Factors Associated With Inter-individual Variability In Response To Community-based Exercise In A Diverse Chronic Disease Population

PURPOSE: Community-based exercise rehabilitation (CBER) improves health outcomes for individuals with chronic disease (CD), yet up to 30% of participants show no response. Identifying factors linked to this variability could help reduce non-response rates and enhance CBER effectiveness. METHODS: Individuals with various CD were recruited at induction to a CBER program. Participants were advised to attend biweekly classes and were assessed at baseline (BL) and 12 months. Outcome measures included objective assessments of physical activity (PA), cardiorespiratory fitness (CRF), strength, body composition, and mental health. A measurable improvements was defined as an improvement of ≥0.01. Binary logistic regression models analysed factors associated to achieving measurable health improvements. RESULTS: A total of 206 participants (62.9 ± 11.0 yrs, 50.6% male) completed the study. A positive measurable change in ≥1 health variables was achieved by 92.2% of participants, with 86.4% showing improvement in 1 outcome while being non-responders in another. For measures of light intensity PA (OR = 0.19, p = .005), lower-body strength (OR = 1.13, p = .006), upper-body strength (OR = 0.90, p < .001), waist circumference (OR = 1.04, p = .025), symptoms of depression (OR = 1.37, p < .001) and satisfaction with life (OR = 0.89, p < .001), a worse result at BL, increased likelihood of achieving a measurable change. Higher CRF at BL increased the likelihood of achieving a measurable change in this measures (OR = 1.01, p = .022). Older age predicted lower likelihood of improvement in CRF (OR = 0.93, p = .008), handgrip (OR = 0.95, p = .011), and self-rated health (OR = 0.94, p = .028). Women were less likely to improve upper-body strength (OR = 0.18, p = .001). Metabolic and respiratory disease diagnoses reduced odds of improvement in light intensity PA (OR = 0.07, p = .027) and self-rated health (OR = 0.01, p = .002), respectively, while cancer patients had higher odds of improvement in lower-body strength (OR = 8.17, p = .036). CONCLUSION: Inter-individual variability exists in response to CBER. Lower PA, strength, and psychological health predict a positive response, while low CRF could result in non-response. Tailored introductory programs for at-risk individuals could improve CBER effectiveness as a secondary prevention service for CD.