Effect of Tai Chi vs. Strength Training on Body Composition, Physical Performance, and Well-Being in Community-Dwelling Older Mexican Women

<b>Background/Objectives</b>: Tai Chi (TC) practice has been shown to positively affect the physical, psychological, and cognitive health of older adults. However, discrepancies persist regarding its effectiveness compared to strength training (ST). This study aimed to determine the effect of TC training compared to ST on body composition, physical performance, cognitive function, and psychological well-being in older adults. <b>Methods:</b> A quasi-experimental study was conducted with a convenience sample of 68 women 60 years or older, divided into three groups: (i) Tai Chi Group (TCG) n = 26; (ii) Strength Training Group (STG) n = 21; and (iii) Control Group (CG) n = 21. TCG and STG performed physical training four days a week, 60 min/day, for six months. All participants were assessed for body composition (BFP, body fat percentage; SMM, skeletal muscle mass; SMMI, skeletal muscle mass index); physical performance (4MWT, 4 m walk test; STST, sit-to-stand test; OPP, overall physical performance; HGS, handgrip strength) and Wellbeing (PWBS, psychological well-being scale of Ryff, validated for the Mexican population). The data were analyzed per protocol using repeated-measures ANOVA (TCG & STG vs. CG; TCG vs. STG), and the mean difference (MD) was calculated. <b>Results:</b> TCG showed statistically significant changes in body composition, BFP (MD, -3.4 ± 8.2, <i>p</i> < 0.05), SMM (MD, 1.6 ± 1.4, <i>p</i> < 0.001), and SMMI (MD, 0.72 ± 0.61, <i>p</i> < 0.001) after the intervention compared to CG. However, no differences were observed between TCG and STG (<i>p</i> > 0.05). Regarding physical performance, TCG showed significant changes in 4MWT (MD, -1.0 ± 1.8, <i>p</i> < 0.01) and STST (MD, -3.7 ± 4.8, <i>p</i> < 0.05) compared to CG. Differences were also observed in STST between TCG and STG (MD, -3.7 ± 4.8 vs. 0.45 ± 3, <i>p</i> < 0.05). In addition, TCG showed a significant increase in HGS (MD, 1.1 ± 1.9, <i>p</i> < 0.05) compared to CG, although no differences were observed with STG (<i>p</i> > 0.05). <b>Conclusions:</b> Our findings suggest that TC is more effective than strength training for improving body composition, physical performance, and handgrip strength in older adults living in the community.