著者

Masayuki Konishi Masaki Takahashi Naoya Endo Shigeharu Numao Shun Takagi Masashi Miyashita Taishi Midorikawa Katsuhiko Suzuki Shizuo Sakamoto

出版者

一般社団法人日本体力医学会

雑誌

The Journal of Physical Fitness and Sports Medicine (ISSN:21868131)

巻号頁・発行日

vol.2, no.1, pp.121-126, 2013-03-25 (Released:2013-04-08)

参考文献数

31

被引用文献数

1 2

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The aim of this study was to investigate the effects of one night of sleep deprivation on maximal fat oxidation during a graded exercise test. Ten healthy young males underwent two 2-day control and sleep deprivation trials. Participants were allowed normal sleep from 2300 to 0700 for the control trial, whereas they were required to stay awake for 34 h during the sleep deprivation trial. At 1700 on day 2, participants performed a graded exercise test to exhaustion on a treadmill; this allowed us to determine maximal oxygen uptake and maximal fat oxidation. Before and immediately after the graded exercise test, blood samples were collected in order to measure glucose, insulin, free fatty acid, and triglyceride concentrations. Plasma glucose concentrations were significantly higher in the sleep deprivation trial than in the control trial before the graded exercise test. Serum insulin and free fatty acid concentrations were not significantly different between the two trials. Serum triglyceride concentrations were significantly lower in the sleep deprivation trial than in the control trial. The maximal fat oxidation rate, oxygen uptake, and heart rate at maximal fat oxidation intensity, during the graded exercise test, were not significantly different between the two trials. These findings suggest that maximal fat oxidation during graded exercise is unaffected by one night of sleep deprivation.

著者

Masaki Takahashi Katsuhiko Suzuki Hideki Matoba Shizuo Sakamoto Shigeru Obara

出版者

一般社団法人日本体力医学会

雑誌

The Journal of Physical Fitness and Sports Medicine (ISSN:21868131)

巻号頁・発行日

vol.1, no.1, pp.183-189, 2012-05-25 (Released:2012-08-22)

参考文献数

36

被引用文献数

2 7

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The purpose of this study was to investigate the effects of three different intensities of exercise on oxidative stress and antioxidant capacity. Eight healthy male subjects performed three different intensities of exercise for 20 minutes: (1) 70% anaerobic threshold (AT) (light intensity, LI), (2) 100% AT (moderate intensity, MI), and (3) 130% AT (high intensity, HI) on a cycle ergometer. A control (C) trial was conducted under resting conditions. Blood samples were taken pre-exercise, immediately and 30 min after exercise. In the HI trial only, the concentrations of plasma derivatives of reactive oxygen metabolites (d-ROMs) were significantly higher immediately (P<0.01) and 30 min after exercise (P<0.05) than at pre-exercise. Furthermore, plasma trolox equivalent antioxidant capacity was significantly higher immediately after exercise in the HI trial (P<0.01). And, plasma glutathione peroxidase (GPX) activity was significantly higher immediately after exercise than at pre-exercise in the MI (P<0.05) and HI trials (P<0.01). These data suggest that 20 min of pedaling exercise above the AT level may increase ROS production, while endogenous enzyme activity (especially GPX activity) or non-enzymatic antioxidants may modulate exercise-induced ROS generation. Thus, exercise under the AT level induces very little oxidative stress damage in young people.

著者

Kenneth Vitale Shawn Hueglin

出版者

The Japanese Society of Physical Fitness and Sports Medicine

雑誌

The Journal of Physical Fitness and Sports Medicine (ISSN:21868131)

巻号頁・発行日

vol.10, no.1, pp.1-11, 2021-01-25 (Released:2021-01-13)

参考文献数

61

被引用文献数

5 10

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Interest in vegetarian and vegan diets continues to grow, not only in the general population, but in the high-performing athlete. Vegetarian diets may lower risk of chronic diseases and have proposed ergogenic benefits to the athlete regarding exercise performance and enhanced recovery. However, controversy and confusion exist in the literature regarding vegetarianism. Traditionally, a vegetarian or vegan diet was considered low in certain micronutrients (iron, zinc, calcium, iodine, vitamin A, B2, B12, D), as well as protein, omega-3 fatty acids, and total energy needs. However, a vegetarian diet typically contains higher complex carbohydrates, dietary fiber, magnesium, nitrates, folic acid, vitamin C and E, carotenoids and other phytochemicals which may offer certain performance benefits to the athlete. This review summarizes the current literature on the benefits of a vegetarian diet specific to the athlete, clarifies nutritional requirements, and provides insight on the potential performance benefits. With proper meal planning, an athlete can meet all their nutritional needs with foods derived from plants without any loss in physical performance.

