Effects of Resistance Exercise and Essential Amino Acid Intake on Muscle Quality, Myokine, and Inflammation Factors in Young Adult Males.

BACKGROUND: Recently, many studies have been devoted to discovering nutrients for exercise-like effects. Resistance exercise and the intake of essential amino acids (EAAs) are known to be factors that can affect muscle mass and strength improvement. The purpose of this study was to investigate changes in muscle quality, myokines, and inflammation in response to resistance exercise and EAA supplementation. METHODS: Thirty-four males volunteered to participate in this study. They were assigned to four groups: (1) placebo (CO), (2) resistance exercise (RE), (3) EAA supplementation, and (4) RE + EAA supplementation. Body composition, muscle quality, myokines, and inflammation were measured at baseline and four weeks after treatment. RESULTS: Lean body fat had decreased in both RE and RE + EAA groups. Lean body mass had increased in only the RE + EAA group. In all groups except for CO, irisin, myostatin A, and TNF-α levels had decreased. The grip strength of the right hand and trunk flexion peak torque increased in the RE group. The grip strength of the left hand, trunk flexion peak torque, and knee flexion peak torque of the left leg were increased in RE + EAA. CONCLUSIONS: RE, EAA, and RE + EAA could effectively improve the muscle quality, myokine, and inflammation factors of young adult males. This finding highlights the importance of resistance exercise and amino acid intake.

Relationship between sleep quality and gravitational Tolerance.

BACKGROUND: The purpose of this study was to investigate the relationship between sleep quality and gravitational tolerance because sleep could directly affect physiological variables of the human body. METHODS: For the present study, 157 male Korea Air Force Academy cadets were recruited. They were assigned into a gravity (G)-tolerance test pass group (GP, n = 87) and a G-tolerance test fail group (GF, n = 70). All participants were assessed for G-tolerance test and Pittsburgh Sleep Quality Index (PSQI), a self-report questionnaire. Physical fitness test was performed based on the physical fitness test of the Ministry of National Defense of Korea. RESULTS: Independent t-test showed that PSQI global score (p < 0.001), PSQI sleep quality (p < 0.001), PSQI sleep onset latency (p = 0.009), PSQI sleep disturbance (p < 0.001), and PSQI daytime dysfunction (p < 0.001) were significantly different between the two groups. Participants with PSQI score less than 5 were more likely to have a longer G-tolerance test time (OR = 4.705, 95% CI = 2.00-11.05). Additionally, associations between those with PSQI score less than 5 (OR = 4.567, 95% CI = 1.94-10.74) were after adjusting (< 30 s and ≥ 30 s) for covariates. A negative correlation was found between G-tolerance test time and PSQI global score (p < 0.001). Negative correlations were found among 3 km running, push-up (p < 0.001), and sit-up (p < 0.001). A positive correlation was found between push-up and sit-up (p < 0.001). CONCLUSION: In conclusion, participants with good sleep quality were 4.705 times more likely to have longer G-tolerance test time. Thus, it is important for aircraft pilots to manage their sleep quality. Pre-pilots should also improve their sleep quality to pass the G-tolerance test.

Exercise therapy for sarcopenia and diabetes.

Aging is characterized by the gradual deterioration of function at the molecular, cellular, tissue, and organism levels in humans. The typical diseases caused by changes in body composition, as well as functional decline in the human body's organs due to aging include sarcopenia and metabolic disorders. The accumulation of dysfunctional aging ß cells with age can cause decreased glucose tolerance and diabetes. Muscle decline has a multifactorial origin, involving lifestyle habits, disease triggers, and age-dependent biological changes. The reduced function of ß cells in elderly people lowers insulin sensitivity, which affects protein synthesis and interferes with muscle synthesis. The functional decrease and aggravation of disease in elderly people with less regular exercise or physical activity causes imbalances in food intake and a continuous, vicious cycle. In contrast, resistance exercise increases the function of ß cells and protein synthesis in elderly people. In this review, we discuss regular physical activities or exercises to prevent and improve health, which is sarcopenia as decreased muscle mass and metabolic disorders as diabetes in the elderly.

Effect of Black Maca Supplementation on Inflammatory Markers and Physical Fitness in Male Elite Athletes.

