We examined the relationship between the timing of habitual physical activities and sleep quality in older adults. The subjects were Japanese community-dwelling older adults (n=49, average age 70.1±3.5 years; men: 36.7%). We measured habitual physical activity using a 3-axis accelerometer (HJA-350 IT, Omron) for a week. Timing of physical activity was classified into the following three periods: (1) morning: waking to 11:59, (2) afternoon: 12:00 to 17:59, and (3) night: 18:00 to bedtime. We also categorized the intensity of habitual physical activity during 2 sessions as either (1) low (1.6-2.9 METs) or (2) moderate-to-vigorous (≧3.0 METs) intensity. The subjective sleep parameters were assessed using the Pittsburgh Sleep Quality Index (PSQI). We used a forced-entry multiple regression analysis to investigate the relationships between subjective sleep parameters and the timing of physical activities. Forced-entry multiple regression analysis revealed that sleep latency and PSQI global score were positively correlated with low-intensity physical activity at night. However, there was no significant correlation with moderate-to-vigorous activity. These results suggest that low-intensity habitual physical activity at night would be one useful and modifiable factor to improve sleep quality in the elderly.

Hemodialysis patients need to acquire exercise habits because physical inactivity in hemodialysis patients is associated with increased mortality. However, factors associated with exercise habits in hemodialysis patients are unknown. The purpose of this study was to investigate the factors related to exercise habits in hemodialysis patients. We measured 104 hemodialysis patients' exercise habits (transtheoretical model：TTM), laboratory data, self-efficacy (SE), short physical performance battery and grip strength, nutritional index, dialysis vintage, fluid removal, and Kt/V. Multiple linear regression analysis was carried out to assess the association of the aforementioned factors with TTM. As a result, in multiple linear regression analysis, SE, age, and Kt/V were associated with TTM (R2＝0.34, p＜0.05). hemodialysis patients may require mental support, such as SE and adequate dialysis dose, to acquire exercise habits.

Increasing light-intensity physical activity (LPA) or moderate-to-vigorous physical activity (MVPA) and decreasing sedentary behavior (SB) are important to maintain cognitive function in older adults. However, there is a lack of studies examining the influence of replacing time spent in SB, LPA and MVPA on cognitive function. Therefore, this study applied an isotemporal substitution (IS) model approach to examine the associations of objectively measured SB, LPA, and MVPA on multiple cognitive functions in older adults. We analyzed data from 145 older persons (mean age, 75.1 ± 4.5 years; 61.4% women) in Kasama City, Japan. We assessed SB, LPA, and MVPA for seven consecutive days with a triaxial accelerometer. To evaluate the cognitive function, we used the Five-Cog test (character position referencing task, category cued recall task, clock drawing task, animal name listing task, and analogy task). The IS model of the multiple regression analysis was used to examine the effects of replacing time spent on one activity type with 30 minutes per day of SB, LPA, and MVPA on multiple cognitive functions, adjusting for age, gender, body mass index, education, smoking, sleep duration, history of stroke, medication for hypertension, dyslipidemia, and diabetes and accelerometer wear time. The results showed that reallocation from SB to LPA was significantly related to the category cued recall task score (B = 0.69, 95% confidence interval 0.07 - 1.31). In contrast, other reallocations were not associated with any cognitive tasks. The results suggest that substituting SB with LPA is positively associated with verbal episode memory among older Japanese adults.

Hemodialysis patients need to acquire exercise habits because physical inactivity in hemodialysis patients is associated with increased mortality. However, factors associated with exercise habits in hemodialysis patients are unknown. The purpose of this study was to investigate the factors related to exercise habits in hemodialysis patients. We measured 104 hemodialysis patients' exercise habits (transtheoretical model：TTM), laboratory data, self-efficacy (SE), short physical performance battery and grip strength, nutritional index, dialysis vintage, fluid removal, and Kt/V. Multiple linear regression analysis was carried out to assess the association of the aforementioned factors with TTM. As a result, in multiple linear regression analysis, SE, age, and Kt/V were associated with TTM (R2＝0.34, p＜0.05). hemodialysis patients may require mental support, such as SE and adequate dialysis dose, to acquire exercise habits.