著者

Tadayoshi Miyamoto

出版者

The Japanese Society of Physical Fitness and Sports Medicine

雑誌

The Journal of Physical Fitness and Sports Medicine (ISSN:21868131)

巻号頁・発行日

vol.5, no.5, pp.329-337, 2016-11-25 (Released:2016-11-10)

参考文献数

18

被引用文献数

2 2

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The respiratory control system is an important chemoreflex-feedback control system that maintains arterial partial pressures of CO2 (PaCO2), O2 and pH remarkably constant via ventilatory regulation. It can be divided into two subsystems: a controller (controlling element) and a plant (controlled element). The respiratory operating point (ventilatory or PaCO2 response) is determined by the interplay between the controller (arterial PCO2 [PaCO2] → minute ventilation [VE] relation) and plant (VE → PaCO2 relation) subsystem elements within the respiratory control system. This review outlines the methodology of converting the closed loop of the respiratory control system to an open loop state, then simplifying the controller and plant subsystems, and identifying the input−output relationship using a systems physiological technique (equilibrium diagram method). Changes in central hemodynamics, exercise stimulus, and regular exercise training modify VE and/or PaCO2 levels at rest and during exercise. These respiratory changes can be quantitatively explained by changes in two subsystem elements on the respiratory equilibrium diagram. Using this analysis technique that allows an integrated and quantitative description of the whole respiratory control system will greatly advance the elucidation of pathological conditions manifesting breathing disorders and respiratory regulation during exercise. By repeating thought experiments utilizing this kind of mathematic model and physiological experiments that provide evidence, deeper understanding will be achieved concerning prediction of the behavior of biological systems beyond the physiological range and understanding of the pathophysiology of diseases that are difficult to study by clinical research.

著者

Ayaka Takegami Taishu Kasai Sonoko Mashimo Naruto Yoshida Hitoshi Shiraki

出版者

The Japanese Society of Physical Fitness and Sports Medicine

雑誌

The Journal of Physical Fitness and Sports Medicine (ISSN:21868131)

巻号頁・発行日

vol.11, no.2, pp.117-124, 2022-03-25 (Released:2022-03-14)

参考文献数

35

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This study investigated the relationships between subjective and objective indicators of training load in female handball players. Twelve female handball players (age: 20.1 ± 1.2 years, height: 164.3 ± 4.2 cm, and weight: 61.8 ± 4.1 kg) belonging to the first division of a university league were included in the study. The training load was investigated over a nine-week period of the competition phase. The subjective load indicator was the session rating of perceived exertion (sRPE), and the objective load indicators were total distance, Player Load™, and heart rate-based training load (HRTL). We observed 20.5 ± 2.3 sessions for each player. The sRPE demonstrated significant relationships (p < 0.05) with all objective load indicators, with correlation coefficients r = 0.73 ± 0.09, 0.73 ± 0.08, and 0.75 ± 0.10 for total distance, Player Load™, and HRTL, respectively. All the relationships were very strong (0.7 < r < 0.9). These results reveal the potential validity of sRPE use in handball and suggest that the sRPE is an indicator that reflects the characteristics of both biomechanical and physiological load indicators.