Given the current lack of studies, the primary purpose of this study was to investigate the effects of black maca supplementation intake on changes in physical strength and inflammatory markers among elite athletes. Forty-four elite athletes were recruited for the present study. They included shooting athletes, racket sports athletes, and fin swimming athletes. The intake capsules contained 2500 mg of 100% concentrated black maca extract. Participants were instructed to take one capsule twice a day for eight weeks with pure water. Changes were seen in the ATP-PC systems and aerobic energy systems, particularly in the fin swimming athletes requiring aerobic energy systems. This effect is caused by increased antioxidant activity and influenced mitochondrial biosynthesis regulatory factors due to black maca supplementation intake. These findings provide preliminary evidence that elite athletes will benefit from taking black maca to improve their inflammation levels and physical fitness.

Effects of Black Maca supplement on isokinetics muscular performance of elite women's handball players: placebo-controlled, crossover study.

Background: The aim of this study was to investigate the changes in isokinetic muscular performance among female adolescent elite handball athletes with the supplementation of Black Maca (BM). Methods: Eight elite handball athletes were recruited for the present study. The intake capsules contained 2,500 mg of 100% concentrated BM extract and a placebo each, for 4 weeks. Isokinetic muscular performance and physical fitness were measured three times at 4-week intervals after the intake of BM and placebo, including baseline. Results: The one-way Analysis of Variance (ANOVA) analysis showed a significant improvement in 20 m-shuttle run (P < 0.001), 30°/s flexor (P < 0.01), and 120°/s flexor (P < 0.01) in isokinetic muscle function of the trunk, and 180°/s right extensor (P < 0.05), 180°/s left extensor (P < 0.05), and 180°/s left flexor (P < 0.01) in isokinetic muscle function of the knee, after BM supplementation. Post-hoc analysis indicated that the BM group had significantly higher results compared to the baseline and placebo groups in terms of 20 m-shuttle run, 30°/s flexor and 120°/s flexor of the trunk, 180°/s right extensor, 180°/s left extensor, and 180°/s left flexor of the knee. Conclusion: BM supplementation can have a positive effect on improving the performance of elite handball players who engage in high-intensity movements by enhancing their isokinetic muscle function and endurance.

The Association of Menstruation and Leisure-Time Physical Activity among Korean Female University Students: A Preliminary Study.

An active lifestyle elicits many health benefits. This study's aim is to understand the actual of leisure time physical activity (LTPA) of female university students in Korea who are experiencing stress due to, e.g., study and employment. LTPA is the degree of exercise participation in leisure time; it is cardiovascular and strength-based behavior occurring within recreation, exercise or sport and provides a positive effect on life satisfaction and psychological well-being. LTPA has been recommended as a method of reducing menstrual symptom severity. However, a lack of evidence exists to support a clear relationship between LTPA and menstruation in female university students. Health consciousness (HC) refers to the degree of interest in one's health, and Korean female university students pay considerable attention to their body shape, diet habits, and LTPA. This study investigated female university students (K University in Gangwon-do, D University in Busan, and U University in Ulsan) in three metropolitan cities in Korea. Specifically, after seeking cooperation from the person in charge of each university, the purpose of this study was explained. In addition, after promising to provide coffee coupons to students who wish to respond to the survey, cooperation was sought in recruiting research subjects through the person in charge of each university. In addition, a total of 36 surveys that did not have contents filled in fully or gave inconsistent answers were excluded among all survey participants. Chi-square test, t-test and univariate one-way ANOVA, and Pearson's correlation coefficient analysis were performed for between groups (HC, LTPA, intention to participate in LTPA). The LTPA results in relation to the menstruation patterns of Korean female college students are shown. First, there were no significant differences between menstruation (regular vs. irregular) and general LTPA during non-menstrual time periods (χ2 = 5.828, p < 0.212). However, female university students with regular menstruation patterns had higher LTPA after menstruation compared to female university students with irregular menstruation. Second, there were significant differences in the relationships among HC (p = 0.000), amount of LTPA (p = 0.002), and intention to perform LTPA (p = 0.002), according to the menstruation patterns (regular vs. irregular) of Korean female university students. In other words, those with regular menstruation patterns showed higher HC, amount of LTPA and intention to participate in LTPA than those with irregular menstruations. Third, there were significant differences in the relationship among HC (p = 0.000), amount of LTPA (p = 0.000), and intention to participate in LTPA (p = 0.000) according to LTPA of Korean female university students. Causation cannot be inferred from correlational studies. Therefore, female university students ultimately have different HC and participation in LTPA depending on menstruation regularity.

