Active breaks (AB), short exercise sessions during class, have been shown to improve students' academic performance and concentration. To support AB implementation in elementary schools, we developed a questionnaire assessing teachers' knowledge, attitude, and confidence (KAC) regarding AB. The 43-item AB-KAC questionnaire was completed by 134 Japanese teachers and demonstrated strong construct validity (KMO: attitude = 0.857, confidence = 0.908) and internal consistency (Spearman-Brown = 0.86 for knowledge; Cronbach's alpha >= 0.80 for attitude and confidence). Factor analysis identified two attitude factors ("Positive AB beliefs" and "Negative AB beliefs") and two confidence factors ("Confidence in teaching AB" and "Confidence in creating materials and explaining AB"). KAC scores were significantly interrelated but not associated with years of teaching experience. The AB-KAC evaluates the promoting and inhibiting aspects of teachers' perspectives on AB regardless of their professional background. The initial analyses suggested reliability and construct validity, but further validation is required.

Few studies have shown that relatively younger children and adolescents (those born later in the same school year) were less likely to engage in physical activity in a phenomenon termed the relative age effect. Although these studies mainly targeted elementary and middle school students, no study has reported on the relative age effect on physical activity in ordinary high school students. Moreover, the relative age effect on sedentary behavior might show an opposite association with physical activity. Therefore, we aimed to clarify the relative age effects on physical activity and sedentary behavior across different school stages in Japanese children and adolescents. A cross-sectional questionnaire survey was conducted with 21,491 children and adolescents (elementary, middle, and high school students aged 10–18 years) in various Japanese regions from January 2018 to July 2019. Overall, 18,281 children and adolescents (10,299 boys and 7,982 girls) were finally included in our analysis. Data on the birth month, frequency and duration of their physical activity (vigorous, moderate, and moderate-to-vigorous intensity), and sedentary behavior (weekday and weekend total sedentary time, television viewing, playing video games, and Internet use) were obtained. We utilized two-part model regression analyses. Statistically significant association with birth month indicated that a relative age effect was observed. The relatively younger individuals were less likely to engage in physical activity (especially vigorous physical activity (VPA)); this association was observed in middle and high school students. Conversely, the relatively younger boys spent more time during weekends with sedentary behaviors and Internet use. Based on school stage, the relative age effect on VPA time was observed in middle school boys (average margin effect (AME) = -0.74, p < 0.01) and high school students (boys: AME = -0.69, p < 0.01; girls: AME = -0.53, p < 0.05). The relative age effect on sedentary behavior was observed during weekends with sedentary behaviors (AME = 3.55, p < 0.01), playing video games (AME = 0.72, p < 0.05) and Internet use (AME = 2.46, p < 0.01) for male high school students and on television viewing (AME = 1.12, p < 0.05) for female middle school students. The relative age effect on physical activity can persist after middle school, and the relatively younger individuals are more likely to replace physical activity with sedentary behavior.

Abstract Background Relative age effect is defined as a phenomenon where children born early generally perform better than children born later in the same cohort. Physical activity is an important factor that might be influenced by the relative age effect. Socioeconomic factors (e.g., parent’s income, education level) are also associated with the adolescent’s physical activity. However, no existing study has examined whether socioeconomic factors moderate the relative age effect on the adolescent’s physical activity. This study aims to clarify whether and how birth month and socioeconomic factors relate to organized sports and physical activity among adolescents in Japan. Methods We conducted a questionnaire survey targeting 21,491 adolescents who live in a widespread neighborhood. We included 8102 adolescents (4087 males and 4015 females: mean age 13.1 ± 1.4) in the analysis. Based on the participants’ birth months, we divided them into four groups (April to June, July to September, October to December, January to March). We asked participants to report their organized sports participation. Using the International Physical Activity Questionnaire for Japanese Early Adolescents, we identified their moderate to vigorous physical activity (MVPA). Neighborhood-level socioeconomic factors (areal deprivation, average annual income, education level) were analyzed based on national surveys, such as the population census. We performed multilevel logistic and linear regression analysis for organized sports participation and MVPA, respectively. Moreover, a simple slope analysis was implemented if the interaction between birth month and socioeconomic factor was significant in the multilevel linear regression analysis. Results Among males, relatively younger adolescents (adolescents who were born later in the same grade) were less likely to participate in organized sports activites (OR=0.90, 95% CI 0.82–0.97, p<0.05), while both males and females engaged in less MVPA (b=-0.54, b=-0.25, p< 0.01, respectively). We observed an interaction between birth month and socioeconomic factors. Among males in low-income neighborhoods, and females in more deprived neighborhoods, relatively younger adolescents engaged in less MVPA. Conclusions Socioeconomic factors moderate the relative age effect on adolescents’ physical activity. The relative age effect on adolescents’ physical activity might be more likely to appear among adolescents from socioeconomically disadvantaged neighborhoods.

