Purpose The purpose of this study is to deeply understand what high school student athletes are doing as athletes and how they are transformed into student athletes from studying and exercising simultaneously. Through this, to understand the life of student wrestlers and to provide basic data for rational improvement of school athletic department. Methods Participants of the study selected one student in the second grade and two students in the third grade at Woosu high school in metropolitan. Data was collected through in-depth interviews, participant observation, and document analysis. The collected data was analyzed using Domain Analysis and Taxonomic Analysis by Spradley(1979). To assure the credibility of the data, additional checks and analysis were conducted with the participants, and the research process was examined by experts. Moreover, the common contents of the data were included in the research results with multilateral verification. Results Woosu high school wrestling student athletes were recognized as athletes as a training life to lose their dreams, a school life to stop their work. However, since student athletes have been studying and exercising together, they have been transformed from a trainee to a motivated active, a student who is reborn in the school community, and transformed a reflective student athlete to an immature player on a daily life. Conclusion The policy of the school athletic department to study and exercise together has a positive effect on student athletes and has a good effect. The introduction and practice of this system can expect true student athletes and establish elite physical education right away.
Purpose The purpose of this study was to develop the new indirect method assessing maximal oxygen uptake (VO2max) using heart rate (HR) and accelerometer during walk exercise. Methods One hundred seven participants (55 male, 52 female) performed a graded exercise test to determine VO2max and two types of 1,600 m walk exercises (fast walk and pace controlled walk). The equations for estimating VO2max was developed by stepwise multiple regression. The validity of developed equations tested through the correlation between measured VO2max and estimated VO2max, was assessed by predicted residual sum of squares, and Bland-Altman plotting. Results VO2maxwas correlated with time, and HR/activity count per minute (ACM) measured in pace controlled walk exercise at all distance (400 m, 800 m, 1,200 m, 1,600 m). The equations were valid significantly and their multiple correlation coefficients or standard estimated error were similar to that Åstrand-Rhyming cycle ergometer test or Rockport 1 mile walk test. Using HR/ACM in pace controlled walk (400 m), it was possible to estimate VO2max(R2: 0.675, %SEE: 10.7). The equation was: VO2max=121.659+6.656×Gender-0.865×Age-9.540×Time-2460.952×HR/ACM (Gender, 0=female, 1=male: Time, hundredth of a minute: HR, heart rate: ACM, activity count per minute). Conclusion Estimation equations developed in this study are considered to estimate VO2max through a shorter distance, or a lower intensity of walk exercise. It is required studies to target a wide range of ages or to develop walk test on a lower bpm.
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.
Purpose The purpose of this study was to determine the effectiveness of six-weeks intermittent hypoxic training at 3,000 m hypobaric hypoxic condition on aerobic and anaerobic exercise capacity in competitive swimmers. Methods South Korean swimmers (n=20) were randomly assigned into training at sea-level (n=10, intermittent normoxic training group; INT) and training at 526 torr corresponding to 3,000 m hypobaric hypoxic condition (n=10, intermittent hypoxic training group; IHT). The participants completed an aerobic continuous treadmill training (30 min) within 80%HRmax and anaerobic interval bicycle training (10 times; 2 min of exercise and 1 min of rest) for 30min within 90%HRmax in each environment. We compared their aerobic and anaerobic exercise capacity before and after six-weeks of training. Exercise frequency was 1 hour, 3 days per a week, and during 6 week. Results In aerobic exercise capacity, PWC at 75%HRmax, estimated VO2 max, and exercise time were increased by training in only the IHT group. Estimated VO2 at 75%HRmax was increased by training in both groups, but presented a larger increase tendency in the IHT group compared with the INT group. In anaerobic exercise capacity, peak anaerobic power and fatigue index were increased by training in only the IHT group. Blood lactate level after wingate test were decreased by training in both groups, but the IHT group have a lower blood lactate level in after training compared with the INT group. Conclusion In our study, we did not measure to various dependent variables for support to enhancement of aerobic and anaerobic exercise performance. However, these results showed that the IHT method may be effective in improvement of exercise performance in competitive swimmers who participates in a variety of events from short to long distance.
