[Purpose] The purpose of this study was to determine the influence of complex exercise and chromium supplement on healthe-related physical fitness, appetite regulating hormones, and diabetes risk factors in obese elementary school students. [Methods] The subjects were 32 obese elementary students over 25 kg/m2 to BMI, 8 complex exercise with high chromium supplement group (CE+HC), 8 complex exercise with low chromium supplement group (CE+LC), 8 complex exercise with placebo group (CE+PL), and 8 placebo group (PL). The subjects have performed the exercise program for 70 minutes a day and 3 times a week with aerobic and anaerobic exercise during 12 weeks. Also, low and high chromium supplement group took a peel 50 ug and 400 ug respectively at the same time and place. [Results] There were significant decreases in body fat to CE+HC compared with CE+PL (p<.05) and significant increase in muscle mass compared with CE+PL (p<.05). However, there were no significant differences in body weight, BMI, muscular strength, muscular endurance, and flexibility between groups. For appetite regulating hormones, there is a significant difference to ghrelin in CE+HC compared with CE+PL (p<.05) and there were significant differences to glucose and insulin significantly decreased in CE+HC compared with CE+PL (p<.05) in diabetes risk factors. [Conclusion] In conclusion, there were positive responses for body composition and diabetes risk factors for the twofold cases through complex exercise and high chromium supplement, but not for physical fitness and appetite regulating hormones.
Although delayed heart rate recovery (HRR) and impaired autonomic nerve system (ANS) modulation after acute exercise are related with cause of cardiovascular disease (CVD) and mortality, studies evaluating ANS changes with local exercise are still unsatisfied. Thus, this study aimed at investigating the modulation of ANS-related parameters, followed by upper or lower body exercise. Eleven male without cardiovascular and orthopedic diseases measured basic body composition, resting blood pressure (BP), and heart rate variability (HRV). This study based on randomized cross-over design; AE composed with arm-ergometer, and LE involved with leg cycling. Participants had at least one week wash-out between each exercise, also there was no cool-down after exercise. All sessions were performed with intensity of 50 % target heart rate for 30 min. With measurement of Rating of perceived exertion (RPE) during every 10 min, HRV was measured Kubios HRV software using R-R intervals collected with Polar RS800CX in post-exercise recovery (for 30 min). As a result, heart rate (HR) and RPE were same (p > 0.05) through the experiment. As results of this study, SDNN and rMSSD in time domain on LE were higher than on AE during post-exercise recovery. When LE compared with AE used by Poincare plot, both parasympathetic reactivation (SD1) and autonomic nerve regulation (SD 2) on LE were higher than AE. Immediately after submaximal exercise, the high-frequency component on LE was significantly greater compared to AE. Also, the LF/HF ratio and LF nu reflecting sympathetic activity were higher on AE than LE. In contrast, the HF/TP ratio and HF nu reflecting vagal tone were greater on LE than AE. In conclusion, this study suggested regional lower body exercise recovers more sufficient than regional upper body exercise after submaximal aerobic exercise at same HR. Local exercise like leg cycling needs a careful approach to apply for accurate exercise prescription and effective training.
Lactate was considered a dead-end waste product of glycolysis due to lack of oxygen. Accumulating lactate in the muscle and blood was viewed only as a major cause of muscle fatigue and tissue damage. Furthermore, buildup of lactate due to glycogen re-synthesis is thought to cause excess oxygen consumption (oxygen debt) after exercise. However, research has also shown lactate to be an important mediator in numerous metabolic processes and a fuel for aerobic metabolism. Lactate is not metabolic waste, but a major player in cellular and whole body metabolism. Lactate can be used within the cell (intracellular lactate shuttle) or be transported through the cytoplasm or blood to be used by other cells (cell-cell lactate shuttle). Lactate shuttle hypothesis has helped in identifying and understanding the link between the glyoclyic and oxidative pathways, and identified lactate as a major energy source and gluconeogenic precursor. Therefore, the purpose of this review was to better understand the physiological roles of lactate at rest and during exercise, and the concept of lactate shuttle with implications for clinical practice.