In the last few years, esports have become popular among older individuals. Although participation in esports can become a novel activity for older adults, evidence on their effects is limited to young individuals. This study investigated the effects of esports participation on the emotional and physiological states of older adults. Twenty-five older men and women participating in health promotion activities in community centers (75 ± 8 years old) played a two-player racing game (Gran Turismo Sport, Sony) for 8–10 min. Their heart rates (HRs) were measured while the subjects played the games. The blood pressure (BP) and Profile of Mood States (POMS) were measured before and after gaming. The average HR during games (98 ± 17 bpm) was significantly higher than at pre-gaming (76 ± 11 bpm, p < 0.001). The BP before and after the games did not significantly change. Interestingly, the vigor scores (positive mood affect) in POMS increased after the games (p < 0.05) in females, but not in males. In summary, among older individuals, playing esports games showed a moderate increase in HR, no spike/drop of BP, and positive mood elevation. Our preliminary data suggest the feasibility of participating in esports in a community for older adults and that it could affect mood positively, especially among older women.

Abstract Background: Relative age effect is defined as a phenomenon where children born early generally perform better than children born later in the same cohort. Physical activity is an important factor that mitigates the relative age effect. Socioeconomic factors (e.g., parent’s income, education level) are also associated with the adolescent’s physical activity. However, no existing study has examined whether socioeconomic factors moderate the relative age effect on the adolescent’s physical activity. This study aims to clarify how birth month and socioeconomic factors moderate sports and physical activity among adolescents in Japan.Methods: We conducted a questionnaire survey targeting 21491 adolescents who live in a widespread neighborhood. We included 7138 adolescents (3701 males and 3437 females: mean age 13.06±1.44) in the analysis. Based on the participants’ birth month, we divided them into four groups (April-June, July-September, October-December, January-March). We asked participants to report their organized sports participation. Using the International Physical Activity Questionnaire for Japanese Early Adolescents, we identified their levels of sports activity and moderate to vigorous physical activity (MVPA). Neighborhood-level socioeconomic factors (areal deprivation, average annual income, education level) were analyzed based on national surveys, such as the population census. We performed multilevel logistic and linear regression analysis for organized sports participation and MVPA, respectively. Moreover, a simple slope analysis was implemented if the interaction between birth month and socioeconomic factor was significant in the multilevel linear regression analysis.Results: Among relatively younger adolescents (adolescents who were born later in the same grade), females were less likely to participate in organized sports activities (OR=0.91, 95% CI 0.85-0.98, p<0.01), while both males and females engaged in less MVPA (b=-4.08, b=-2.50, p<0.01, respectively). We observed an interaction between birth month and socioeconomic factors. Only low-income participants, females from more deprived neighborhoods, and relatively younger adolescents engaged in less MVPA. Conclusions: Socioeconomic factors moderate the relative age effect on adolescents’ physical activity. The relative age effect on adolescents’ physical activity might be more likely to appear among adolescents from socioeconomically disadvantaged neighborhoods.

