The worst part about physical therapy is not knowing if it’s working. The timescale for improvement is dreadfully long and the day-to-day changes are imperceptible.

65% of people who start physical therapy fail to adhere to their prescribed regimen. One of the primary factors for non-compliance is the lack of positive feedback. Physical therapy goes against human nature and our desire for immediate results.

After developing a shoulder issue, I experienced the same thing many people do: performing seemingly useless exercises and hoping my shoulder would improve rapidly. Without noticeable progress, I quickly became one of the 65%. The whole thing just wasn’t satisfying enough for me to want to do it.

What changed, and finally healed my shoulder, was hiding my physical therapy in some peanut butter.

Growing up, my family dog refused to take her pills. But that changed when we started hiding her pills in peanut butter. Remembering this experience gave me an idea for physical therapy.

Hiding something in peanut butter: surrounding and hiding a difficult task between more enjoyable tasks.

While physical therapy sucks, I do enjoy lifting weights at the gym. I had taken a years-long sabbatical from the gym because of my injury. But I returned when I realized I could work out my lower body without irritating my shoulder. In between squat sets, I began sneaking in some rotator cuff work.

At the end of my workout, I rewarded myself by doing a chest press movement with the lightest of dumbbells that wouldn’t aggravate my shoulder.

I was already in the habit of writing my reps & sets in an exercise journal (thanks Tim Ferriss), so I also started recording my shoulder pain level each week.

What gets measured gets managed. — Peter Drucker

My hope was that while I may not feel a perceptible difference in pain day-to-day, perhaps over time a descending trend in my pain level would emerge.

I started at a pain level of ~3.5/10. After four months I became pain free. As author James Clear likes to say in his book Atomic Habits:

What is immediately rewarded is repeated. What is immediately punished is avoided.

Perhaps the reason physical therapy compliance is so low is because too much focus is given to the mechanics of exercises and not enough emphasis is placed on how behavior change happens. Hiding a difficult task between enjoyable tasks (for me that's exercise; your peanut butter may be something else) is one path to effective behavior change.