PURPOSE Blood pressure (BP) in hypertensive individuals is reduced by the accumulation of post-exercise hypotension (PEH) induced by a long period of training. This study aimed to investigate the effects of intensity of two different aerobic exercises with identical energy expenditure on post-exercise blood pressure and cardiovascular function in prehypertensive men. METHODS Eleven prehypertensive men in their 30s participated in two trials repeatedly. In the first trial, the exercise was moderate in intensity and continuous (MICE) with 70% of VO2max, and the exercise in the second trial was high-intensity interval exercise (HIIE) with 50% and 90% of VO2max. Each exercise was performed for 30 min, and the variables related to BP and cardiovascular function were measured at certain times for 1 hr during the recovery phase. RESULTS Our main findings are as follows: (1) Systolic blood pressure was significantly lower at 30 and 45 min of recovery time than the baseline in the HIIE trial, and systolic blood pressure was significantly lower in the HIIE trial than the MICE trial at 10, 15, and 30 min of recovery time. (2) The rate pressure product was significantly higher in the HIIE trial than the MICE trial at 15, 30, 45, and 60 min of recovery time. (3) The heart rate was significantly higher in the HIIE trial than the MICE trial at 15, 30, 45, and 60 min of recovery time. (4) Stroke volume was significantly lower in the HIIE trial than the MICE trial at 30 min of recovery time. (5) Cardiac output was significantly higher in the HIIE trial than the MICE trial at 15 min of recovery phase. (6) Total vascular conductance was significantly higher in the HIIE trial than the MICE trial at 15 and 30 min of recovery phase. (7) Total peripheral resistance was significantly lower in the HIIE trial than the MICE trial at 15 and 30 min of recovery phase. CONCLUSIONS The HIIE shows a higher cardiovascular stress than MICE; however, HIIE contributes to the augmentation of PEH and improvement of cardiovascular function. Therefore, HIIE rather than MICE should be suggested in BP control and enhancement of cardiovascular function in prehypertensive males.
Purpose The study examined the effects of a 12-week high intensity circuit training (HICT) on abdominal fat, physical fitness, blood lipids, and insulin resistance in middle-aged obese women. Methods Thirty obese women, aged 32-48 yrs, were recruited and randomly assigned to either HICT group (TR; n = 15) or control group (CON; n = 15). Subjects in the TR group participated in HICT of which resistance exercise and aerobic exercise were performed with a duration of 40 min/session and 3 sessions/wk for 12 weeks, whereas subjects in the CON group were asked to maintain their normal life patterns. Dependent variables included abdominal fat area, body composition, physical fitness, blood lipids profiles, and insulin resistance index. Analysis of variance with repeated measures with Bonferroni corrections was used to compare the outcomes between two groups. Results Main findings of the present study were as follows: 1) compared to the CON group, the TR group had significant reductions in overall (i.e., body mass index and percent body fat) and abdominal obesity (i.e., waist circumference, total abdominal fat area, visceral fat area, subcutaneous fat area, and visceral fat area-subcutaneous fat area ratio), 2) compared to the CON group, the TR group had significant improvements in health-related physical fitness (i.e., muscular strength, muscular endurance, muscle power, flexibility, balance, and cardiorespiratory endurance), and 3) compared to the CON group, the TR group had significant improvements in fasting lipids, glucose, insulin, and insulin resistance. Conclusions The current findings of the study suggested that HICT would be an effective exercise intervention to improve metabolic complications associated with obesity and poor physical fitness in obese middle-aged women.
PURPOSE The purpose of this study is to analyze the type of and interest in home training video contents using the YouTube platform. METHODS Web crawling was performed using Python and a total of 3,937 sets ofvideo information (title, content, number of views, upload date) were obtained, 3,155 of which were finally selected for the study material. Overlapping and unrelated content were excluded. The data of text underwent 3 stages of preprocessing, the TF and TF-IDF of the keywords were calculated to identify the main keywords, and the LDA algorithm was applied in the topic modeling to successfully identify the types. In order to understand the level of interest by type, the number of views was subdivided into the percentage of the assigned type. RESULTS First, the types of home training videos were classified into bare whole body exercise for aerobic and muscular power strengthening, Pilates exercise for core and upper body strengthening, upper body exercise using tools, lower body line exercise, posture correction and upper body stretching exercise for pain relief, hip-up exercise, dance and tabata exercise for diet, diet and lower body correction stretching exercise for diet, and bare body exercise for core and lower body strengthening. Second, it was found that the proportion and interest were high in the contents of bare whole body exercise for aerobic and muscular power strengthening, dance and tabata exercise for diet, diet and lower body correction stretching exercise for diet. CONCLUSIONS The findings of this study may provide baseline data about the development of the active online home training videos in the market.