Objective: This study examined the relationship between neighborhood food and physical activity environment, and obesity among elementary and junior high school students in Japan. Methods: The participants were fifth- to ninth-grade children (n=7277), who were attending municipal schools in Japan. Percent overweight (POW) was calculated using their age, gender, height, and weight, which were collected through a questionnaire. A POW of < 20% was considered non-obese, while ≥ 20% was considered obese. Furthermore, using a geographic information system, we investigated the density of convenience stores, fast-food stores, casual restaurants, supermarkets and department stores, parks, sports facilities, stations, and intersections in the school district. Additionally, from the census, we obtained information regarding the population density of the municipality where the participants’ schools were located. Multiple logistic regression analysis was used to examine the relationship between obesity and food environment (the food environment model), between obesity and physical activity environment (the physical activity environment model), and among obesity, food, and physical activity environment (the food and physical activity environment model). Results: In the food environment model and the food and physical activity environment model, the density of convenience stores showed a significant positive association. In the physical activity environment model, the density of stations showed a significant negative association. Conclusion: This study’s findings can contribute to the development of appropriate community interventions for improving children’s health in Japan and similar areas.

The current focus of meeting the physical activity guidelines for children and young people include preventing conditions such as high blood cholesterol, high blood pressure, metabolic syndrome, obesity, low bone density, depression, and injuries. However, the relationship between sleep habits and meeting physical activity guidelines is still unclear. This study aimed to assess this relationship among fifth- to eighth-grade (ages 10–14) Japanese children. This cross-sectional study included 3,123 children (boys: 1,558, girls: 1,565, mean age: 12.5 ± 1.2 years). Questionnaires were used to assess parameters such as moderate-to-vigorous physical activity per day, school and weekend night sleep durations, social jetlag, daytime sleepiness, napping, screen time, and breakfast intake. Participants were divided into an achievement and a non-achievement group depending on their physical activity guideline achievement status (i.e., whether they met the children’s physical activity guideline of 60 min or more of moderate-to-vigorous physical activity per day). Then, to determine the sleep habits in relation to the children’s achievement of guideline-recommended physical activity levels, multivariate logistic regression analyses were conducted. In fifth- and sixth-grade (ages 10–12) boys, an inverse association was observed between physical activity guideline achievement and daytime sleepiness. In seventh- and eighth-grade (ages 12–14) boys, physical activity guideline achievement was inversely associated with social jetlag and skipping breakfast. Additionally, in seventh- and eighth-grade girls, physical activity guideline achievement was inversely associated with inappropriate sleep duration on weekends and screen time. These results suggest that meeting the physical activity guideline is related to favorable sleep habits in Japanese children. However, their relevance may differ by school type and gender.

The present study tested the hypothesis that resistance exercise training focusing on eccentric muscle contractions would improve muscle strength and functional physical fitness more than concentric contraction-focused resistance training in older adults.

The decrease of balance capacity is considered as a high risk factor of fall accident, so it is important for the middle-aged and elderly people to keep balance capacity on a high level. In this study, we investigated the effects of aqua exercise on dynamic and static balance function. Thirty-two middle-aged women (56.6 +/- 8.1 years) participated a 60-min aqua exercise program three times per week for eight weeks. After exercise intervention, body weight, body mass index, grip strength, side step, shuttle stamina walking test were significantly improved (p < 0.05-0.001). Functional reach (p < 0.001) and total length of centroid shake with eye close condition (p < 0.05) was significantly improved, but with eye open condition was not changed. However, when we evaluate the total length of centroid shake by T-score, static balance performance with eye open and close condition was significantly (p < 0.05) improved in the below average groups. In addition, measurement value of functional reach was also improved in these groups. These results indicate that aqua exercise benefits not only physical muscle strength and endurance capacity, but also balance function in middle-aged women. Particularly aqua exercise is more effective for the subjects with lower static balance function before intervention.

BACKGROUND:To decide the minimal levels (thresholds) of physical activities necessary for a self-supporting life using discriminate analysis between community-dwelling elderly individuals and daycare-service-receiving elderly individuals in Japan.METHOD:A total of twenty-six elderly women, including twelve living a self-supporting life and fourteen using a daycare service, were recruited in this study. The parameters examined were physical performance, activities of daily living, exercise capacity. Discriminate analysis was used to determine the thresholds of physical activities needed to live a self-supporting life.RESULTS:Muscle masses, grip strength, lower-extremity muscle force, gait ability and balance function in elderly individuals living a self-supporting life were significant higher than those in elderly individuals using a daycare service. A threshold of physical ability over 75% classifies accurately using the methods of discriminate analysis indicate total body muscle mass, thigh muscle mass, knee extension force, 6 min walking distance (6MD), 10 m obstacle walking time, Activity of daily living (ADL) index and daily steps.CONCLUSIONS:The present study indicates that thresholds of physical activities including gait abilities, muscle force, and muscle mass are very important factors in maintaining a self-supporting life for elderly individuals. Thresholds of physical activities were more effective than standard values of physical activity for elderly individuals using a care service in meeting the goals of rehabilitation.

