitochondrial capacity means your body becomes better at producing energy efficiently. Over time, that can look very ordinary: stairs feel easier, you recover faster, and everyday movement takes less out of you.

The useful part is that you do not need to go hard to get this effect. In fact, this kind of training works because the pace is sustainable enough to stay in for longer.

You can use heart rate as a rough guide, but your breathing is often simpler.

If you can speak in full sentences, you are probably close. If you cannot finish a sentence, ease off. If you could comfortably sing, pick up the pace a little.

That conversational effort is the zone you are looking for.

Anything that holds you at that pace counts, and the activity matters far less than the time accumulated in the zone. Walking uphill, swimming, cycling, dancing, pushing a pram up a slope — the body responds to sustained moderate demand, not to the equipment. Thirty to forty-five minutes, four or so times a week, is a reasonable target to build towards, and it need not arrive in one piece. The best version is whichever one you will actually repeat.

If you only take two things from this module, take the post-meal walk and the twice-weekly strength session. The walk costs almost nothing and attaches to something you already do; the lifting is the item here specifically aimed at preserving and building bone density, and walking does not substitute for it. Everything else below is genuinely good and genuinely optional.

It is also worth knowing how small the effective dose can be. Researchers using wrist monitors were able to pick out brief bursts of hard effort buried in ordinary days — hurrying up a flight of stairs, carrying shopping to the car, walking fast to catch a bus. Among twenty-five thousand people who did no formal exercise at all, some accumulated around three of these bursts a day, each lasting a minute or two. Their rates of death from all causes and from heart disease were markedly lower than in people who had none. The bursts were not workouts. Nobody changed clothes.

The useful dose of hard effort, then, is far smaller than the word exercise implies — and it need not arrive as exercise at all. If the twice-weekly session is not happening yet, this is a real place to start.

Most of the practical recommendations in this module come directly from human research. The physiology of lymphatic pumping is well established, and the effect of walking on blood sugar after a meal has been measured repeatedly across different labs. The bone section is built around well-run trials in postmenopausal women, including the LIFTMOR study, which gives us a strong practical signal even though that specific protocol has not yet been repeated at large scale.