Anthropometric Characteristics and Cardiorespiratory Capacity in Adults over 50 Years with Disabilities: Association and Differences According to Sex

(1) Background: The Sustainable Development Goals highlight the importance of ensuring healthy lives and promoting well-being for all. Within this framework, it is essential to improve health outcomes for people with disabilities and to continue generating scientific evidence in this field. This study aimed to (I) analyze differences in anthropometric characteristics and cardiorespiratory fitness among adults with disabilities, and (II) analyze the association between anthropometric characteristics and cardiorespiratory fitness in the total sample and by sex. (2) Methods: Fifty-three adults over 50 years of age with disabilities participated in this study. Anthropometric measurements and the 6 min walk test (6MWT) were conducted, recording physical-physiological and mechanical variables (using heart rate monitors and Stryd devices). (3) Results: Significant differences were observed between men and women with disabilities in height (p < 0.001, ES = −1.10), hip-to-chest ratio (p < 0.05, ES = 0.75), mean heart rate (p < 0.05, ES = 0.67), and absolute minimum power (p < 0.05, ES = 0.64) achieved during the 6MWT. A significant correlation was found between anthropometric characteristics and 6MWT performance across the entire sample (r = −0.29 to −0.67, p < 0.05). Among women, these characteristics were associated with distance covered (r = −0.35 to −0.42, p < 0.05), whereas in men, they were associated with relative power (r = −0.60 to −0.83, p < 0.05). (4) Conclusions: The findings suggest that, in this sample, anthropometric characteristics are associated with specific 6MWT performance variables, with patterns differing by sex.