Variation in myokine and adipokine levels according to menstrual cycle following regular resistance exercise.

BACKGROUND: The purpose of this study was to analyze the differences between myokine and adipokine factors under stable conditions according to the menstrual cycle (luteal and follicular phases) and to investigate the effect of regular resistance exercise on the changes in myokine and adipokine factors according to menstrual cycle in obese female college students. METHODS: The study participants were female college students with a body fat percentage of 30% or more (N.=20), divided into two groups: luteal phase (N.=12) and follicular phase (N.=8). They performed regular resistance exercise three times a week, 60 minutes daily, for 16 weeks. Parameters measured include body composition via impedance, visceral fat area using computed tomography and myokine and adipokine factors in blood. RESULTS: Levels of BDNF (P<0.05), NGF (P<0.01), and adiponectin (P<0.01) were significantly increased in the luteal phase group after 16 weeks relative to the baseline values. Leptin (P<0.01) was significantly decreased in the luteal phase group after 16 weeks. Weight, Body Mass Index, %fat, and visceral fat area were significantly decreased in both groups after 16 weeks. Muscle mass was significantly increased in both groups after 16 weeks. CONCLUSIONS: Regular resistance exercise affected the reduction in visceral fat area and had a positive effect on body composition which might be altered favorably by myokines and adipokines. Thus, the timing of blood collection is very important in obese female college students.

Effect of Resistance Exercise on the Lipolysis Pathway in Obese Pre- and Postmenopausal Women.

Physical exercise may stimulate lipolytic activity within adipose tissue. Furthermore, resistance exercise may contribute to the more efficient reduction in adipose tissue mass and prevent the accumulation thereof in obese women. The purpose of this study was to examine the effects of regular resistance exercise for 12 weeks on the lipolysis pathway in women with obesity. Twenty-three pre- and postmenopausal women with body fat percentages of 30% or more were divided into the premenopausal group (n = 9) and the postmenopausal group (n = 14). All subjects participated in resistance exercise training for 12 weeks. Anthropometric and physical fitness tests were performed on all participants. Protein analyses were performed on extracted subcutaneous fatty tissue, and changes in the relevant protein levels in the samples were analyzed by Western blotting. All serum samples were submitted for enzyme-linked immunosorbent assay measurements of adipocyte factors. After 12 weeks, the adipose triglyceride lipase, monoacylglycerol lipase, and perilipin1 protein levels were significantly lower in the postmenopausal group than in the premenopausal group. The hormone-sensitive lipase protein levels were significantly higher in the postmenopausal group than in the premenopausal group. In addition, leptin concentrations were significantly decreased after resistance exercise in the postmenopausal group. Adiponectin concentrations were significantly increased after resistance exercise in both groups. These findings indicate that regular resistance exercise is effective in reducing the weight and body fat of obese premenopausal women, and in the secretion of adiponectin. On the other hand, postmenopausal women were found to have redeced weight and body fat, and were found to be positive for the secretion of adipokine factors. In addition, positive changes in lipolysis pathway factors in adipose tissue promote lipid degradation and reduce fat mass. Thus, regular resistance exercise shows positive changes in the lipolysis pathway more effectively in weight and body fat reduction in postmenopausal women than in premenopausal women.

Regular Leisure-Time Physical Activity is Effective in Boosting Neurotrophic Factors and Alleviating Menopause Symptoms.

BACKGROUND: The study investigated the effects of regular leisure-time physical activity on the parameters of cognitive function (plasma brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), and cathepsin B) and menopausal symptoms (the climacterium, depression, and cognitive impairment) in obese middle-aged women. METHODS: All subjects were middle-aged and obese women (n = 52, % body fat > 30%). The participants were divided into premenopausal (PRM) (n = 18, age = 47.56 ± 6.11 years) and postmenopausal (POM) (n = 34, age = 57.79 ± 5.68 years) groups. The participants completed a survey questionnaire related to depression and the climacterium, as well as cognitive tests. Physical activity was performed for 12 weeks. Blood samples from the forearm vein were analyzed after 12 h of fasting. Blood levels of BDNF, NGF, and cathepsin B were analyzed using an R&D kit. RESULTS: Regular leisure-time physical activity had a positive effect on reducing the percentage of body fat in premenopausal and postmenopausal obese women. In addition, the results of the questionnaire showed that regular exercise had a positive effect on body composition caused by lifestyle change and enhanced psychological stability. The BDNF concentration was significantly lower in postmenopausal than in premenopausal obese women. In addition, regular physical activity significantly increased the cathepsin B and NGF levels in postmenopausal obese women. CONCLUSIONS: Continuous leisure-time physical activity improved body composition and neurotrophic factors and alleviated menopausal symptoms in obese Korean women.