This study aims to suggest the guide line for weight category sports(Taekwondo, Judo, Wrestling, Weightlifting, and Boxing) who have to lose weight to pass weigh-in before games. Reference data was collected from RISS, Medline, PubMed, SciELO and effects of short term weight loss on physiological variables(body composition, physical fitness, blood components, oxidative stress and hormone, immune function) were analyzed. Also, weight loss procedures for weight category sports athletes were analyzed in details. The results of the research are as follows: weight category sports athletes prefer short term (3~5 days) weight loss methods (3~5%) with dietary control, sweating and exercise. Physical changes caused by the loss in body weight, fat-free mass, and BMI, however, do not affect body fat percentage. Different changes of physical strength element depend on weight reduction period. In short term weight loss method, anaerobic exercise capacity, muscular strength, and reaction time partially decrease and affect staying power. In contrast, long term weight loss method do not affect aerobic and anaerobic exercise capacity. Furthermore, most of previous studies show that blood component change has negative effect on body water balance, stress-related hormone, and immune function. In conclusion, short term weight loss method negatively affects athletic performance of weight class competition athletic. Therefore, careful long term weight loss methods are recommended with dietetic consideration to prevent dehydration during weight loss period. Excessive weight loss on lightweight athlete should be prevented by institutional basis as well.
It has been known that β-alanine supplementation induce the increment of carnosine in vivo and was effective in delaying fatigue by buffering the hydrogen which was formed during exercise. This study was designed to investigate the effects of 4 weeks of β-alanine supplementation on physical fitness and blood lactate concentration in middle school soccer players. Nineteen middle school soccer players were randomly assigned to either one of two groups, i.e., β-alanine group (n=10) and placebo group (n=9). Subjects in β-alanine group consumed β-alanine 2 g/day during 1st and 2nd week, as well as 3 g/day during 3rd and 4th week, whereas subjects in placebo group consumed maltodextrin in the same manner. All subjects ate same menu and trained same amount at the same training camp during the intervention period. Body composition, aerobic capacity, anaerobic capacity, isokinetic function, and blood lactate concentration during maximal GXT were measured at pre- and post-test. Main results of the present test were as follows: 1) Fat mass and percent body fat decreased significantly in β-alanine group. 2) No significant changes were found in variables related to aerobic capacity in both groups. 3) Average power increased significantly in β-alanine group. 4) Isokinetic muscular endurance increased significantly in β-alanine group. 5) Blood lactate concentration did not change in eithet group; however, blood lactate concentration immediately after maximal GXT in β-alanine group tended to be increased more than placebo group. It was concluded that β-alanine supplementation would have positive effects for improvement of body composition, anaerobic capacity, and muscular endurance in middle school soccer players.
Purpose The purpose of the study was to determine difference of body composition, bone mineral density and health-related fitness by physical activity level in young women. Methods A total of 90 women aged 19-29 years participated in this study. The subjects were divided into three groups (low, middle, and high level) according to the physical activity level estimated by bone-specific physical activity questionnaire(BPAQ). Body height and weight were measured. Body composition parameters including four sites of bone mineral density(BMD) were estimated by DXA (Hologic, QDR-4500, USA). Health-related fitness tests was assessed using sit & reach, grip strength, sit-ups, and VO2max. Statistical analysis was performed using SAS version 9.4. All data were presented in terms of means and standard deviations. One-way ANOVA was applied to determine difference of dependent variables by physical activity level. Duncan's multiple range test was used as a post-hoc test. The statistical significance level was set at p < .05. Results There were significant differences on body weight(F = 4.867, p = .01), body mass index(F = 5.053, p = .008) and fat-free mass(F = 8.364, p = .0001) among the three groups. Significant differences were found on whole body BMD(F = 16.730, p = .0001), lumbar BMD(F = 11.480, p = .0001), femur BMD(F = 42.182, p = .0001) and forearm BMD(F = 5.560, p = .005) among the three groups. There were also significant differences on sit and reach(F = 11.433, p = .0001), sit-ups(F = 17.972, p = .0001), VO2max(F = 3.106, p = .05) and duration of GXT(F = 7.479, p = .001). Conclusions There were differences on body composition, bone mineral density and health-related physical fitness by physical activity levels. Nevertheless, the questionnaire used in this study was not able to judge participation in various exercise types including aerobic exercise or resistance exercise. Therefore, in the future study, longitudinal study considering various types of physical activity and dietary intake will be needed.
