Efeitos de um programa de 12 semanas de Tai Chi Chuan combinado com caminhada em parâmetros físicos e mentais de idosos: Um ensaio clínico randomizado

Abstract

Population aging is a global phenomenon that poses significant challenges to health systems and the quality of life of older adults. Several physiological and cognitive declines accompany this process, such as reductions in muscle strength and mass, functional capacity, and cognition, as well as increased prevalence of sleep disorders, depressive and anxiety symptoms. In this context, multicomponent physical exercise programs have been widely recommended to promote healthy aging. However, structural, economic, and logistical barriers often limit the large-scale implementation of complex programs, especially in public health settings. Tai Chi Chuan (TCC), a Chinese mind-body practice, has emerged as a viable, accessible, and potentially multicomponent alternative for promoting health among older adults. Muscle strength has been investigated in studies involving Tai Chi Chuan, but the evidence remains limited and inconclusive, particularly among healthy older adults, highlighting the need for more targeted research on this outcome. This doctoral thesis aimed to investigate the effects of a Tai Chi Chuan program combined with walking on physical and mental health parameters in older adults, and to assess the potential of TCC as a multicomponent exercise. The thesis is composed of three interrelated studies. The first is a narrative review of the literature examining the effects of TCC on variables related to muscle strength, balance, flexibility, and aerobic capacity in older adults. The review indicated that TCC may provide meaningful stimuli across these domains, although methodological limitations were observed, particularly concerning muscle strength and cardiorespiratory fitness. The second study presented the methodological design of a randomized, two-arm, parallel-group, 12-week clinical trial comparing a program of TCC combined with walking to a walking-only active control group. The protocol described eligibility criteria, intervention structure, primary outcomes (maximal strength of knee extensors and lower-limb functional performance), and secondary outcomes (localized muscle endurance, isometric strength, balance, muscle thickness and quality, cognition, quality of life, sleep, psychological symptoms, and clinicalfunctional vulnerability), along with the planned statistical analyses. The third study reported the results of the clinical trial. The results indicated the superiority of the intervention in improving knee extensor strength (Δ=+2.7kg; d=0.210) and the psychological domain of quality of life (Δ=+4.4 points; d=0.150). General improvements were also observed in functional, cognitive, and mental health aspects, with no differences between groups. It is concluded that the combination of Tai Chi Chuan and walking is an effective and feasible strategy to promote physical and mental health in older adults. The thesis contributes to the advancement of scientific evidence on integrative practices and may support future community-based interventions and public policies aimed at healthy aging.