Effects of resistance exercise on adipokine factors and body composition in pre- and postmenopausal women.

The objective of the present study was to examine effects of resistance exercise for 12 weeks on adipokine factors and body composition in postmenopausal (POM) women to provide basic data for preventing obesity or metabolic syndrome caused by menopause. Subjects of this study were 35 premenopausal (PRM) and POM women with body fat percentages of 30% or more. They were divided into PRM (n=15) and POM (n=20) groups. All subjects participated in resistance exercise training for 12 weeks. All serum samples were submitted for enzyme-linked immunosorbent assay measurements of adipokine factors. Body weight, muscle mass, body mass index, and waist-to-hip ration showed significant differences between the two groups after training. In contrast, body fat percentage did not differ between the groups, although it was significantly lower in the PRM group after exercise. Physical fitness was significant differences between the two groups after training, including grip strength (left and right), sit and reach, sit-ups, and standing long jump. In addition, grip strength (left), sit-up, and side step tests were significantly increased after exercise in the PRM group. There were the significant differences in interleukin-6 and leptin levels between the two groups after training. Interleukin-6, interleukin-15, and adiponectin levels were significantly higher in both groups after training compared to those before training, although leptin levels were significantly lower after exercise in the PRM group. Regular resistance exercise was found to be effective in decreasing body fat in PRM women, and decreased leptin and increased adiponectin were positively significant in both groups.

Effects of detraining and retraining on muscle energy-sensing network and meteorin-like levels in obese mice.

BACKGROUND: Increased intramuscular peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) with exercise directly or indirectly affects other tissues, but the effector pathway of PGC-1α has not been clearly elucidated. The purpose of this study was to investigate the effect of exercise and/or dietary change on the protein levels of the soleus muscle energy-sensing network and meteorin-like (Metrnl), and additionally to analyze the detraining and retraining effects in high-fat diet (HFD)-induced obese mice. METHODS: One hundred male C57BL/6 mice were divided into normal-diet + sedentary (CO, n = 20) and HFD + sedentary (HF, n = 80) groups, and obesity was induced in the HF group through consumption of a 45% HFD for 6 weeks. The HF group was subdivided into HF only (n = 20), HF + training (HFT, n = 20), dietary change + sedentary (HFND, n = 20), and HFND + training (HFNDT, n = 20) groups, and the mice in the training groups underwent a treadmill training for 8 weeks, 5 times per week, 40 min per day. The HFT and HFNDT groups underwent 8-week training, 8-week detraining, and 4-week retraining. RESULTS: An 8-week training was effective in increasing the protein levels of soleus muscle AMP-activated protein kinase (AMPK), PGC-1α, and plasma Metrnl in the obese mice (P < 0.05). Moreover, exercise in obesity reduced body weight (P < 0.05), and exercise with dietary conversion was effective in reducing body weight (P < 0.05) and fat mass (P < 0.05) after 8-week training. 8-week detraining restored the increased protein level to the pre-exercise state, but, the previous exercise effect in body weight and fat mass (P < 0.05) of the HFNDT group remained until the end of 4-week detraining. 4-week retraining was effective in increasing the protein levels of soleus muscle AMPK, PGC-1α, blood Metrnl (P < 0.05), and reducing in body weight (P < 0.05) and fat mass (P < 0.05), when retraining with dietary change. CONCLUSIONS: The results of this study suggest that regular exercise is indispensable to reduce body weight and fat mass through upregulation of the muscle energy-sensing network and Metrnl protein levels, and retraining with dietary change is necessary to obtain the retraining effects more quickly.

The effects of detraining and training on adipose tissue lipid droplet in obese mice after chronic high-fat diet.

