Purpose In recent years, competition among companies has become more and more important to maximize the competitiveness of companies by improving their productivity through technological innovation. Increasing competitiveness through technological innovation is becoming an essential requirement for survival of companies. In order for companies to innovate, it is necessary to spend R&D investment and the government is strengthening various policy supports to do this. Athletic equipment industry classified as manufacturing industry in sports industry. In this study, considering the fact that manufacturing industry occupies a large part of Korea's R&D investment, we compared R&D intensities with athletic equipment industry and other industries. We also examined whether R&D investment has affected firm performance. Methods The data used in the analysis were extracted from KIS-DATA with KSIC codes of companies classified as sports and athletic goods manufacturing industry in the 9th Korean Standard Industrial Classification of National Statistical Office. The analysis period is five years from 2011 to 2015 to look at the current status. Looking at the number of companies extracted by year, it was 42 in 2011, 45 in 2012, 46 in 2013, 48 in 2014, and 39 in 2015. Results Research showed that the intensity of R&D of athletic equipment industry was 1.22% in 2011, 1.63% in 2012, 1.51% in 2013, 1.53% in 2014 and 1.30% in 2015. This was lower than the manufacturing industry, which was a category of athletic equipment industry, and lower than that of similar small and medium sized enterprises. The correlation between R&D intensities and the sales growth rate of firms showed a positive correlation in 2011 and 2015, but the correlation is not strong. Conclusion R&D investment in athletic equipment industry was not actively taking place, and R&D investment did not have a significant effect on the performance of the company.
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.
Purpose This study is a phenomenological research which tries to describe the subjective experience and to analyze multi-layered meanings, and it finds out the men's training experience and meaning. The purpose of this study is to investigate why the men do Yoga and what the subjective meaning of Yoga experience, and the study examines critically whether Yoga experience especially focused on women is against gender performance and dominant body discourse. Methods For the study, 6 middle & young-old aged men who do Yoga more than 6 months every week are selected as participants. Results The meaning of Yoga for middle & young-old aged men in their lives is as follows. First, it is hard for men to experience Yoga because of social and cultural background. Finding Yoga class which takes men's membership is difficult. Second, middle & young-old aged men's physical feature(interest in their health and disease) and personal background(women friendly daily life) become specific motivation to overcome the barrier to do Yoga. Third, Yoga is 'alterative training', not a training. Yoga is considered as a training which replaces the feature of training called men's sports previously. Fourth, Yoga has a meaning of 'healing' to have our own time. Fifth, Yoga is changed by itself in Yoga culture which is focused on women even though middle & young-old aged men do Yoga for a long time. Sixth, middle & young-old aged men realize that the feature of Yoga is not 'for only women', and they thought it is 'neutral training that men can do too.' Conclusion Consequently, the reason why middle & young-old aged men do Yoga is started from the motivation regarding physical characteristics and personal background, and the main purpose is to cure and to heal our bodies and mind. For them, Yoga means 'alternative training to fit their bodies' and 'their own time'. Moreover, old male adult's training experience and meaning are against gender performance in that it cause a crack in stereotyped gender sports area, but it is notable that there is no intention to resist the dominant gender body discourse.
This study was aimed at investigating the effect of head-tilt angle on autonomic nerve modulation immediately after a single bout of exercise in twenty-three healthy young males(age 21.96 ± .4 yrs). Post-exercise HRV was measured on supine(SUP), -15°head-down tilt(HDT), and +15°head-up tilt(HUT) followed by 20 min aerobic exercise with moderate intensity(40% of VO2max). As results, heart rate recovery during post-exercise on each tilt angle(SUP vs. HDT vs. HUT) had no significant difference(p> .05). Also, there were no significant difference in time and nonlinear domain index of HRV. On spectral analysis; however, frequency domain index(HF, LF/HF ratio, HF/TP ratio, HF nu, LF nu) had significant difference(p< .05) on each tilt angle at recovery. Especially, PNS reactivation index (HF, HF/TP ratio, HF nu) had significant increase on HDT compared to HUT(p<. 05) while SNS activation index (LF/HF ratio, LF nu) had significant decrease on HDT compared to HUT(p<. 05). Furthermore, there were significant interaction between recovery time elapsed and each tilt angle (except for HF/TP ratio). In conclusion, -15°head-down tilt promotes the effective cardiac vagus nerve reactivation immediately after a single bout of aerobic exercise.
The purpose of this study was to investigate the effect of wearing of safeguard devices on various blood ions (i.e., Na+, K+, Ca2+) concentrations, gas parameters (PO2, PCO2, hematocrit [Hct], hemoglobin [Hb], Saturated [Sat] O2), and energy substrates (i.e., glucose, free fatty acid [FFA], lactate) concentrations during Kumdo training. Research scope extended to examine the heart rate changes during each exercise sessions. In order to achieve the research goal, 10 male elite Kumdo players, who play for G city in Gyeongsangbuk-do, were participated, and their mean maximum oxygen uptake level was 51.2(±6.1)mL· kg-1min-1. All subjects undertook Kumdo training sessions twice, which carefully pre-planned and consisted of routinely carrying out exercise program. Training period for each session was 80 min long including 10 min each for warm-up and warm-down period, but the conditions with wearing body protection devices were different following either with wearing complete set of safeguard devices or without wearing any safeguard devices except general training cloth. Heart rate was measured by every minute interval. K+ and Ca2+ showed interaction effect between the conditions with wearing safeguard devices and conditions with time of Kumdo training. Hct and Hb level significantly increased after 60 min Kumdo exercise regardless of wearing safeguard devices. Kumdo training induced dropping of blood pH independently with wearing safeguard device conditions, however the values and/or concentrations of PO2, Na+, glucose, lactate, Sat O2were significantly increased. Heart rate was maintained marginally higher values throughout exercise period when safeguard devices were worn. Based on these results, it was concluded that wearing the safeguard devices could possibly be causing a physiological metabolic changes, and this may be drawn by increased body fluid loss and energy expenditure. Further study should be undertaken to examine the effects of wearing safeguard devices on hitting intensity and hormone secretion and concentrations, that closely associated with body fluid and ion balance during Kumdo exercise and/or training.
