Antwon was tasked recently with looking up evidence on the 2x vs. 3x a week frequency and its effect on outcomes, and he dug around Google Scholar for something substantial. He did find an article on chronic pain outcomes (which the results may surprise you), but he had quite a few criticisms on the article itself. We did have a discussion on other articles on the topic (acute injuries, chronic pain, post-surgical cases) and how frequency may be more suggestive then, but go ahead and read on for what Antwon found:
Antwon: A study was conducted to determine the effectiveness of a spine therapy program being delivered two times per week compared to three times per week. Of the 77 participants, 24 chose to receive treatment two times per week, while 53 chose to receive treatment three times per week. Presenting characteristics were similar between both groups at the evaluation in the areas of mean duration of symptoms, sex, presenting diagnosis, and types of insurance. The only notable difference was an average age of 45 years old for the two times per week group versus 40 years old for the three times per week group. Analysis at discharge and at 12-month follow-up showed that pain and functional measures were similar for both groups. Analysis at discharge and at 12-month follow-up showed that performance levels for physical functional tests measures were similar for both groups. The results of the study suggests that physical therapy using aggressive exercise for the treatment of chronic spinal pain produced similar results for physical measures of flexibility and strength, subjective measures of pain and disability and for perception of adequacy of care, regardless of whether treatment was delivered two or three times per week.
Source:
Rainville, J., Jouve, C. A., Hartigan, C., Martienz, E., Hipona, M. (2002). Comparison of short and long term outcomes for aggressive spinal rehabilitation delivered two versus three times per week. The Spine Journal, 2:402-407.