BACKGROUND: It is well known that exercise promotes lipolysis by stimulating the lipid droplet (LD) signaling pathway. However, few studies have been conducted to examine the effect of detraining with high fat diet (HFD) and training effects after long-term HFD. Here, we investigated the effect of detraining and training on adipose tissue LD pathway in diet-induced obese mice after continuous HFD. METHODS: Seventy male C57BL/6 mice were randomly assigned into a Normal diet + Sedentary group (ND, n = 10) or a High-fat diet + Sedentary group (HF, n = 50); in the HF group, obesity was induced by a 45% fat chow for six weeks. For the subsequent eight weeks, the HF group was randomly subdivided into an HF (n = 30) or an HF + training group (HFT, n = 20), and the HFT group was subjected to treadmill training while on an HFD. Following this eight-week period, the HFT group stopped exercising (HFT-DT group, n = 10), and the mice in the HF group were randomly subdivided into an HF (n = 10) or an HF + training group (HF-T, n = 10). After training and detraining, abdominal visceral fat was obtained and analyzed by histological staining and western blot. RESULTS: Treadmill exercise decreased body weight and fat mass (P <0.05), and increased the levels of PKA, perilipin1, CGI-58, ATGL, and HSL (P <0.05) after eight weeks of training. Following eight weeks of detraining, the levels of PKA and HSL were decreased (P <0.05); however, exercise after chronic HFD increased the levels of PKA, perilipin1, CGI-58, ATGL, and HSL (P <0.05), and decreased body weight and fat mass (P <0.05). CONCLUSIONS: Regardless of dietary restrictions, exercise is an effective treatment for obesity, owing to the regulation of LD signaling proteins. Moreover, the effects of regular exercise after chronic HFD were similar to those of exercise in the absence of HFD. Therefore, although obesity is induced by chronic HFD, exercise without dietary change is sufficiently effective for obesity treatment regardless of the preceding HFD period.

Effects of the optimal flexor/extensor ratio on G-tolerance.

[Purpose] The aim of this study was to examine the flexor/extensor ratio of the knee joints and compare it with the results of Korean Air Force students in G-tolerance test. [Subjects and Methods] The body composition of Korea Air Force students (n=77) was measured by an impedance method. A muscular function test was performed using a Humac Norm (USA) at angular speeds of 60°/sec and 240°/sec and an isokinetic muscular function test was also conducted. [Results] In the failed C and passing groups, muscle mass and fat percentages were significantly higher than those of students in the failed A group. The BMI of the failed C and passing groups were significantly higher than that of the failed A group. The group that passed had a significantly higher value of left knee 60°/sec flexion peak torque than the failed B group. Moreover, the total work of left knee extension of the failed C group and the passing group was significantly higher than that of the failed A group. The C group and the passing group had significantly higher values of the trunk 60°/sec flexor/extensor ratio than the failed A group, and the total work flexor/extensor ratio of the passing group was significantly higher than that of the failed A group. [Conclusions] Based on these results, balance the right and left knee flexor/extensor ratio, and a high flexor/extensor ratio of the trunk are required to endure a high G-tolerance test (+6G/30 sec). Moreover, an improvement in the maximum muscular strength is necessary to endure a situation of rapidly increasing acceleration in the early stage.

Diet change and exercise enhance protein expression of CREB, CRTC 2 and lipolitic enzymes in adipocytes of obese mice.

BACKGROUND: The study investigated the effects of regular exercise and diet changes on the change in metabolic processes of the cAMP-Response Element-Binding Protein-Regulated Transcription Coactivator (CRTC) family and its sub-lipolysis. METHODS: Four-week-old C57/black male mice received an 8-week diet of general formula (control, CO; n = 10) or a high fat diet (HF; n = 30) to induce obesity. Thereafter, the mice received another 8-week regimen of general formula CO (n = 10) diet, continuous HF diet (n = 10), switched to general formula (diet change, DC; n = 10) or switched to general formula + exercise (diet and exercise, DE; n = 10). RESULTS: The DE group displayed significantly lower body weight, abdominal fat and lipid profiles (p < 0.05). The DE group also displayed significantly lower (35 %) CRTC 2 activity than the CO (p < 0.05). Activities of adipose triglyceride lipase (ATGL), hormone sensitive lipolitic enzyme (HSL) and monoacylglycerol lipase (MGL) were significantly higher (51 %, 38 %, 49 %) in the DE group than the HF group (p < 0.05). MGL, there were no differences between the CO group, HF group, and DC group, with the DE group (70 %) being significantly higher (p < 0.05). CONCLUSION: Change in diet in the absence of exercise was not associated with changes in adipose tissue CRTC family lipase activity, indicating that lipolysis metabolic processes are effective only when diet and exercise are carried out together.

