In Japan, the first country to experience a super-aging society, the development of independent rehabilitative care for older individuals in depopulated rural areas is an indispensable challenge to decrease a high incidence of weak psychosomatic state to need care. Interestingly, some studies provide evidence that dual-task training has been shown to induce improvements in targeted motor and cognitive function (Suzuki et al., Reference Suzuki2013; Tait et al., Reference Tait, Duckham, Milte, Main and Daly2017). However, these findings remain for older individuals leaving in relatively urban neighborhoods. This preliminary study examined the effect of dual-task training for Japanese older persons in depopulated rural areas.

This research was conducted from 2016 to 2019, including the Katagami’s study, and our previous studies at Oga and Higashinaruse areas (Kume et al., Reference Kume2017, Reference Kume2019). Thirty-five participants (age [mean±SD] 72.0±5.4 years; education, 11.4±2.3 years; %female, 94%) without a history of neurological, psychiatric disorders, and dementia were recruited from rural areas in Akita prefecture. The participants performed a 90-minute exercise program comprised of stretching, muscle strength training, a step-up/down aerobic exercise using the stepstool, and dual-task training (e.g. the step-up/down movement while working naming tasks, a colorful ladder exercise combined the Stroop task) for once per one or two weeks for six months (Suzuki et al., Reference Suzuki2013). Physical and cognitive measurements were performed at baseline and after the six-month intervention. The physical measurement consisted of the Timed Up and Go test (TUG), grip strength (GS), and the Sit to Stand-5 (SS-5). The National Center for Geriatrics and Gerontology Functional Assessment Tool (Shimada et al., Reference Shimada, Makizako, Park, Doi and Lee2017) was also applied to examine the effect to cognitive function before and after the intervention, comprised of the Word Recognition Memory (WRM) and the tablet version of the Trail Making Test – part A and part B (TMT-A, TMT-B). This study was approved by the Ethics Committee of Akita University (No. 1769).

The result of the Wilcoxon signed-rank test indicated that a required time (second) of the SS-5 was significantly shorter (median [interquartile range], pre-test = 6.7 [1.8], post-test = 5.4 [1.6], p < 0.0001), and the WRM score was significantly improved (pre = 12.0 [5.0], post = 13.0 [4.6], p = 0.008) after the intervention. However, a significant difference between pre- and post-tests was not observed in other physical and cognitive domains, such as the TUG (p = 0.44), the GS (p = 0.63), the TMT-A (p = 0.83) and TMT-B (p = 0.72).

Our preliminary findings lead us to believe that a dual-task exercise program can be potentially effective to the enhancement of motor and memory function for Japanese older persons in depopulated rural districts, in accordance with an improvement of memory scores following dual-task training (Suzuki et al., Reference Suzuki2013; Tait et al., Reference Tait, Duckham, Milte, Main and Daly2017). Whether these results generalize to enhancements for subjects in other areas remains unclear but warrants examination involving a randomized controlled trial.