Approximately 40%–65% of new fitness club (FC) members cancel their membership within 6 months. To prevent such cancellations, it is essential to identify members at high risk of doing so. This study developed a model to predict the probability of discontinuing FC membership among new members. We conducted a cohort study and enrolled participants from 17 FCs in Japan. We asked 5,421 individuals who became members from March 29, 2015 to April 5, 2016 to participate in the study; 2,934 completed the baseline survey, which was conducted when the participants became FC members. We followed up the participants until September 30, 2016. We excluded 883 participants with missing values and 69 participants under aged 18 years; thus, our analysis covered 1,982 individuals. We conducted the random survival forest to develop the prediction model. The mean follow-up period was 296.3 (standard deviation, 127.3) days; 488 participants (24.6%) cancelled their membership during the follow-up. The prediction model comprised 8 predictors: age; month of joining FC; years of education; being under medical follow-up; reasons for joining FC (health improvement, relaxation); and perceived benefits from exercise (maintaining good body weight, recognition of one’s ability by other). The discrimination and calibration were acceptable (C statistic: 0.692, continuous ranked probability score: 0.134). Our findings suggest that the prediction model could assess the valid probability for early FC cancellation among new members; however, a validation study will be needed.

    Clinical research is essential for the practice of evidence-based medicine. This study reports on our current practice of clinical research support in Mito Kyodo General Hospital and discusses future challenges. In April 2013, the University of Tsukuba hired a clinical research assistant to provide clinical research support in Mito Kyodo General Hospital. The clinical research assistant worked full-time in the hospital in collaboration with 3 university faculty members. The target population for this study comprised 450 medical personnel including doctors, nurses, and other medical staff. From April 2014, 1 of the 3 faculty members visited the hospital once a month to offer clinical research consultations and deliver a lecture on nursing research. We analyzed past records of clinical research support and conducted a questionnaire survey to explore the level of satisfaction of the medical personnel. Four-hundred and ninety records of 91 research topics proposed by 68 medical personnel were identified. Of these, 93.4% were proposed by doctors or nurses. Most studies employed an observational study design (64.8%) and were conducted in order to make a presentation at an academic conference (51.1%). The consultation sessions were held 1–5 times, for 40–405 min, and lasted from 1–84 days per research topic. Consultations mostly pertained to research design and protocol planning (57.1%). Forty-seven clients were invited to participate in the questionnaire survey, 30 of whom provided valid responses. The results showed that 96.6% of the clients were satisfied with the consultations. The number of clients who participated in the consultations comprised only 15.1% of the target population. These practice biases need to be addressed in future. However, nearly all respondents were satisfied with the consultations. These findings suggest that our clinical research support was beneficial to medical personnel.

Most people who go to fitness clubs or sports gyms for weight control, and many co-medicals and physicians believe that an increase in muscle mass and/or basal metabolic rate (BMR) is possible through a combination of regular exercise and optimal protein intake during weight loss. This seems a myth, and the reasons are discussed in this article. First, muscle mass is quite difficult to quantify. The limitations of body composition measurement should be well understood. Second, increasing muscle mass during weight loss is difficult. This might be attained through strict implementation of a protein-rich, low-carbohydrate diet; high-intensity resistance training; and aerobic exercise for a long duration. However, such a strict regimen is not feasible for most people. Finally, a 1-kg increase in muscle mass corresponds to an increase of only 13 kcal of BMR per day. Thus, an increase in muscle mass of 1 kg is difficult to achieve, while the gained BMR is approximately equivalent to a decrease of 13.5 kcal of BMR according to a 3-kg decrease of adipose tissue. Weight loss, unless through an extremely sophisticated weight control program, contributes to a decrease in BMR. However, it is an accomplished fact that women with significantly less muscle mass and lower BMR live longer than men with more muscle mass and higher BMR, regardless of ethnicity. Maintaining activities of daily living and daily activity function might be more essential.

This study aimed to evaluate dynamic balance capability, bathyesthesia, and the composite compensation of bathyesthesia and visual sense for dynamic balance assessed by use of force plates and to examine their correlation to age in a cross-sectorial manner. Participants of this study were 147 healthy people (55 men, 92 women). To evaluate dynamic balance capability, we evaluated the index of postural stability (IPS), which is the logarithmic value of the ratio of the area of stability limits to the area of postural sway, with participants standing on a hard surface with eyes opened. To measure bathyesthesia, we evaluated the modified index of postural stability (MIPS), i.e., the IPS with participants standing on a soft surface with eyes closed. As for the composite compensation index of bathyesthesia and visual sense for dynamic balance, we calculated the rubber IPS Romberg ratio (MIPS/IPS). The correlation coefficients (Spearman’s rho) of IPS, MIPS and MIPS/IPS to age were −0.666 (p < 0.001), −0.697 (p < 0.001) and −0.600 (p < 0.001), respectively. These results suggest that dynamic balance capability and bathyesthesia decline with advancing age, and the composite compensation of bathyesthesia and visual sense for dynamic balance strengthens with advancing age.