Exercise and dietary change ameliorate high fat diet induced obesity and insulin resistance via mTOR signaling pathway.

PURPOSE: The purpose of this study was to investigate the effect of exercise and dietary change on obesity and insulin resistance and mTOR signaling protein levels in skeletal muscles of obese rats. METHODS: Sixty male Sprague-Dawley rats were divided into CO (Normal diet) and HF (High Fat diet) groups in order to induce obesity for 15 weeks. The rats were then subdivided into CO, COT (CO + Training), HF, HFT (HF + Training), HFND (Dietary change), and HFNDT (HFND + Training) groups (10 rats / group). The training groups underwent moderate-intensity treadmill exercise for 8 weeks, after which soleus muscles were excised and analyzed. Data was statistically analyzed by independent t-test and One-way ANOVA tests with a 0.05 significance level. RESULTS: Fasting blood glucose, plasma insulin, and HOMA-IR in the HF group were significantly higher, as compared with other groups (p <.05). Protein levels of insulin receptor subunit-1 (IRS-1), IRS-2, and p-Akt were significantly higher in the HFT, HFND, and HFNDT groups, as compared with HF group. In addition, the protein levels of the mammalian target of rapamycin complex 1 (mTORC1) and ribosomal S6 protein kinase 1 were significantly decreased by exercise and dietary change (p <.05). However, mTORC2 and phosphoinositide 3-kinase were significantly increased (p <.05). CONCLUSION: In summary, despite the negative impact of continuous high fat intake, regular exercise and dietary change showed a positive effect on insulin resistance and mTOR signaling protein levels.

Effects of combined open kinetic chain and closed kinetic chain training using pulley exercise machines on muscle strength and angiogenesis factors.

[Purpose] This study investigated the effects of combined open kinetic chain and closed kinetic chain training using pulley exercise machines on muscle strength, anaerobic power, and blood levels of angiogenesis factors. [Subjects and Methods] Twenty male university students were equally divided between control and pulley training groups. The pulley-training group underwent 8 weeks of combined training. Open kinetic chain training consisted of 2 sets of 10 repetitions at 60% of one repetition maximum; closed kinetic chain training consisted of 2 sets of 10 repetitions of resistance exercise using the subject's own body weight. Isokinetic strength (trunk and knee), anaerobic power, vascular endothelial growth factor, angiopoietin-1, angiopoietin-2, and follistatin were analyzed. [Results] After 8 weeks, flexor and extensor muscle strength significantly increased in the trunk and knee; average and peak power also increased significantly. Angiopoietin 1 increased 25% in the control group and 48% in the pulley training group; vascular endothelial growth factor and follistatin increased significantly in the pulley-training group after 8 weeks. [Conclusion] Eight weeks of combined training using pulley exercise machines effectively increased biochemical factors related to muscle growth, as well as muscle strength in the trunk and knees.

Correlation between basic physical fitness and pulmonary function in Korean children and adolescents: a cross-sectional survey.

[Purpose] The purpose of the present study was to determine whether there was a correlation between basic physical fitness and pulmonary function in Korean school students, to present an alternative method for improving their pulmonary function. [Subjects and Methods] Two hundred forty healthy students aged 6-17 years performed physical fitness tests of hand-grip strength, sit and reach, Sargent jump, single leg stance, and pulmonary function tests of forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) using a Quark PFT. [Results] Muscle strength and power of boys improved in the late period of elementary school and middle school. Muscle strength of girls improved in the late period of elementary school. Analysis of factors affecting pulmonary function revealed that height, weight, BMI, and body fat significantly correlated with spirometric parameters. Right hand-grip strength, left hand-grip strength, and Sargent jump also significantly correlated with FVC and FEV1. [Conclusion] In order to improve the pulmonary function of children and adolescents, aerobic exercise and an exercise program to increase muscle strength and power is needed, and it should start in the late period of elementary school when muscle strength and power are rapidly increasing.