In this study, we investigated the effect of low-frequency ES (electric stimulation) to muscle oxygenation level by NIRS (near infrared spectroscopy) from comparing with V-Ex (voluntary exercise). Ten subjects performed ES and V-Ex test in supine position on a bed with 90 degrees flexion of the right knee joint and fixation of the right ankle to the end of the bed with a strap. NIRS probe was placed on middle point of the vastus lateralis, and four electrodes were placed across the motor point of the rectus femoris and vastus lateralis. Stimulation voltage was started at 20 V (20 Hz, pulse duration: 200 micros, duty-cycle: 1s-1s), and then was increased at a rate of 3 V/30 s until maximal tolerance level. V-Ex (isometric knee extension) was performed with same posture as in ES, and exercise pattern was set at a 1-s contraction and 1-s relaxation cycle. Exercise intensity was started at 5% MVC (maximal voluntary contraction) and was increased at a rate of 5% MVC/30 sec until exhaustion. In ES and V-Ex, tissue oxygenation index was decreased with decrease in O2Hb (oxy-hemoglobin) and increase in HHb (deoxyhemoglobin), and muscle oxygenation levels at the end of test were very alike. Oxygen consumption, heart rate, systolic and diastolic blood pressure in ES and V-Ex increased significantly, however, the degree of change in ES was significantly lower than V-Ex. Blood lactate was significantly increased in both tests. Adrenaline and noradrenaline were significantly increased in V-Ex, even though they showed no change in ES. These results lead us to believe that ES is an effective technique activated muscle hypoxia and glycolytic pathway metabolism with low stress on respiratory, circulatory and sympathetic nervous systems.

We investigated the relationship between body weight reduction and intensity of daily physical activities assessed with 3-dimensional accelerometer during a 3-month exercise program. Twenty-six middle-aged women (58.1 +/- 7.4 yrs.) participated in this study. Participants underwent a 90-min endurance exercise intervention once a week, and a 3-dimensionsal accelerometer was attached through the program. Body weight (BW), body mass index, fat mass and percent body fat were reduced significantly (p < 0.001), while diastolic blood pressure (p < 0.01) and shuttle stamina walking test (p < 0.05) improved significantly after the exercise intervention. Moreover. a significant negative correlation was observed between the changes in BW and total activity time (TAT) per day of more than 3METs (TAT >= 3METs) (r=-0.580, p < 0.01) and TAT >= 4METs (r=-0.627, p < 0.001). To the contrary, the daily steps and the TAT >= 2METs were not related to the changes in BW. After adjusting daily steps, TAT >= 3METs (beta=-0.630, p < 0.01) and TAT >= 4METs (beta=-0.659, p < 0.01) were still significantly related to the changes in BW. These results indicate that weight reduction has a much closer relationship with exercise intensity than daily steps. It is important to keep both quantity and intensity of exercise in the unsupervised exercise program aimed at weight reduction.