Several studies have shown that low cardiorespiratory fitness (CRF) or heavy alcohol consumption is risks of total or certain types of cancer death. However, the combined influence of CRF and drinking habits on total cancer mortality is not clear. The purpose of this study was to investigate the joint effect of CRF and drinking habits on total cancer mortality among Japanese men. We evaluated the CRF and drinking habits on risk of total cancer mortality in 8,760 Japanese men (age: 19-59 yr) who were given a submaximal exercise test, a medical examination test, and questionnaires on their health habits. CRF was measured using a cycle ergometer test, and the men were classified into two categories by CRF levels based on the reference value of CRF (R-CRF) in “Physical Activity Reference for Health Promotion 2013” (Under R-CRF and Over R-CRF). Also, the men were assigned to Non Drinking, Moderate Drinking, and Heavy Drinking categories. There were 178 cancer deaths during the 20-yr follow-up period. Relative risk and 95% confidence intervals for total cancer mortality were obtained using the Cox proportional hazards model while adjusting for age, body mass index, systolic blood pressure, and smoking habits. Using the Under R-CRF & Heavy Drinking group as reference, the relative risk and 95% confidence intervals were 0.37 (0.16–0.85) for the Over R-CRF & Non Drinking group. This result suggests that Japanese male with a high CRF and a low drinking habit have a lower risk of total cancer mortality.

The purpose of this study was to develop a simple and easy predictive model of leg, spine and whole body bone mineral density (BMD) from anthropometric, physical fitness, body composition and quantitative ultrasound (QUS) variables. Participants were 138 Japanese overweight and obese men (50.9 ± 9.6 yr, body mass index [BMI] 29.1 ± 2.6 kg/m²). We measured anthropometric variables (height, weight, BMI, chest, waist, hip, upper arm, thigh circumferences), physical fitness (grip strength, side steps, vertical jump, forced vital capacity), body composition (fat-free mass) and QUS. BMD was measured by dual energy X-ray absorptiometry. Multiple linear regression analyses showed that all predictive models for BMD were significant. As a result, the predictive model for leg BMD showed the highest model fitting. The Bland & Altman approaches demonstrated the (positive or negative) systematic error even though most plots were placed within ideal range. Predictive model from physical fitness, body composition and QUS would be useful for estimating whole body and regional BMD. Because these predictive models are likely to have some systemic errors, further research is needed to improve the predictive accuracy.

The purpose of this study was to investigate the interaction of habitual exercise and candidate gene polymorphisms related to bone on osteo sono-assessment index (OSI) by quantitative ultrasound (QUS) in middle-aged and elderly Japanese. Participants were classified into exercise group (E; n=172, 62.3 ± 7.7 yr) and sedentary group (S; n=65, 58.6 ± 9.2 yr). The OSI was measured with AOS-100. DNA was extracted from blood, and single nucleotide polymorphism in vitamin D receptor, estrogen receptor α, and transforming growth factor-βI were genotyped by TaqMan assay. Group E had significantly lower body weight and body mass index (BMI) than Group S. In men, although Group E was older than Group S, Group E had significantly higher OSI rather than Group S. There was no significant interaction between habitual exercise and each gene polymorphism on OSI. These results essentially remained unchanged even when analysis of covariance was applied after adjustment for age, body weight, and BMI. These results suggest habitual exercise and genetic factors have no interaction on OSI in middle-aged and elderly Japanese. Further investigations are needed to prove the interaction of other gene polymorphisms and exercise.

It has been reported that visceral fat (VF) is an independent predictor of the incidence for coronary heart disease, and is associated with its risk factors. The independent effects of exercise or dietary modification on VF remain to be fully elucidated, especially in obese middle-aged men. The purpose of this study was to investigate effects of exercise on VF compared to dietary modification. Thirty-five obese middle-aged men participated in this study. They consisted of exercise group (n=22, 51.4±11.6 yr, Group E) and diet group (n=13, 48.8±12.2 yr, Group D). Participants in Group E followed 90-min exercise sessions on a regular basis 3 days per week for 12 weeks. Participants in Group D attended weekly classes aimed at maintaining well-balanced 1,680 kcal/d diet for 12 weeks. Body weight decreased significantly in both groups (Group E : −2.9 kg, Group D : −5.4 kg). Visceral fat area (VFA) determined by computed tomography also decreased significantly (Group E : −32.0 cm², Group D : −39.4 cm²). An analysis of covariance adjusted by weight change revealed no significant group difference in VFA change. These results suggest that exercise-induced negative energy balance does not result in greater decrease in VFA as compared with dietary modification alone.

The aim of this study was to examine a weight reduction program and residual effects, through confirming the relationship between changes in the morphological and psychological indices including personality and self-efficacy (SE) of the participants. Twenty-five middle-aged women were divided into two groups based on type of weight reduction program intervention. Thirteen women participated in a 3-month diet-only weight reduction program (DO group, 53.3±7.4 yr), and 12 women took part in a 3-month diet and aerobic exercise program (DE group, 48.3±9.6 yr). After the programs, the compatibility score of personality in the DO group was negatively correlated to SE that is indicated as confidence in ability to maintain decreased body weight at 2, 3, and 4 years after the program (r=-0.69, -0.58, and -0.60). It can be seen that personality has an effect on the results of the DO group weight reduction program. Additionally, despite a significant decrease in body-weight and %fat in both groups, only the change of %fat significantly correlated with SE. On the basis of these correlations, the changes of %fat that related to the movability perception of body movements has a greater effect on SE after the program than the information only of weight loss. The results of this study suggest that personality and SE accounted for weight maintenance, and were associated with the results of the weight reduction program.