The purpose of this study was a investigate the endothelial function of prehypertensive during dynamic exercise. Hypothesis of this study was to impair the endothelial function in prehypertensive compared to normtensive during dynamic handgrip exercise. Eleven healthy prehypertension (24±2 yrs) and ten healthy normotensive (25 ± 2 yrs) were recruited in this study. Participants were performed dynamic handgrip exercise in one contraction per second at 30% of maximum voluntary contraction for three minutes. Vascular (blood vessel diameter, blood flow) and cardiar response (stroke volume, heart rate and cardiac output) were measured at rest and during exercise. Flow mediated dilation (FMD) was decrease significantly in prehypertensive less than normotensive (p<0.05) at rest, and vasodilation of prehypertensive was reduced significantly less than normitensive during exercise (p<0.05). All the cardiovascular responses were aot significantly different at rest and during exercise between prehypertensive and normotensive. These results suggest that endothelial function is impaired in prehypertensive compared to in normotensive
The aim of this study was to acquire essential information regarding Ri Se Gwang motion(element group Ⅱ, difficulty 6.4 point, double Tsukahara with tucked 1/1 twist), which Ri Se Gwang of North Korea performed during the final vault event of artistic gymnastic at Incheon Asian Game 2014, by analyzing motional characteristics. Firstly, Ri Se Gwang technique had second jump airborne time of 1.07 seconds and airborne height of 2.91m, which have great influences on the success of technique while having horizontal and vertical velocity of 2.73 m/s and 3.87 m/s, respectively, at the takeoff. These were sufficient jump motion for successful accomplishment of the technique however flight pattern was somewhat small which was mainly oriented vertically when compared to previous studies of Yeo and YANG Hak Seon 2 techniques. Secondly, blocking angle of vault contact was small at 9 degrees while having very small takeoff angle of 79 degrees. However, it had fast average trunk rotational velocity of 545 deg./s at the vault contact phase by rapidly bending trunk from the board takeoff until approaching the vault leading to achieve fast trunk rotational velocity of 452 deg./s after the take off in order to complete the airborne rotation successfully. Thirdly, the preparation phase of Ri Se Gwang technique had a distinct characteristics that the trunk was rapidly bent during the approach to the vault attempting aggressive blocking which leads to vertically oriented flight. It showed that this characteristic assists the motion of thigh snatch and the regulation of twist which strengthen airborne rotation for airborne rotational motion. And it also showed that sufficient landing and twist angles at the landing phase are possible with free rotational motion if the height of second jump reaches 3 m.
It has been reported that continuous exercise and bright light exposure improved resistance to stress and reduced depression and anxiety, which were attributed to enhancing neurotransmitter GABA exocytosis and stimulating neurogenesis. In this study, the effects of treadmill exercise and bright light exposure on the expression of GABAAreceptor activity, calcineurin and calcineurin calcium signaling pathway-depended NFATc4, neurogenesis-related protein Cdk5 and specific regulator factor of Cdk in neurogenesis p35 in the hippocampus of rats were investigated by western blot assay. The expression of GABAAreceptor, Cdk5 and p35 significantly increased in the exercise+light group compared to the control group and the light group. The expression of KCC2 and NFATc4 significantly increased in the exercise+light group compared to all the other groups. And the expression of calcineurin significantly increased in the exercise+light group compared to the control group. The overall results showed that exercise and bright light stimulated neurogenesis of the hippocampus in rats and had positive effects on improving the brain neuronal function.
The purpose of this study is to investigate the influence of resistance training with different exercise intensities on heart rate variability(HRV) in habitual smokers. Twenty-eight healthy young smokers participated in this study were randomly divided into three groups; CON(control), LRT(low-intensity resistance training; 50% 1RM), and HRT(high-intensity resistance training; 70%1RM), respectively. LRT and HRT groups performed an 8-week resistance training(4 upper- and lower body exercises) using weight training machines, whereas CON group maintained their regular activities. All groups were evaluated basal body composition, hemodynamic parameters, HRV as autonomic nervous function, and muscular strength (1RM and isokinetic test) before and after the 8-week training. To assess the effect of 8-week training with different intensities on autonomic regulation, time and frequency domain indices of HRV were calculated from 5min R-R interval recording. As results, both LRT and HRT groups increased baseline 1RM and isokinetic strength compared to CON group. Meanwhile, high-frequency power reflecting parasympathetic activity was significantly increased in HRT compared to CON group. In addition, normalized low frequency power(LF nu) indicating a shift of sympathovagal balance towards sympathetic predominance significantly decreased while normalized high frequency power(HF nu) which reflects vagal predominance significantly increased in HRT compared to CON group. Furthermore, improved cardiac autonomic regulation and parasympathetic activation had significant association with increased muscular strength. Overall, the 8-week training has enhanced muscular strength in both training groups, particularly autonomic balance improved in young habitual smokers with high intensity resistance training.
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.
