Why my physio tells me to move when I'm in pain

The paradox of movement when you are in pain

Your back hurts. Your shoulder aches. Your knee is throbbing. You go to your physiotherapist hoping for a massage, some heat therapy, a machine that will fix things. And your physio says: "You need to move." Worse, they give you exercises. Exercises that sometimes provoke a bit of pain while you do them. Every instinct screams that this is absurd. Why move something that hurts? Will it not make things worse?

This reaction is normal. It is hardwired into our biology. Pain is an alarm signal that drives us to protect the injured area. Staying still, avoiding painful movements, limiting effort: this behaviour saved our ancestors when they broke a leg on the savannah. But in the context of persistent pain, this protective reflex becomes the problem itself.

This guide explains why movement is, in the vast majority of cases, the most effective treatment for pain. Not any movement. Not any dose. But adapted, progressive, guided movement.

Pain is not a reliable indicator of tissue damage

This is the hardest point to accept, and the most important. Pain is not a damage meter. It is a protection system. The brain constantly evaluates incoming information: nerve signals, the context of the situation, memories of past experiences, emotions, beliefs. If the brain concludes the body is in danger, it produces pain. If the brain concludes the threat is low, pain decreases or vanishes.

A simple example. A soldier wounded in combat can run hundreds of metres without feeling pain, because his brain judges that immediate survival outweighs wound protection. Conversely, a person who had a disc herniation five years ago may feel intense pain bending to pick up a pen, even though their MRI now shows nothing abnormal. Their brain learned to associate back flexion with danger and keeps sounding the alarm in the absence of any lesion.

In 1995, a study published in the New England Journal of Medicine showed that 64% of adults with no back pain had disc abnormalities on MRI. Bulges, protrusions, sometimes herniations. Without pain. The state of the tissue and the experience of pain are not the same thing.

The vicious cycle of prolonged rest

When pain persists, instinct pushes us to reduce activity. The less we move, the less we hurt. Or so we think. But here is what actually happens in the body when we stop moving.

Muscles weaken. In a single week of immobilisation, a muscle can lose up to 5% of its strength. Tendons lose their elasticity. Joints stiffen. Intervertebral discs, which rely on pressure changes from movement for their nutrition, dehydrate. Tissues become less resilient and more sensitive to even small loads.

The tolerance threshold drops. What was painless before the rest period now triggers pain. Not because the injury has worsened, but because deconditioned tissues protest under a load they used to handle without complaint.

The brain interprets this new signal as confirmation of danger. It strengthens protection. The person reduces activity further. Muscles weaken more. The threshold drops again. It is a downward spiral.

Researchers call this phenomenon deconditioning. It affects people with chronic low back pain, neck pain, persistent tendinopathies, fibromyalgia. It is not a moral judgment about willpower. It is a physiological mechanism that kicks in automatically when movement decreases.

Why movement works as a painkiller

Movement triggers a cascade of physiological reactions that reduce pain. This is not a metaphor. It is biochemistry.

During exercise, the body releases endorphins, opioid molecules produced naturally by the nervous system. These endorphins bind to the same receptors as morphine. The analgesic effect of a moderate exercise session lasts between 30 minutes and several hours.

Movement also activates pain-modulation systems at the spinal cord level. The tactile and proprioceptive signals generated by movement "close the gate" to nociceptive signals (danger signals). This is the gate control theory, proposed by Melzack and Wall in 1965. It explains why rubbing a sore spot brings temporary relief, and why moving a stiff joint reduces pain.

Exercise also lowers systemic inflammatory markers. Low-grade chronic inflammation, present in many persistent pain conditions, decreases with regular physical activity. Pro-inflammatory cytokines (IL-6, TNF-alpha) drop. Anti-inflammatory cytokines rise.

Finally, movement improves local blood flow. Tendons, ligaments and intervertebral discs are poorly vascularised tissues that depend on movement to receive nutrients and oxygen. Moving literally feeds the structures in distress.

Kinesiophobia: when the fear of movement becomes the real problem

Kinesiophobia is an irrational, excessive fear of movement, driven by the belief that movement will cause re-injury or worsen pain. It affects between 50 and 70% of people with chronic pain. It is one of the strongest predictors of the transition from acute to chronic pain.

Kinesiophobia does not mean a person is weak or cowardly. It is a learned response. The brain has linked certain movements with pain and danger. Every time the person avoids the dreaded movement and pain does not appear, the brain reinforces the idea that avoidance was the right strategy. The protective behaviour becomes a trap.

Treating kinesiophobia requires graded exposure. The body is gradually reintroduced to movement, starting with activities perceived as low threat, and the load and complexity increase slowly. Each successful movement without catastrophe sends the brain a message: "This is not dangerous." Over time, confidence returns.