Adipose tissue secrets various protein (adipocytokine) and secret disorder of adipocytokine strongly relate to many diseases. Physical exercise is recommended for prevention of a life-style related disease, but the relationship between adipocytokine and physical exercise is not well known. PURPOSE: To investigate the effect of endurance exercise for plasma adipocytokine levels in middle-aged obese women. Method: Seventeen middle-aged obese women subjects (53.6±8.7years, 70.4±8.0kg, body mass index 28.6±3.6, %fat 37.8±6.2%) were participated in this study. Experimental bout was 3 months. Subjects were underwent 1 day/w 90min/day exercise program with endurance exercise (aerobic dance, step exercise and ball exercise etc), and we advised to perform walking exercise as every day as possible. result: Average steps in subjects for 3 months was 8762±2963steps/day. Body weight, body mass index, percent body fat and diastolic blood pressure were significantly decreased, and shuttle stamina test (endurance performance) and stepping test (quickness performance) were significantly improved. Plasma PAI-1 levels (pre: 30.8±22.3ng/ml, post: 20.5±10.8ng/ml, p < 0.05) and homeostasis model assessment (HOMA-IR; pre: 1.9±1.1, post: 1.7±0.9, p < 0.05) were significantly decreased respectively. Moreover, delta PAI-1 was significantly correlated with delta percent body fat (r=0.504, p < 0.05). On the other hand, plasma adiponectin (pre: 10.9±2.6ug/ml, post: 10.0±3.2ug/ml) and leptin (pre: 14.3±6.6ng/ml, post: 17.2±6.6ng/ml) were not improved. CONCLUSION: The endurance exercise on Japanese middle-aged obese women improved insulin resistance without plasma adiponectin and leptin intervention, in addition it related to prevention of vascular disorders by increasing plasma PAI-1 levels.

Various near-infrared spectroscopy (NIRS) variables have been used to estimate muscle lactate threshold (LT), but no study has determined which common NIRS variable best reflects muscle estimated LT. Establishing the inflection point of 2 regression lines for deoxyhaemoglobin (DeltaHHb(i.p).), oxyhaemoglobin (DeltaO2Hb(i.p.)), and tissue oxygenation index (TOIi.p.), as well as for blood lactate concentration, we then investigated the relationships between NIRS variables and ventilatory threshold (VT), LT, or maximal tissue hemoglobin index (nTHImax) during incremental cycling exercise. DeltaHHb(i.p.) and TOI(i.p.) could be determined for all 15 subjects, but DeltaO2Hb(i.p.) was determined for only 11 subjects. The mean absolute values for the 2 measurable slopes of the 2 continuous linear regression lines exhibited increased changes in 3 NIRS variables. The workload and VO2 at DeltaO2Hb(i.p.) and nTHImax were greater than those at VT, LT, DeltaHHb(i.p.), and TOI(i.p.). For workload and VO2, DeltaHHb(i.p.) was correlated with VT and LT, whereas DeltaO2Hb(i.p.) was correlated with nTHImax, and TOI(i.p.) with VT and nTHImax. These findings indicate that DeltaO2Hb strongly corresponds with local perfusion, and TOI corresponds with both local perfusion and deoxygenation, but that DeltaHHb can exactly determine deoxygenation changes and reflect O2 metabolic dynamics. The finding of strongest correlations between DeltaHHb and VT or LT indicates that DeltaHHb is the best variable for muscle LT estimation.

The purpose of this study was to examine the influence of muscle mass/power of the lower-extremities, including asymmetry in knee extension force, on gait ability of Japanese community-dwelling elderly women. The study population comprised 30 women aged 65-89 years. The parameters examined were activities of daily living, physical performance, functional capacity, isometric muscle forces of knee extension and flexion measured by a dynamometer, and muscle mass measured by bioelectrical impedance analysis. Asymmetry in knee extension force was calculated from rate of difference between the right and the left knee extension forces. One leg balance with eyes open, 6-minute walking distance (6MD) and knee extension force decreased, while 10-m obstacle walking time and asymmetry in knee extension force increased with age. Gait ability including 6MD and 10-m obstacle walking time correlated with asymmetry in knee extension force, which also exhibited correlations with one leg balance with eyes open and knee extension force. The results of the present study indicate that on increase in asymmetry in knee extension force as well as a decrease in lower-extremity muscle force might accelerate the loss of gait ability, while the improvement of asymmetry in knee extension force might be beneficial to self-supporting life in elderly individuals.

