Skeletal muscle is a vital tissue not only for maintaining posture and body movements but also for energy metabolism in human body. Skeletal muscle is highly plastic in response to various stimuli, resistance exercise or anabolic hormones can increase muscle mass, which is termed “muscle hypertrophy”. Contrary, immobility, aging and severe illness can reduce muscle mass, which is termed “muscle atrophy”. Loss of skeletal muscle mass is associated with loss of independent living, the morbidity of a variety of diseases and mortality throughout life. Therefore, understanding mechanisms that regulate skeletal muscle mass is essential for improving the quality of life. Recent studies reported microRNAs (miRNAs), which is a class of non-coding RNAs, play a crucial role in the regulation of muscle mass. This review provides a current understanding of the function of miRNAs in regulation of skeletal muscle mass.

It has been reported that using of the spine mat increases chest expansion, inspiratory capacity (IC) and maximum inspiratory mouth pressure (PImax). However, no changes were observed in other respiratory functions and the respiratory muscle strength. The purpose of this study was to clarify the effects of pursed-lip breathing lying on the spine mat to the respiratory function and respiratory muscle strength. Forty-two adult male participants were assigned to two groups; an intervention group (IG group) of 21 participants who performed pursed-lip breathing on top of a spine mat and a control group (CG group) of 21 participants who performed pursed-lip breathing only. The intervention period was 5 days, and the respiratory features evaluated were chest expansion, respiratory function, respiratory muscle strength, and spinal alignment. A significant increase between the Pretest and the Posttest in chest expansion at the circumference of the axilla level, of the xiphoid process level and of the 10^th rib level was observed only in IG group. For the respiratory function and the respiratory muscle strength, intervention group showed significant increases in percentage of vital capacity (%VC), tidal volume (TV), PImax, and maximum expiratory mouth pressure (PEmax). In the control group, only the TV indicated a significant increase. Regarding changes before and after the intervention, the intervention group showed significantly higher PImax and PEmax than the control group. No significant difference in spinal alignment was observed between the two groups. These results showed that pursed-lip breathing lying on the spine mat would increase the PImax, PEmax and the chest expansion.

Insufficient physical function is strongly associated with decreased activity of daily living and health-related quality of life in middle-aged and older women. YOSAKOI Soran is one of the traditional Japanese dances to have naruko (wooden hand clappers) in their hands as they dance and incorporate the phrase from the Soran Bushi in their song. YOSAKOI Soran festivals can be seen being held in various places across the country, proving its growing popularity with residents as a celebration regardless of age or occupation. The purpose of this study was to examine the cross-sectional associations between YOSAKOI Soran and the physical functions of middle-aged and older women. A total of 30 middle-aged and older women practicing YOSAKOI Soran (YOSAKOI group) and 163 middle-aged and older women who had not practiced YOSAKOI Soran (control group) participated in this cross-sectional study. Handgrip strength, 30-second chair stand performance, and flexibility were used to measure physical functions. Handgrip strength was not significantly differed between the YOSAKOI group and the control group (P = 0.79). 30-second chair stand performance and flexibility were significantly higher in the YOSAKOI group than in the control group (both P < 0.05). These results remained significant after adjusting for age and body mass index (both P < 0.05). The present results suggest that practicing YOSAKOI Soran may increase lower extremity function and flexibility in middle-aged and older women.