Which Sit-to-Stand Test Best Differentiates Functional Capacity in Older People?

The sit-to-stand test provides insight into age-related functional capacity; however, there are various variants of sit-to-stand, and we do not know which of these better discriminates against age-related functional capacity. Our study aimed to compare the age-related functional capacity in older people by evaluating sit-to-stand power variants, using young individuals as a reference. A cross-sectional study was conducted in 102 adults (57 women) aged 60-80 and 105 adults (54 women) aged 20-30. Participants performed five times sit-to-stand (5 sit-to-stand), 30-second sit-to-stand, and 1-min sit-to-stand. Z scores were obtained for each sit-to-stand variant using power (W), relative (W/kg), and allometric (W/m 2 ) normalization methods. A mixed repeated-measures analysis of variance assessed the interactions among the sit-to-stand variants, normalization methods, sex, physical activity, and tobacco history. A significant interaction between sit-to-stand variants, normalization methods, and sex ( P = 0.002) was found. The mean effect of sit-to-stand variants revealed that the 1-min sit-to-stand had the lowest Z score ( P < 0.05). Significant variations were observed between sit-to-stand variants in all normalization methods for women ( P < 0.001). However, in men, only the difference between 5 sit-to-stand and 1-min sit-to-stand remained consistent across normalization methods ( P < 0.05). Our findings highlight the efficacy of 1-min sit-to-stand in distinguishing age-related functional capacity over the other sit-to-stand tests, especially in women.