We assessed the major factors regulating adiponectin levels and the influence of exercise training on adiponectin levels in young obese men (19.2±1.1 yrs, BMI: 31.1±4.2, %fat: 27.2±3.9%). Subjects were separated into three groups (aerobic exercise group [AE: n=7], aerobic and resistance exercise group [AE+RE: n=7], control group [n=7]). AE underwent an 8-week training program (three times per week, more than 30 min endurance exercise at ventilatory threshold (VT) intensity). AE+RE went through resistance exercise two or three times per week together with the above endurance exercise for 5 months. Prior to intervention (n=21), adiponectin levels were significantly correlated with percentage of fat. Stepwise multiple regression analysis revealed that percent body fat was an independent predictor of basal adiponectin levels (r2=0.370; P<0.01). After intervention, fat mass, and VT were significantly improved in AE. AE+RE exhibited significant reduction in weight, BMI, percent body fat and fat mass, and had significantly increased VT, \(\ifmmode\expandafter\dot\else\expandafter\.\fi{V}{\text{O}}_{2} \max ,\) cycling power and torque. Insulin was not changed in both groups. The control group exhibited no significant change in any variables. Although adiponectin levels were unchanged in the three groups, a significant negative correlation between delta fat mass and delta adiponectin levels was observed (n=21, r=−0.461, P<0.05). In addition, delta percent body fat was an independent predictor of delta adiponectin levels (r2=0.327, P<0.05). These findings indicate that for increasing the adiponectin level, improvement of the body composition of young obese men is more important than the way training is performed.

The purpose of this study was to investigate the effect of constant endurance cycling exercise below Ventilatory Threshold (VT), under different pedal rate/torque regulations (PTR), on muscle oxygenation, as well as cardio-respiratory function and energy metabolism. Eight healthy male adults participated in the study for three tests. The first test was to examine the maximum oxygen uptake (V)over dot O(2)max) using a ramp loading measurement of 60 rpm, 20 watt/min ; and an individual 80% VT load was obtained. The second and third tests (random) were to measure heart I-ate (HR), blood pressure (MAP), expired gas and NIRS data before, during and after 30 min 80% VT constant cycling exercise with low pedal rate/high torque (LPHT : 32 rpm, 23.3 +/- 6.0 Nm) or high pedal rate/low torque (HPLT : 79rpm, 9.4 +/- 2.4 Nm). As a result, HPLT showed higher values in HR (p < 0.001), MAP (p < 0.001), (V)over dot O-2 (P < 0.001), (V) over dot CO2 (p < 0. 001) and RER (p < 0. 05), than LPHT : but LPHT showed a higher fat consumption rate than HPLT(p < 0.05). Significant PTR effect were recognized for the parameters of the tissue hemoglobin index (THI) (p < 0.001) and oxygenation hemoglobin (Delta O(2)Hb) (p < 0.01); and both indicated higher values for HPLT than LPHT; but LPHT showed insignificantly (p = 0.066) higher de-oxygenation hemoglobin (Delta HHb) than HPLT. Moreover, the significant time effects of THI and Delta O(2)Hb were also recognized. In conclusion, this study indicated that during constant cycling exercise below VT, HPLT might result in greater muscle blood volume, higher muscle oxygenation concentration and higher HR and (V) over dot O-2 compared with LPHT. These results suggest that, HPLT might be effective in alleviating the working load on lower limbs, as well as promoting muscle oxygenation, cardiorespiratory function (systemic oxygen supply) and energy metabolism. Therefore, HPLT constant cycling exercise below VT could be used in a rehabilitation program as a beneficial exercise for elderly people with decreasing muscle strength in their lower limbs.