The effect of exercise on expression of myokine and angiogenesis mRNA in skeletal muscle of high fat diet induced obese rat.

PURPOSE: The purpose of this study was to investigate the effect of regular treadmill exercise on the mRNA expressions of myokines and angiogenesis factors in the skeletal muscle of obese rats. METHODS: Thirty two male Sprague-Dawley rats (4weeks old) were divided into the CO (control) and HF (high fat diet) groups. Obesity was induced in the HF group by consumption of 45% high-fat diet for 15 weeks. These groups were further subdivided into training groups (COT and HFT); the training groups conducted moderate intensity treadmill training for 8 weeks. Soleus muscles were excised and analyzed by real-time quantitative PCR. RESULTS: mRNA expression of myokines, such as PGC-1α, IL-6, and IL-15, in the COT and HFT groups (which conducted regular exercise), were higher as compared with the CO and HF groups (p < 0.05). Also, the levels in the HF group were significantly lower when compared with CO group (p < 0.05). Expression of angiogenesis mRNA, namely mTOR, VEGF, and FLT1, were significantly lower in the HF group, as compared to the CO group (p < 0.05). In addition, COT group had a higher expression of mTORC1, mTORC2, VEGF and FLT mRNA, than the CO group (p < 0.05); the HFT group also had higher expressions of mTOR, VEGF and FLT1 mRNA than the HF group (p < 0.05). CONCLUSION: These results indicate that mRNA expression of myokines was increased through the activity of muscle contraction, and it also promoted the mRNA expression of angiogenesis due to activation of mTOR. Thus, we conclude that not only under normal health conditions, but in obesity and excess nutritional circumstances also, regular exercise seems to act positively on the glycemic control and insulin sensitivity through the angiogenesis signaling pathway.

Effects of regular exercise on obesity and type 2 diabete mellitus in Korean children: improvements glycemic control and serum adipokines level.

[Purpose] The aim of the study was to clarify the effects of regular exercise on lipid profiles and serum adipokines in Korean children. [Subjects and Methods] Subjects were divided into controls (n=10), children who were obese (n=10), and children with type 2 diabetes mellitus (n=10). Maximal oxygen uptake (VO2max), body composition, lipid profiles, glucagon, insulin and adipokines (leptin, resistin, visfatin and retinol binding protein 4) were measured before to and after a 12-week exercise program. [Results] Body weight, body mass index, and percentage body fat were significantly higher in the obese and diabetes groups compared with the control group. Total cholesterol, triglycerides, low-density lipoprotein cholesterol and glycemic control levels were significantly decreased after the exercise program in the obese and diabetes groups, while high-density lipoprotein cholesterol levels were significantly increased. Adipokines were higher in the obese and diabetes groups compared with the control group prior to the exercise program, and were significantly lower following completion. [Conclusion] These results suggest that regular exercise has positive effects on obesity and type 2 diabetes mellitus in Korean children by improving glycemic control and reducing body weight, thereby lowering cardiovascular risk factors and adipokine levels.

Exercise training improves cardiac autonomic nervous system activity in type 1 diabetic children.

[Purpose] We investigated the effect exercise training has on cardiac autonomic nervous system (ANS) and cardiovascular risk profiles in children with type 1 diabetes mellitus (DM). [Subjects] Fifteen type 1 DM children (all boys; 13.0±1.0 years of age) were enrolled in the study. [Methods] The subjects received exercise training three times a week in a 12-week program. Each child was asked to walk on a treadmill to achieve an exercise intensity of VO2max 60%. ANS activity was measured by power spectral analysis of the electrocardiogram (ECG). Blood samples were obtained for serum lipid profiles. To evaluate Doppler-shifted Fourier pulsatility index (PI) analysis, a 5-MHz continuous wave Doppler (VASCULAB D10) set was used to measure forward blood flow velocity (FLOW) in the radial artery. [Results] Total and low-frequency (LF) power of heart rate variability increased significantly after exercise intervention. Total cholesterol (TC) levels were significant lower after exercise intervention. Total and high-frequency (HF) power were significantly correlated with higher TC levels, but diastolic blood pressure and HF was significantly correlated with lower TC levels. [Conclusion] Regular exercise intervention should be prescribed for children with type 1 DM.