著者

Kana Konishi Tetsuya Kimura Atsushi Yuhaku Toshiyuki Kurihara Masahiro Fujimoto Takafumi Hamaoka Kiyoshi Sanada

出版者

一般社団法人日本体力医学会

雑誌

The Journal of Physical Fitness and Sports Medicine (ISSN:21868131)

巻号頁・発行日

vol.6, no.2, pp.111-117, 2017-03-25 (Released:2017-03-19)

参考文献数

40

被引用文献数

6

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Exercise-induced changes in executive function affect the control of action in a dynamic environment. This study aimed to examine the effect of sustained high-intensity exercise on executive function. Nine healthy male and female participants (age, 21-28 years) completed an exercise session with 65-min treadmill running at 75% VO2max. Executive function was assessed before and after exercise with the Stroop Color and Word Test that included congruent and incongruent conditions. The reaction time and response accuracy of the test were measured, and the task difficulty was controlled by adjusting the stimulus duration so that each participant could maintain at least 80% response accuracy to exclude the effect of a speed–accuracy trade-off. The levels of plasma norepinephrine and adrenocorticotropic hormone were examined. A significant interaction with the reaction time was found (condition × time, P = 0.024), in which the reaction time significantly increased after exercise only in the incongruent condition (P = 0.019). The response accuracy was not significantly different between before and after exercise in both conditions, which indicated that the response accuracy was controlled as intended. The levels of plasma norepinephrine and adrenocorticotropic hormone were significantly increased after exercise (P < 0.05). These results demonstrated that the reaction time in the incongruent condition increased after sustained high-intensity exercise with a cognitive function test with the response accuracy controlled, indicating a decline in executive function. Increased levels of plasma norepinephrine and adrenocorticotropic hormone may contribute, at least in part, to such decline in executive function.

著者

Yujiro Yamanaka Jim Waterhouse

出版者

一般社団法人日本体力医学会

雑誌

The Journal of Physical Fitness and Sports Medicine (ISSN:21868131)

巻号頁・発行日

vol.5, no.4, pp.287-299, 2016-09-25 (Released:2016-10-03)

参考文献数

66

被引用文献数

6

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The human circadian system derives from two distinct circadian oscillators that separately regulate circadian rhythms of body temperature and plasma melatonin, and of the sleep-wake cycle. The oscillator for body temperature and melatonin is the central circadian pacemaker, located in the hypothalamic suprachiasmatic nucleus (SCN), and the oscillator for sleep-wake cycle is another oscillator, located in the brain but outside the SCN. Although bright light is a primary zeitgeber for circadian rhythms, non-photic time cues such as a strict sleep schedule and timed physical exercise act as a non-photic zeitgeber for the sleep-wake cycle under dim light conditions, independent on the SCN circadian pacemaker. Recently, timed physical exercise under bright light has been shown to accelerate re-entrainment of circadian rhythms to an advanced sleep schedule. Physical exercise may enhance the phase-shift of circadian rhythm caused by bright light by changing light perception. In the field of sports medicine and exercise science, adjustment of the circadian rhythm is important to enable elite athletes to take a good sleep and enhance exercise performance, especially after inter-continental travel and jet lag.

著者

Masatoshi Nakamura Tome Ikezoe Satoru Nishishita Hiroki Tanaka Jun Umehara Noriaki Ichihashi

出版者

The Japanese Society of Physical Fitness and Sports Medicine

雑誌

The Journal of Physical Fitness and Sports Medicine (ISSN:21868131)

巻号頁・発行日

vol.8, no.3, pp.113-116, 2019-05-25 (Released:2019-05-18)

参考文献数

24

被引用文献数

9 15

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Static stretching (SS) is widely used to decrease and retain the passive stiffness of the muscle-tendon unit in clinical and athletic settings. It is important to consider the minimum SS duration required to decrease the passive stiffness of the hamstring, from the perspective of injury prevention of the hamstring muscle. The purpose of this study was to investigate the time course of the effect of static stretching (SS) on passive stiffness of the hamstring and to clarify the minimum SS duration required to decrease the passive stiffness. Fifteen healthy males participated in this study. Fifteen healthy and non-athlete male volunteers participated in this study. SS of 60-s session was performed for five sessions with a 30-s rest between sessions. Passive stiffness was measured prior to SS (PRE) and immediately after each SS session to determine the minimum SS duration required to decrease the passive stiffness. The passive stiffness was calculated as the slope of the torque-angle curve corresponding to 50% of the final angle (Nm/°). Passive stiffness after 180, 240, and 300 s of SS was significantly lower than that at PRE. Our results showed that SS for >180 s is recommended to decrease the passive stiffness of the hamstring muscle.