Abrams, Jonathan Ahuja, R.K. Asano, Takao Asanoi, Hidetsugu Badimon, Juan J. Bove, Edward L. Brown, H.F. Carmeliet, Edward Caro, Colin G. Faxon, David P. Folkman, Jodah Francis, Gary S. Fujiwara, Keigi Goto, Yoichi Gross, Garrett J. Grover, Gary J. Hase, Hiroki Haze, Kazuo Hiejima, Kazumasa Higgins, Chales B. Hiramatsu, Kenji Hiraoka, Masakazu Huber, Sally Ann Ishide, Nobumasa Kasanuki, Hiroshi Kato, Masaaki Karmazyn, Morris Kawamura, Keishiro Kitakaze Masafumi Kobori, Shozo Kodama, Itsuo Kodama, Kazuhisa Koike, Akira Kyo, Shunei Ladoux, Annie Lewis, Malcom J. Makino, Keisuke Masuda, Yoshiaki Matsuda, Tetsuya McKay, Raymond G. Miyatake Kunio Momma, Kazuo Moore, E. Neil Morady, Fred Nakamura, Yasuyuki Nakano, Kiyoharu Nakazawa, Hiroe Nishida, Hiroshi Nishimura, Masao Nishimura, Yasuharu Nosé, Yukihiko Numano, Fujio Ohashi, Kyoichi Ohe Tohru Okano, Teruo Onouchi, Zenshiro O'Rourke, Michael F. Ozaki, Yukio Packer, Milton Parratt, James R. Pekiömäki, Juha S. Perloff, Joseph K. Peterson, Jon N. Przyklenk, Karin Richardson, P.J. Roach, Margot R. Rosano, Giuseppe M.C. Rubin, Kristofer Russo, Andrea M. Saji, Tsutomu Sakomura, Yasunari Saruta, Takao Sasaki, Tomio Schaft, Hartzell V. Senda, Shoichi Serruys, Patrick W. Shah, Ajay Sietsema, Kathy E. Simonsen, Ulf Singh, Bramah N. Standen, Nicholas B. Suita, Sachiyo Takahashi, Masato Takamiya, Makoto Takano, Tatsuya Takeo Satoshi Tamaki, Nagara Thomas, James D. Topaz, On Treasure, Charles B. Vacek, James L. Vanhoutte, Paul M. Vrolix, Matty C. Wizemann, V. Yamamoto, Kazuya Yokota, Mitsuhiro Yokoyama, Mitsuhiro Yutani, Chikao

2070 Adipose tissue is not merely energy storage organ, but is also endocrine tissue that secrets various proteins (adipocytokines). Plasma adiponectin, one of the adipocytokines, is reduced in middle-aged obesity, patients with type 2 diabetes and coronary artery disease. Exercise training was largely accepted to prevent these disorders. However, the relationship between adiponectin and exercise training has not been elucidated. PURPOSE: To investigate 1) the effects of early-aged obesity on plasma adiponectin levels and 2) the relationship between plasma adiponectin levels and endurance exercise training in young obese men. METHODS: Ex1) Twentysix male college students (19.2 ± 1.1 years, obese group: n = 15, 93.0 ± 13.8 kg, %fat 28.7 ± 3.3%, non-obese group: n = 11, 64.6 ± 5.0 kg, %fat 13.7 ± 3.5%) participated in this study. Ex2) Fourteen young obese men (19.4 ± 1.0 years, 94.7 ± 15.1 kg, %fat 31.4 ± 4.7% were divided into two groups (training group: n = 7, control group: n = 7). Training group underwent exercise with ergometer/treadmill at the levels of ventilatory threshold (VT) intensity for more than 30 min/day for 3days/week for 8weeks. RESULTS: Plasma adiponectin levels in the obese group were significantly lower than those in the nonobese group (obese: 4.7 ± 2.0micro-g/ml, non-obese: 6.8 ± 2.2micro-g/ml, p<0.05). Plasma adiponectin levels were significantly correlated with body weight (r = −0.415, p<0.05) and percent body fat (r = −0.412, p<0.05). Stepwise multiple regression analysis revealed that percent body fat was a significant independent predictor of plasma adiponectin level (r = 0.406, p<0.05). In our raining program, weight, BMI and %fat were not significantly decreased. VT was significantly improved in training group (from 13.5 ± 3.8 to 15.1 ± 3.4 ml/kg/min, p<0.05), but plasma adiponectin levels was not increased in both groups (training group: from 3.7 ± 2.2 to 4.0 ± 1.9micro-g/ml, control group: from 4.8 ± 2.0 to 4.9 ± 1.9micro-g/ml). CONCLUSIONS: Plasma adiponectin levels were already reduced in young obese male subjects, and were correlated with body fat. In addition, it was suggest that plasma adiponectin levels in these subjects were not altered by endurance exercise training without decreasing body fat, even if VT was improved.