Physical activity and transitioning to retirement: evidence from the China health and retirement longitudinal study

Background The impact of retirement on physical activity among older individuals remains ambiguous. This study aims to investigate the influence of retirement on physical activity and delineate the trajectories of physical activity changes during the retirement transition among elderly Chinese residents. Additionally, we endeavor to examine the factors that contribute to each trajectory. Methods This longitudinal cohort study used data from four surveys of the China Health and Retirement Longitudinal Study and included a sample of 428 individuals who underwent formal retirement and provided information on physical activity. We employed generalized estimating equation to explore the impact of the retirement transition on physical activity among Chinese older adults. Latent class growth analysis was used to identify distinct trajectories of physical activity, and binary logistic regression was performed to identify pre-retirement factors influencing changes in physical activity. Results Our findings indicate that retirement can lead to a decline in physical activity among older Chinese residents (OR = 0.85, 95%CI 0.75 similar to 0.97). We identified three distinct trajectories of physical activity during the retirement transition: Trajectory 1 - "sustained low level of physical activity" (7.94%); Trajectory 2 - "middle level of physical activity with gradual decline" (69.16%); Trajectory 3 - "sustained high level of physical activity with significant fluctuations" (22.90%). Furthermore, we discovered that individuals in the "middle level of physical activity and gradual decline" trajectory were more likely to have an annual income exceeding 40,000 yuan (OR = 9.69, 95%CI 1.12 similar to 83.63), reside in urban areas (OR = 2.27, 95%CI 1.14 similar to 4.52), and have a fondness for playing Mahjong (OR = 2.42, 95%CI 1.18 similar to 5.00) compared to those in the "sustained high level of physical activity with significant fluctuations" trajectory. Additionally, having an annual income exceeding 40,000 yuan (OR = 19.67, 95%CI 1.30 similar to 298.61) predicted membership in the "sustained low level of physical activity" trajectory when compared to the "sustained high level of physical activity with significant fluctuations" trajectory. Conclusion Retirement represents a substantial milestone in the life course and is associated with notable alterations in physical activity patterns. Among older Chinese residents, the trajectories of physical activity during the retirement transition exhibit diverse paths and are influenced by pre-retirement factors, including annual income, residential location, and hobbies. The findings of this study have important implications for the formulation of policies aimed at promoting healthy aging among individuals approaching retirement age.