50%
This is the typical adherence rate for physical therapy home exercise programs (HEP) (1). While we harp on the importance of HEP, we have a challenge with adherence.
Other professions struggle with adherence too. It is estimated that around 50% of patients do not take their medications as prescribed (2). And this includes medications for significant medical conditions such as cancer and cardiovascular disease. If it’s challenging to get people to quite literally take a pill, how can we expect people to stick to an HEP?
Thankfully, there are a couple studies in the research literature. While many factors can improve exercise adherence, one of the fastest to implement is simple: limit the number of exercises in an HEP.
First, Medina et al in Spain, studied patients with chronic neck and/or back pain (1). The patients were evaluated and given a plan of care, including HEP. After 1 month, adherence was assessed. There was a statistically significant difference in adherence for those given more than 6 exercises as compared to those who were given 3 or fewer exercises. Patients who were prescribed more than 6 exercises were less likely to adhere to HEP.
Then Eckard et al, studied U.S. military service members with various orthopedic pain complaints (3). The service members were evaluated and given a plan of care, including HEP. After prescribing HEP, compliance was assessed 4-14 days later. There was a statistically significant difference in compliance for those receiving 2 or fewer exercises (86%) and those receiving 4 or more exercises (54%).

Overall, these studies suggest that giving too many exercises decreases adherence. A likely upper “limit” would be about 6 exercises, with 1-3 seeming to be the sweet spot. Of course, these are not strict limits, but rough guidelines.
I think using fewer exercises actually demonstrates more skill and asks more of us as therapists. A mentor of mine commented that especially now with the doctorate level education, we should pick the few essential exercises, not throw a laundry list of exercises at patients. I couldn’t agree more.
Besides better adherence, a streamlined HEP helps us troubleshoot. If we give a patient 7 exercises and they come back with significantly increased pain, it’s hard to know how to adjust the HEP. There are simply too many variables.
In short: focusing on the few essential exercises sets us and our patients up for success.
References:
1. Medina-Mirapeix, F., Escolar-Reina, P., Gascón-Cánovas, J. J., Montilla-Herrador, J., Jimeno-Serrano, F. J., & Collins, S. M. (2009). Predictive factors of adherence to frequency and duration components in home exercise programs for neck and low back pain: an observational study. BMC musculoskeletal disorders, 10, 155. https://doi.org/10.1186/1471-2474-10-155
2. Brown, M. T., & Bussell, J. K. (2011). Medication adherence: WHO cares?. Mayo Clinic proceedings, 86(4), 304–314. https://doi.org/10.4065/mcp.2010.0575
3. Eckard, T., Lopez, J., Kaus, A., & Aden, J. (2015). Home exercise program compliance of service members in the deployed environment: an observational cohort study. Military medicine, 180(2), 186–191. https://doi.org/10.7205/MILMED-D-14-00306