著者

Hisashi Naito Toshinori Yoshihara Ryo Kakigi Noriko Ichinoseki-Sekine Takamasa Tsuzuki

出版者

The Japanese Society of Physical Fitness and Sports Medicine

雑誌

The Journal of Physical Fitness and Sports Medicine (ISSN:21868131)

巻号頁・発行日

vol.1, no.1, pp.125-131, 2012-05-25 (Released:2012-08-22)

参考文献数

61

被引用文献数

9 10

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Many researchers have been interested in the effects of heat stress on skeletal muscle. Recently, it has been demonstrated that heat stress on skeletal muscle results in an increase in muscle protein mass and subsequent muscle hypertrophy, and attenuation of muscle atrophy. Although the cellular mechanism remains unclear, it is thought that heat shock proteins (HSPs), which are highly conserved proteins induced by heat stress, play a major role in these phenomena. However, new insights suggest that heat stress-induced muscle hypertrophy and the prevention of muscle atrophy may be regulated not only by elevated HSP expression but also by multiple signaling pathways associated with protein synthesis and breakdown. Additionally, heat stress seems to cause various changes in other muscle functions. Although further studies are required to reveal the molecular biological mechanisms involved in the heat stress-induced changes in skeletal muscle, heat stress may be a useful tool for increasing muscle mass, attenuating disuse skeletal muscle atrophy, facilitating an early recovery from muscle damage, and improving glucose metabolism. This paper reviews studies of these effects of heat stress on skeletal muscle.

著者

Yuka Watanabe Yuko Miyagoe-Suzuki

出版者

一般社団法人日本体力医学会

雑誌

The Journal of Physical Fitness and Sports Medicine (ISSN:21868131)

巻号頁・発行日

vol.4, no.1, pp.73-82, 2015-03-25 (Released:2015-03-23)

参考文献数

114

被引用文献数

2

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Muscle mass and strength decline with age. When severe, the loss is called sarcopenia. Sarcopenia is drawing attention worldwide, especially in highly aged societies, as a disease that should be treated. At present, we have limited tools to combat sarcopenia (e.g. resistance training and nutritional intervention), but accumulating knowledge of the molecular and cellular mechanisms of sarcopenia is accelerating the development of pharmacological therapies for sarcopenia. Because sarcopenia is a complicated pathological condition caused and modified by many aging-related factors, such as inactivity, loss of motor neurons, poor nutrition, decline of anabolic hormones, chronic inflammation, oxidative stress, impaired stem cell function, and comorbidity, the proposed target molecules or pathways for pharmacological intervention are diverse. Here we review recent progress in drug development with emphasis on small-molecule compound-based therapies and review the literature to identify new therapeutic targets to prevent, delay, or reverse sarcopenia.

著者

Hayao Ozaki Takashi Abe Alan E. Mikesky Akihiro Sakamoto Shuichi Machida Hisashi Naito

出版者

一般社団法人日本体力医学会

雑誌

The Journal of Physical Fitness and Sports Medicine (ISSN:21868131)

巻号頁・発行日

vol.4, no.1, pp.43-51, 2015-03-25 (Released:2015-03-23)

参考文献数

69

被引用文献数

2 13

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This paper reviews the existing literature about muscle hypertrophy resulting from various types of training to document the significance of mechanical and metabolic stresses, and to challenge the conventional ideas of achieving hypertrophy that exclusively rely on high-load resistance training. Low-load resistance training can induce comparable hypertrophy to that of high-load resistance training when each bout or set is performed until lifting failure. This is attributable to the greater exercise volume and metabolic stress achieved with low-load exercise at lifting failure, which, however, results in a prolonged exercise bout. Endurance exercises (walking and cycling) at moderate intensity are also capable of eliciting muscle hypertrophy, but at much slower rates (months rather than weeks) in limited muscle or age groups. Blood flow restriction (BFR) in working muscles, however, accelerates the development of metabolic fatigue, alleviating the time consuming issue associated with low-load or endurance training. These alternative training methods, however, cannot completely replace conventional high-load resistance training, which provides superior strength gain as well as performance improvement even for trained individuals. The alternative approaches, therefore, may be considered for those who are less enthusiastic or under certain medical conditions, or who have limited or no access to proper equipment. However, people should be aware that low-load resistance training or endurance training entails substantial effort and/or discomfort at lifting failure or with BFR. Understanding the advantages and disadvantages of each method will help in assigning the most suitable training program for each client’s goals and needs.