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 The purpose of this study was to establish the criteria for measuring acute muscle fatigue using tensiomyography (TMG) by quantifying the trend of changes in TMG variables. METHODS Searches were conducted in the Web of Science and Pubmed databases using the keyword “Tensiomyography”. Sixteen studies which used TMG to measure acute muscle fatigue caused by acute exercises in rectus femoris or biceps femoris were included. All statistical data analyses were performed using Comprehensive Meta-Analysis software program. RESULTS The meta-analysis results indicated that the biceps femoris showed a significant (p<.05) decrease in all TMG variables of the elite athletes. Also, in the overall effects of maximum displacement and mean velocity until 90% Dm (Vc90) showed a significant (p<.05) decreasing trend. The rectus femoris showed a significant (p<.05) decreasing trend for maximum displacement (Dm) in the average person, while contraction time (Tc) showed a decreasing trend in elite athletes and overall. CONCLUSIONS These results suggest that TMG could be used as an indicator of muscle fatigue indicator, and will help to develop a more proper protocol to test the response of the body to muscle fatigue.
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 purpose of this study was to investigate the effects of 8-week aerobic exercise and polyphenol intake on body composition, cardiovascular response, vascular endothelial function, and physical fitness at rest and during exercise in prehypertensive men. METHODS The study included twenty-eight males in their 20-30 years of age with prehypertension. Participants in the aerobic exercise + polyphenol intake group (EX + PP; n = 14) performed aerobic exercise three sessions/week, 30 min/session, at 65% of the heart rate reserve, and consumed polyphenol (grape seed extract 300 mg) for 8 weeks. Participants in the aerobic exercise + placebo intake group (EX + PL; n = 14) performed the same aerobic exercise; however, they consumed placebo instead of polyphenol. All independent variables were measured at pre-test and post-test, and the data were analyzed. RESULTS The main results of the study were as follows: 1) SBP and MAP at rest decreased significantly in EX + PP, while MAP decreased significantly in EX + PL group. 2) In the EX + PP group, CO increased significantly, whereas DBP, MAP, and TPR decreased significantly during the hand grip exercise. In contrast, CO decreased significantly, while DBP and TPR increased significantly in the EX + PL group during the hand grip exercise. 3) Regarding vascular endothelial function, % FMD increased significantly in EX + PP group. 4) Sit-up increased significantly in both EX + PP and EX + PL groups; however, sit-and-reach in EX + PP group was significantly higher than that in EX + PL group at post-test. CONCLUSIONS The findings of this study showed that the 8-week aerobic exercise would have positive effects on body composition, cardiovascular response, and physical fitness at rest and during exercise in hypertensive men. Additionally, polyphenol intake would contribute more towards reduction of blood pressure at rest and during exercise and improvement of vascular endothelial function.
The purpose of this study was to examine whether β-alanine ingestion for 8 weeks can regulate isokinetic knee strength, and 3km record in middle-long distance woman cyclists. Fourteen middle-long woman cyclists participated in this study and were divided into two groups; training group with beta-alanine ingestion and training group with placebo ingestion. All subjects took in beta-alanine or placebo supplement three times per a day for 8 weeks. Physical activity was evaluated by measuring the isokinetic muscular strength and 3km record before and after intervention for 8 weeks. As a results, in isokinetic test, there were significant interrelationships in peak torque of the right and left flexors at 60°/sec, peak torque of the right and left extensors at 180°/sec, peak torque of the right flexors at 180°/sec. In 3km record, result showed a significant interrelationship by groups and time. The results of present study provide evidence that beta-alanine supplement may be effective to increase physical activity and competition record in middle-long woman cyclists.
PURPOSE Since the COVID-19 pandemic, the demand for home training, with exercises or workouts at home, has steadily increased. As a result, the popularity of home training YouTube content, which shows how to use exercise equipment or workouts without professional influence, has also increased. Therefore, this study focused on the characteristics of YouTube home training content (specialization, diversity, and interaction), personal health awareness, exercise awareness, and expectation-confirmation model to identify which required exercise continuation intention through YouTube home training. METHODS SPSS and AMOS software were used to conduct frequency, reliability, and confirmatory factor analyses, as well as to conduct correlation analysis and construct a structural equation model. RESULTS First, health and exercise awareness had a positive effect on confirmation. Second, among the characteristics of home training content, only specialization had a positive effect on perceived usefulness. Third, confirmation had a positive effect on perceived usefulness and viewing satisfaction, perceived usefulness had a positive effect on viewing satisfaction and exercise continuation intention, and viewing satisfaction had a positive effect on exercise continuation intention, which proved the expectation-confirmation model in this study. CONCLUSIONS To increase exercise continuation intention through home training YouTube content, creators need to produce professional content that can stimulate viewers' internal motivation.
