Validity and reproducibility of an incremental sit-to-stand exercise test in healthy middle-aged individuals

[Purpose] We aimed to evaluate the validity and reproducibility of the incremental sit-to-stand exercise test for aerobic fitness evaluation in healthy middle-aged individuals. [Participants and Methods] Thirteen healthy middle-aged individuals randomly underwent the incremental sit-to-stand exercise and cycle ergometer tests, and the peak oxygen uptake was measured during both tests. Pearson's correlation coefficients were used to assess the strength of the association between the peak oxygen uptake measured during the aforementioned tests. Intraclass correlation coefficients with 95% confidence intervals for peak oxygen uptake obtained during the first, second, and third incremental sit-to-stand exercise tests were used to determine the reproducibility of this test. [Results] The peak oxygen uptake measured during the incremental sit-to-stand exercise test was strongly associated with that measured during the cycle ergometer test (r=0.86). The intraclass correlation coefficients (95% confidence intervals) used to verify the association of the peak oxygen uptake between the first and the second incremental sit-to-stand exercise tests and between the second and third incremental sit-to-stand exercise tests were 0.92 (0.66-0.99) and 0.96 (0.82-0.99), respectively. [Conclusion] The incremental sit-to-stand exercise test is a valid and reproducible tool to evaluate aerobic fitness in healthy middle-aged individuals.