著者

ZhenFei Zou Naoshi Morimoto Miyuki Nakatani Hirotsugu Morinaga Yohei Takai

出版者

The Japanese Society of Physical Fitness and Sports Medicine

雑誌

The Journal of Physical Fitness and Sports Medicine (ISSN:21868131)

巻号頁・発行日

vol.12, no.6, pp.161-167, 2023-11-25 (Released:2023-11-14)

参考文献数

18

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We tested a hypothesis that individuals with low maximal voluntary isometric contraction relative to muscle cross-sectional area (MVC/mCSA) would have greater strength gain compared to those with high MVC/mCSA in an early stage from beginning of isometric training to volitional failure. Male adults (n = 24; 22.4 ± 2.5 years, 174.1 ± 6.5 cm, 75.8 ± 14.1 kg) conducted a 3-week isometric training to volitional failure (60-80% MVC, 2-3 times/week, 3 sets/session) in elbow joint flexion with 90° flexion of each arm. Based on the relationship between MVC and mCSA before the intervention, we assigned 16 arms to the higher group (HIGH), 14 to the lower group (LOW) and 18 to the mean group (MEAN). Before the intervention and at the beginning of every week, we measured MVC (myometer) and muscle thickness of anterior upper arm (ultrasound). The mCSA was derived from muscle thickness. The 3-week isometric training to volitional failure increased MVC in all groups, but the relative change in MVC through the intervention was higher in LOW than in HIGH and MEAN groups. The current findings of this study support the abovementioned hypothesis.

著者

Kazushige Oshita Kaito Imayoshi Mizuki Suzue

出版者

The Japanese Society of Physical Fitness and Sports Medicine

雑誌

The Journal of Physical Fitness and Sports Medicine (ISSN:21868131)

巻号頁・発行日

vol.12, no.3, pp.87-93, 2023-05-25 (Released:2023-05-10)

参考文献数

23

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The present study investigated the effects of wearing a non-woven face mask and performing a calculation task, while walking, on gait pattern, breathlessness, and calculation performance. Twenty-one healthy adult males walked 4.0 km/h and 6.0 km/h on a treadmill with and without wearing a face mask. A calculation task using a smartphone was added to the gait task, and the participants were asked to perform two-digit addition calculation tasks displayed on the screen as quickly and accurately as possible. Heart rate, perceived exercise intensity, breathlessness, and cadence during gait tasks were measured. Although wearing the mask did not significantly affect heart rate or cadence during gait, breathlessness and perceived exercise intensity were significantly increased. When the calculation task was performed during gait, wearing the mask significantly decreased the correct answer rate, although the number of responses was not affected. Wearing the mask therefore reduced the calculation performance during gait. These results suggest that wearing a mask during gait may increase breathlessness and may worsen mental demands such as performing a calculation task, even if it does not affect physiological responses or gait patterns. As walking in daily life requires a variety of cognitive/mental demands, the impact of wearing a mask on the implementation of these demands may need to be considered.

