This study aimed to examine the effects of an 8-week physical activity program, which mainly comprised home-based bench-stepping exercise training at the intensity of lactate threshold (LT), on mental health (MH), health-related quality of life (HRQOL), and physical fitness in Japanese returnees from China. Thirty Japanese returnees (63 ± 9 y) participated in the exercise program. Another six subjects were enrolled as the control group. The subjects performed 212 ± 57 min of training, and their daily step counts were increased. Aerobic capacity (LT: 4.5 ± 0.8 vs. 5.5 ± 1.1 METs), lower limb strength (30-s chair stand test [CS-30]: 19.1 ± 5.5 vs. 21.3 ± 5.1 times), and sit-and-reach flexibility (sitting-posture body anteflexion: 36.1 ± 9.4 vs. 39.0 ± 8.4 cm) were significantly increased after the intervention compared with before the intervention. Furthermore, MH, as assessed by the total score of the GHQ-28 (3.4 ± 4.4 vs. 0.3 ± 0.8 points), and the mental component score (MCS) of HRQOL, as evaluated by the SF-36v2 (55.1 ± 11.4 vs. 58.5 ± 10.0), were significantly changed in a positive manner. However, a two-way repeated measures ANOVA (group × period) showed significant interactions for LT and MCS (p<0.05), and a tendency for interactions of CS-30 (p=0.063) and the total score of the GHQ-28 (p=0.098). These results indicate that this bench-stepping exercise program could become a useful health support program for improving physical fitness, as well as MH and HRQOL, in Japanese returnees.

Objectives: Few studies examined the association between deterioration of masticatory ability assessed by objective marker and physical function. Therefore, we examined the association between salivary flow rate which is one of the objective and surrogate marker of masticatory ability and lower Timed Up & Go (TUG) performance which is one of major measurement of physical function among aging Japanese. Methods: This cross-sectional study enrolled 464 Japanese aged 60e84 years old. Participants chewed tasteless and odorless gum for 5 min, calculated stimulated salivary flow rate (g/min) during all chews.The 3 m TUG was conducted, and 75th percentile value (6.8 s for men and 7.0 s for women) or higher was defined as lower TUG performance. Logistic regression analysis was used to examine the association between stimulated salivary flow rate and lower TUG performance. Results: We found that the stimulated salivary flow rate tended to be negatively associated with the TUG time. We also observed significant negative association between stimulated salivary flow rate and lower TUG performance; the multivariable-adjusted OR (95% confidence interval, CIs) of lower TUG performance for the highest quartile of stimulated salivary flow rate compared with the lowest quartile was0.34 (0.16e0.69, P for trend ¼ 0.02). Further adjusting for BMI, the association was attenuated but remaind significant; the OR (95% CIs) in highest quartile was 0.37 (0.18e0.76, P for trend ¼ 0.04). Conclusions Higher stimulated salivary flow, which means well masticatory ability, was inversely associated with lower TUG performance in the aging Japanese population.