You came in with a sore knee or a stiff back, and your plan now includes 20 minutes of walking or a stationary bike alongside the strengthening exercises. It can feel beside the point. It is not. Aerobic work has a place in most rehab programmes for three reasons: it reduces pain in its own right, it rebuilds the capacity to get through a day, and it is the part of the plan most likely to still be there in a year.
It reduces pain, about as well as anything else
A 2022 review in BMC Musculoskeletal Disorders gathered 45 systematic reviews covering nine types of exercise for chronic low back pain, from Pilates and yoga to resistance training and walking. Its conclusion was that no exercise type stood out: most produced small, mainly short-term reductions in pain and disability compared with doing little, and none was clearly superior. The one review of aerobic training found it reduced pain intensity about as well as resistance exercise. The practical reading is that the best exercise is one you will keep doing, and for many people that is a walk.
For knee, hip, and multi-joint osteoarthritis, the 2019 OARSI guidelines list structured land-based exercise, with education, as a core treatment for everyone, before any medication or injection. Aerobic and strengthening work both count.
It rebuilds capacity, not just the joint
Pain tends to shrink activity. Weeks of doing less leave you less fit, so ordinary tasks feel harder, which feels like the injury getting worse when it is partly deconditioning. Strength exercises fix the local problem; aerobic exercise fixes the general one. A patient who can walk 30 minutes comfortably has somewhere to put the stronger muscles.
How much is enough
The World Health Organization's 2020 guidelines ask adults for 150 to 300 minutes of moderate aerobic activity a week, or half that at vigorous intensity, plus strengthening on two or more days. For people with chronic conditions the guidance is the same target where possible, and otherwise to be as active as your abilities allow. The guidelines are explicit that some activity is better than none, and that people not currently active should start small and build frequency, then duration, then intensity. Your therapist's 20 minutes is a starting point on that path, not the whole prescription.
Doing it well with a sore joint
- Moderate means you can talk but not sing. If you can sing, go a little faster; if you cannot talk, slow down.
- Pick the surface and the kit for the joint. A bike or pool unloads a knee; a treadmill or flat pavement suits a back better than hills.
- Build time before pace. Ten minutes a day for a week, then fifteen, then twenty.
- Use the same pain rule as your other exercises: some discomfort during is fine if it settles after and is gone by morning.
- Count it. Minutes of cardio belong in your log alongside reps and holds, because your therapist will progress it the same way.
How KineTrue fits
Endurance and conditioning is one of the exercise categories a therapist can assign in KineTrue, alongside strength, balance, flexibility, and the body-region programmes, with a timer rather than a rep count. Your pain rating goes in the same place, so cardio sessions are reviewed with the rest. If sticking with it is the hard part, our guide to sticking to your prescribed exercise plan
If you have a heart or lung condition, are recovering from surgery, or have been told to limit exertion, check the type and amount of aerobic exercise with your therapist or doctor before starting. The WHO guidance says the same: where there are contraindications, activity should follow your treatment plan.