Face-to-Face Exercises Performed by Instructors to Improve the Mental Health of Japanese in the Community—A Randomized Control Trial

Background and objectives: The purpose of this study is to clarify the effects on the mental health of face-to-face exercise performed by an instructor (lesson-style Group: Group L) and exercise using machines (program-style Group: Group P) by randomized control trial. Materials and Methods: Among 120 subjects, 117 subjects were allocated to two groups with stratified randomization by sex (Group P: 58 subjects; Group L: 59 subjects). A 60-min health exercise class was held once per week for 12 consecutive weeks. The measurement items were mental health as a primary evaluation item and self-efficacy as a secondary evaluation item. Physical fitness was also measured using a new physical fitness test used in Japan. The 12-item general health questionnaire (GHQ-12) was used to measure mental health and the general self-efficacy scale (GSES) was used to measure self-efficacy. Results: After the intervention, 102 subjects were analyzed. The changes in mental health evaluated by GHQ-12 scores were significantly lower in Group L −0.7 (95% CI, −1.2 to −0.3) than Group P −0.1 (95% CI, −0.4 to 0.2) (p = 0.03). The changes in self-efficacy evaluated by GSES scores were significantly higher in Group P 5.3 (95% CI, 3.1 to 7.5) than Group L 1.3 (95% CI, −0.4 to 3.1) (p < 0.01). Conclusions: Compared with program exercises mainly using machines, face-to-face exercises performed by instructors improved mental health.