How Much Pain Is OK During Rehab Exercise?

A 2026 shoulder tendinopathy trial showed patients really can stick to a pain limit they are given — but which limit works better is still unknown.

📎 Looking for the full loading program? See → Tendinopathy Rehab — Exercise Progression & Program

What did this study find?

If you are doing shoulder or tendon rehab, the question comes up almost every session: “Am I allowed to feel pain? And how much is too much?”

A trial called PASE was designed to answer exactly that. It is a randomized controlled trial — patients are split into groups by chance, which is one of the most reliable study designs we have.

• It enrolled 84 people with long-standing rotator cuff tendinopathy — pain in the tendons deep in the shoulder, usually from overuse.
• Everyone did the same standardised physiotherapy program for 26 weeks. The only difference between the two groups was how much pain they were allowed during the exercises:
  • Pain-allowed group: pain up to 5 out of 10 was fine (on a 0–10 scale, where 0 is no pain and 10 is the worst imaginable).
  • Pain-avoidance group: keep pain below 3 out of 10.

The new 2026 paper looks at one specific question: could patients actually do it? (Researchers call this adherence.)

• Average pain during exercise was 2.8 in the pain-allowed group and 1.6 in the pain-avoidance group — a clear, statistically significant difference.
• In other words: people really can follow a pain limit they are given. That sounds obvious, but it had never been shown prospectively before.
• Other adherence numbers:
  • 75% of patients attended at least 6 of their 8 physiotherapy sessions.
  • Pain logbook completion fell from 76% to 68% over the 26 weeks.
  • Exercise logbook completion fell from 75% to 61%.
  • Most of the drop came after week 20 — exactly when the supervised physiotherapy sessions ended.
• Adherence was no different between the two groups. Being allowed to work into pain did not make people quit sooner.

What it means for you

• A pain limit is a workable instruction. When a physiotherapist says “stay under 5” or “keep it below 3,” that is something patients can genuinely act on.
• Supervision helps you keep going. Logbook completion only dropped off after supervised sessions ended. Scheduled follow-up — or simply a training partner — makes it easier to finish a long program.
• Pain during exercise in chronic tendinopathy does not mean you are damaging tissue. That distinction matters a lot.
• This fits the wider evidence on tendon rehab:
  • In Achilles tendinopathy, a pain-monitoring approach that let people keep running and jumping did no harm compared with resting from sport. Both groups improved on the VISA-A score (a tendon function questionnaire — higher is better) from 57 to 85–91 at 12 months.
  • A large evidence synthesis covering 204 studies concluded that exercise therapy for tendinopathy is safe and beneficial.
• But read the limitations section below — this study does not tell us which pain limit gives better results.

How to apply it

• Pick one threshold and stay with it. Current evidence supports allowing pain up to 5/10 during exercise. Staying below 3/10 also works.
• Consistency matters more than the number. Sticking to whichever limit you chose is more important than choosing 3 versus 5.
• Score your pain 0–10 during each session. Jot it on your phone or on paper — it takes seconds.
• Two safety checks:
  • Pain should not be clearly worse the next day.
  • Pain should not linger in a way that interferes with function — dressing, sleeping, working.
• If either check fails, that session was too much. Reduce the load, reps, or range — don’t stop altogether.
• Don’t shut training down just because it hurts. Tendons get weaker with rest, and pain tends to return when you go back to activity.
• Learning about pain genuinely helps. Pain science education combined with exercise reduced movement-evoked pain by about 3 points and lowered fear of movement. Understanding your condition and believing you can manage it (self-efficacy) are both linked to better outcomes.
• Set your threshold with your physiotherapist or doctor, especially if you have a significant tear, recent surgery, or severe pain.

Limitations of this study

The most important point: the trial’s main result is not out yet.

The question PASE was really built to answer — which pain threshold produces better outcomes — has not been published.

This 2026 paper only shows that patients can follow an assigned threshold. It says nothing about whether allowing pain beats avoiding it, or the reverse. Any claim that “new research proves rehab should hurt” is overstating it.

Other limitations:

• This is a single trial with 84 participants — a modest size.
• Participants had chronic rotator cuff tendinopathy. The findings may not transfer to other body regions, to post-surgical rehab, or to fresh injuries.
• Pain scores were self-recorded, so recall and reporting gaps are likely — and logbook completion itself was only around 60–75%.
• Follow-up ran 26 weeks. What happens longer term is unknown.
• Although average pain differed between groups (2.8 vs 1.6), both were below their own allowed ceilings — in practice, nobody was exercising near the top of their limit.

Frequently asked questions

Q: So should I work into pain during rehab, or avoid it?

• There is no settled answer yet, because the head-to-head outcome results have not been published.
• Both approaches are reasonable options: up to 5/10 is acceptable, and staying below 3/10 also works.
• Practical advice: agree on a threshold with your therapist, then apply it consistently, using the “no worse the next day, no loss of function” checks as your guardrails.

Q: If exercise hurts, am I making the tendon worse?

• In chronic tendinopathy, pain during exercise does not equal tissue damage.
• The real warning signs are pain that is clearly worse the following day, or pain that persists and interferes with daily function.
• Avoiding all pain often means loading the tendon too lightly to build capacity.

Q: Why do I lose motivation to log and keep exercising later on?

• That is normal, and the study captured it: logbook completion slid from about 75% to 61%, and most of the drop came after supervision ended.
• So keep some form of follow-up in place — book review appointments, find a training partner, or simplify your log until it takes ten seconds.
• Understanding your own problem and believing the exercise is worthwhile also tracks with better outcomes. It is worth asking your clinician to explain your diagnosis properly.