Exercise when everything hurts: what actually helps with AS

The thing that took me the longest to accept about AS — and I have heard this from almost everyone who has had it for a few years — is that movement is medicine.

Every instinct in your body says the opposite. You are in pain. Pain usually means: stop, protect, rest. And you do that, and you wake up the next morning barely able to get out of bed.

It is not that rest does not feel better in the moment. It often does. It is that the aftermath of rest is worse. The inflammation in AS is activity-responsive — it increases with immobility and decreases with movement. Your rheumatologist will tell you this. Every person who has lived with AS for more than a couple of years will tell you this. And it still takes most of us a year or two to genuinely believe it.

Why rest makes AS worse

AS inflammation is different from mechanical pain. A strained muscle needs rest to heal. The inflammation in your sacroiliac joints and spine does not work that way. The morning stiffness that defines AS — sometimes called the 'AS morning' — is worst after a night of lying still. It is the body's inflammatory system going unchecked during inactivity.

Movement breaks the cycle. It does not eliminate the inflammation, but it disperses the stiffness, gets blood moving, and activates the muscles that support your spine. An hour of gentle walking does more for your morning than an extra hour of lying in bed.

What the evidence supports

Swimming

Swimming is the most studied and most broadly recommended exercise for AS. The water supports your joints, removing the axial load while still providing resistance for muscle building. Warm water specifically helps with stiffness — the heat has an anti-inflammatory-adjacent effect. Many rheumatologists list swimming as their first recommendation above any other exercise.

If you have access to a heated pool, even 20-30 minutes twice a week makes a measurable difference. Hydrotherapy classes, where they exist, are particularly good because they are designed for people with exactly this kind of joint issue.

Yoga and Pilates

Both have solid evidence in AS. Yoga improves flexibility, body awareness, and breath — the breathwork is particularly relevant because AS can reduce chest expansion over time. A 3-month yoga programme in one study produced significant improvements in disease activity scores and quality of life.

Pilates focuses on core strengthening, which directly supports the spine. Yearlong Pilates studies have shown dramatic improvements in functional scores in AS patients. The key is finding a teacher who knows about spinal conditions and can adapt postures safely.

Walking

The lowest barrier, the most consistent, and genuinely evidence-backed. Walking improves cardiovascular health, maintains spinal mobility, and — critically — is something you can do every day. The research on AS exercise consistently shows that consistency matters more than intensity.

A 20-minute walk every day beats a 60-minute gym session once a week.

Strength training

Core strengthening in particular. The muscles along the spine — the paraspinals — take over load-bearing when the joints are inflamed. Strengthening them reduces the direct stress on your spinal joints. This is supported and widely recommended.

The caveat: if you have significant spinal fusion, heavy axial loading carries fracture risk. Your physiotherapist or rheumatologist should guide this if you have progressed disease.

The morning routine — what it actually looks like

The single most consistently recommended habit across every AS community I have been in: a stretch routine before you get out of bed.

This is not a metaphor. Literally, while still lying in bed, before you stand up. The goal is to gently move the joints while they are warm from sleep, before the inflammatory stiffness sets in completely.

A basic routine (10-15 minutes):

Lie on your back. Bring both knees gently toward your chest and hold for 10 seconds. Let them down. Pelvic tilts — flatten your lower back against the mattress, then gently arch it. Alternate for 10 repetitions. Bend one knee and let it fall gently to the side, then bring it back. Repeat other side. Roll to your side slowly, and push yourself up to sitting from there — do not sit straight up.

It sounds minor. After a few weeks of doing it consistently, you will notice that the first hour of the day is meaningfully less difficult.

How to exercise on a bad day

This is where most advice fails people. 'Exercise is important' is easy to say. But what do you do when you are in active pain?

The answer is not: do nothing. The answer is: do less than usual, but do something.

On a bad day, a 5-minute walk around the block is meaningful. 10 minutes of gentle stretching in bed is meaningful. The goal is to break the cycle of complete immobility, not to hit a training target. Anything that moves the body and keeps the joints from settling into stiffness is useful.

The psychological part is harder. Pain is demotivating. When you feel terrible, motivation to move is near zero. The way I frame it: I am not exercising because I want to. I am exercising because I know what happens when I don't. That is a different kind of motivation, and it is the kind that sustains over years.

What to avoid

High-impact exercise — running on hard surfaces, contact sports, heavy axial loading — is generally not recommended, especially for people with progressed disease. The risk of stress fractures is real.

Exercises that require extreme range of motion before warming up properly. Cold, stiff joints do not want to be pushed into their limits first thing in the morning. Warm up first.

The exercise you hate. If you loathe swimming, you will not swim consistently. Find something you can sustain.