Assessing the robustness of muscle strength and physical performance measures in women older than 40 years: a test-retest reliability study.

OBJECTIVES: This study investigated the test-retest reliability and minimal detectable change (MDC) of muscle strength and physical performance tests in women older than 40 years. METHODS: A total of 113 women, aged 58 ± 11 years (82% postmenopausal women), with a body mass index of 28.5 ± 5.8 kg/m 2 , participated in this study. One-repetition maximum (1RM) tests were conducted for seven strength exercises: 45° leg press, bench press, leg extension, pec deck, wide-grip lateral pull-down, leg curl, and seated cable row, with a retest after 48 hours. Timed Up and Go (TUG), 6-minute walk, and 30-second sit-to-stand tests were performed on the same day and retested after 72 hours. The tests and retests were administered by the same evaluators. Relative reliability (consistency of participant rank between test-retest) was assessed using the intraclass correlation coefficient for consistency and agreement, and absolute reliability (precision of score) was assessed using the MDC based on the standard error of prediction. RESULTS: The 1RM and performance tests exhibited excellent reliability: 45° leg press (consistency, 0.99; agreement, 0.98), bench press (consistency, 0.96; agreement, 0.96), leg extension (consistency, 0.93; agreement, 0.91), pec deck (consistency, 0.90; agreement, 0.88), wide-grip lateral pull-down (consistency, 0.91; agreement, 0.89), leg curl (consistency, 0.84; agreement, 0.83), seated cable row (consistency, 0.92; agreement, 0.94), TUG (consistency, 0.87; agreement, 0.87), 6-minute walk (consistency, 0.96; agreement, 0.95), and 30-second sit to stand (consistency, 0.85; agreement, 0.80). These tests showed meaningful MDC values, particularly for the 1RM test performed on the machine and the 30-second sit-to-stand test: 45° leg press, 22.2 kg (15%); bench press, 4.9 kg (19%); leg extension, 9.2 kg (35%); pec deck, 8.8 kg (44%); wide-grip lateral pull-down, 9.4 kg (31%); leg curl, 9.2 kg (51%); seated cable row, 11.4 kg (29%); TUG, 1.4 seconds (20%); 6-minute walk, 50.9 m (10%); and 30-second sit to stand, 4.6 reps (30%). CONCLUSIONS: Although the muscle strength and physical performance tests demonstrate excellent relative reliability in women older than 40 years, they exhibit low absolute reliability, particularly the 1RM test performed on the machine and the 30-second sit-to-stand test. Therefore, although these tests show good consistency in the positioning of women within the group after repeated measures, their precision measure is relatively low (high fluctuation). Changes in these tests that are smaller than the MDC may not indicate real changes in women at middle age and older.

The relationship between depressive symptoms and physical performance in postmenopausal women: a cross-sectional investigation.

OBJECTIVE: The relationship between depressive symptoms and declining physical performance in postmenopausal women has been extensively examined. However, various confounding factors can influence this association. This study aimed to investigate the link between depressive symptoms and physical performance in postmenopausal women while considering potential interfering factors. METHODS: In this cross-sectional study, 137 postmenopausal women were categorized into two groups based on the presence of depressive symptoms (n = 58; mean ± SD age, 60.12 ± 8.45 y) and absence of depressive symptoms (n = 79; mean ± SD age, 60.72 ± 7.45) using the Geriatric Depression Scale (short version) (GDS-15). Thoracic kyphosis angle was measured using the flexicurve method. Physical performance was assessed through various tests, including Timed Up and Go, Five Times Stand and Sit Test, 6-minute Walking Speed, 10-meter Usual Walking Speed, 10-meter Fast Walking Speed, and dynamometry. The study compared variables between the two groups and used linear regression models adjusted for dynamometry, kyphosis angle, age, antidepressant usage, sitting time, and fall history to evaluate the relationship between GDS-15 scores and physical performance. RESULTS: Significant differences were observed in physical performance, body mass index, kyphosis angle, antidepressant usage, sitting time, and fall history between women with and without depressive symptoms. The GDS-15 showed a negative association with all walking speed tests (10-meter Usual Walking Speed, m/s; P < 0.001; B = -0.01; 10-meter Fast Walking Speed, m/s; P < 0.001; B = -0.02; 6-minute Walking Speed, m/s; P < 0.004; B = -0.01) and a positive association with the Five Times Stand and Sit Test ( P < 0.002; B = 0.21) and Timed Up and Go ( P < 0.001; B = 0.13) tests, regardless of grip strength, kyphosis angle, age, antidepressant use, sitting time, or fall history in postmenopausal women. CONCLUSIONS: This study underscores the independent and substantial impact of depressive symptoms on the physical performance of postmenopausal women. These findings emphasize the importance of addressing both mental health and physical well-being when providing care and support for this demographic.