Studies show that pain education combined with graded exposure is more effective than passive treatments (massage, electrotherapy, rest) for persistent musculoskeletal pain. Patients who understand why they hurt adhere better to their rehabilitation programme and achieve better outcomes.

Moving does not mean suffering

The instruction "you need to move" can be misinterpreted. Some people understand it as pushing through pain, gritting their teeth, ignoring their body's signals. That is not the message.

Moving with pain means finding the right dose. Physiotherapists often use the "3 out of 10" rule: during an exercise, pain at or below 3 on a 10-point scale is acceptable. Above that, reduce the intensity. If pain increases in the 24 hours following exercise and does not return to baseline, the dose was too high.

The goal is to find the zone of optimal stimulus. Too little movement does not produce enough stimulation for tissues to adapt. Too much movement causes excessive irritation. The sweet spot sits between the two: enough to stimulate, not so much that it inflames. This point shifts over time. What was the upper limit last week becomes the starting point this week.

Some days are better than others. Pain fluctuates with sleep, stress, mood, the previous day's activity. On tough days, lower the dose without stopping entirely. On good days, push a little further. What matters is the trend over several weeks, not the performance on any given day.

The forms of movement most studied for pain relief

Walking

It is the most accessible form of movement and one of the most researched. Regular walking reduces low back pain, knee osteoarthritis pain, fibromyalgia symptoms and neck pain. It requires no equipment, can be done anywhere and suits every fitness level. 30 minutes a day, even split into three 10-minute blocks, produces measurable effects. Start with what you can tolerate, even 5 minutes, and build up gradually.

Strengthening exercises

Resistance training has a dual effect: it increases the load-bearing capacity of tissues (muscles, tendons and bones become more resilient) and it changes how the nervous system perceives pain. Meta-analyses show that strengthening is as effective as manual therapy for low back pain, and more effective in the long term. The ideal programme combines exercises targeting the painful area with global exercises that work the whole body.

Aerobic exercise

Swimming, cycling, using an elliptical trainer, dancing: any activity that raises the heart rate in a sustained way for 20 to 30 minutes produces a significant analgesic effect. Aerobic exercise activates the descending inhibitory pain systems and improves mood, sleep and functional capacity. For people with chronic pain, a progressive aerobic programme is one of the most effective interventions available.

Yoga and Pilates

These disciplines combine movement, breathing and body awareness. Research shows they are effective for chronic low back pain, neck pain and fibromyalgia. Yoga in particular reduces kinesiophobia by allowing people to re-experience movements in a calm, controlled setting. Pilates strengthens the deep trunk muscles and improves motor control.

How to start moving again when you are afraid

If you have stopped moving for a long time, getting started can feel daunting. Here is a step-by-step approach.

Choose an activity you enjoyed before the pain, or one you perceive as low risk. Not the one that scares you most. Begin with a ridiculously small volume. 5 minutes of walking. 3 simple exercises. The goal of the first week is not to progress: it is to prove to your brain that movement is safe.

Increase volume by 10 to 20% per week. If you walked 10 minutes without a flare-up, go to 12 the following week. If you did 2 sets of 10 repetitions, move to 3 sets. The progression must be slow enough to avoid triggering a pain spike, but steady enough to drive adaptation.

Keep a simple journal. Note the activity, duration, pain intensity during and after. Review it regularly. You will often find that pain fluctuates independently of exercise volume, which reinforces the idea that movement is not the cause of the problem.

Do not compare yourself to your pre-pain level. Compare yourself to last week. Every bit of progress, however small, counts.

When rest is genuinely necessary

It would be dishonest to claim that movement is always the answer. Some situations demand rest. An unhealed fracture, a joint infection, severe acute inflammation (a gout flare, for instance), a complete muscle tear in its first days: in these cases, rest protects a structure that needs time to heal.

The difference lies in the duration and nature of rest. Even in cases of acute injury, complete rest is rarely recommended beyond a few days. The term used is relative rest: protect the injured area while keeping the unaffected parts active. A broken arm does not prevent walking. Acute back pain does not prevent using a stationary bike if the position is comfortable.

The general rule: if your healthcare professional tells you to move, trust them. They are not telling you to move as a punishment or because they have nothing better to offer. They are telling you because the science shows, with striking consistency, that adapted movement is the most effective treatment for the vast majority of musculoskeletal pain.

What to take away

Pain is a protection signal, not a damage counter. Prolonged rest weakens tissues and lowers the effort tolerance threshold. Movement releases natural painkillers, nourishes tissues and recalibrates the nervous system. Fear of movement is normal, but it is treated through gradual exposure. Moving does not mean suffering: find the right dose and progress slowly. Your physio tells you to move because it is the treatment with the most scientific evidence behind it. Not because it is easy, but because it works.