著者

Yasuaki Tamura Hajime Miura Kenichi Deguchi Yuji Hashimoto Junji Deguchi Ayako Murakami Mizuki Ishikawa

出版者

The Japanese Society of Physical Fitness and Sports Medicine

雑誌

The Journal of Physical Fitness and Sports Medicine (ISSN:21868131)

巻号頁・発行日

vol.11, no.4, pp.221-226, 2022-07-25 (Released:2022-07-12)

参考文献数

37

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High-intensity interval training improves the vascular endothelial function better than moderate-intensity continuous training. However, few studies have examined the effects of repetition training consisting of high-intensity exercise, followed by complete rest, on arterial function. We performed this study to investigate the effects of repetition training of high-intensity exercise on the vascular endothelial function determined by flow-mediated vasodilation. Twenty healthy male participants were randomized and stratified into two training groups, one group performed moderate-intensity continuous training (n = 10) while another performed repetition training of high-intensity exercise (n = 10). Both groups exercised 3 times a week for 6 weeks. Before and after each training protocol, the vascular endothelial function of the right brachial artery was assessed by flow-mediated vasodilation. In the moderate-intensity continuous training group, flow-mediated vasodilation changed 9.92 ± 2.45% to 10.58 ± 2.93% (ns). In the repetition training of high-intensity exercise group, flow-mediated vasodilation changed 7.26 ± 1.46% to 8.58 ± 1.22% (p < 0.05). A greater increase in vascular endothelial function was observed in high-intensity repetition training compared to moderate-intensity continuous training. These results suggest the possible effect of repetition training on the prevention of cardiovascular disease.

著者

Shohei Dobashi Chinatsu Aiba Daisuke Ando Masataka Kiuchi Mitsuya Yamakita Katsuhiro Koyama

出版者

The Japanese Society of Physical Fitness and Sports Medicine

雑誌

The Journal of Physical Fitness and Sports Medicine (ISSN:21868131)

巻号頁・発行日

vol.7, no.4, pp.239-245, 2018-07-25 (Released:2018-07-18)

参考文献数

40

被引用文献数

2 2

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Both exercise training and chronic caloric restriction contribute to brain health through enhanced expression of brain-derived neurotrophic factor (BDNF). This study investigated the synergistic effects between 12-week low-intensity exercise training and caloric restriction on hippocampal BDNF expression with redox status in rats. Twenty-six, 7-week-old male Wistar rats were randomly divided into the following 4 groups: (1) sedentary control (Con, n = 7), (2) exercise (Ex, n = 6), (3) caloric restriction (CR, n = 7), and (4) caloric restriction and exercise training (ExCR, n = 6). Although Con and Ex rats were fed ad libitum over time, CR and ExCR rats consumed 40% less food compared to Con rats. Ex and ExCR rats underwent low-intensity treadmill running (30 min/day, 5 days/week). Forty-eight hours after the termination of the 12-week intervention, rats were sacrificed and the hippocampus was quickly dissected for measuring BDNF expression and markers of oxidative stress, including 4-hydroxy-2-nonenal (4-HNE). Hippocampal BDNF expression was significantly increased in Ex compared to Con rats (p = 0.007), whereas the exercise-induced increase in BDNF was completely suppressed by a combination with caloric restriction. Furthermore, we observed a significant relationship between hippocampal BDNF and 4-HNE expression (r = 0.725, p < 0.001). Our findings indicate that exercise training combined with caloric restriction might not have a synergistic effect on hippocampal BDNF expression in young rats. Moreover, exercise-induced oxidative stress can trigger BDNF expression in the hippocampus.

著者

Hiroki Nakata Akito Miura Michiko Yoshie Takatoshi Higuchi Kazutoshi Kudo

出版者

The Japanese Society of Physical Fitness and Sports Medicine

雑誌

The Journal of Physical Fitness and Sports Medicine (ISSN:21868131)

巻号頁・発行日

vol.3, no.4, pp.457-466, 2014-09-25 (Released:2014-10-02)

参考文献数

16

被引用文献数

4 4

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We investigated differences in trunk rotation patterns during baseball batting in eight skilled (collegiate level) players and nine unskilled novices using high-speed video cameras. The maximum angle during the backswing, angle at bat-ball impact, and angular displacement during the forward swing were analyzed for data on upper torso, pelvis, and torso-pelvis interaction (trunk twist) angles. We also noted movement variability in these angles over 10 trials, which was calculated as the standard deviation. The timing of the maximum angle during the backswing and variability was also analyzed. Statistical analysis revealed that angular displacements in the upper torso, pelvis, and torso-pelvis interaction were significantly larger in skilled players than in unskilled novices (p < 0.001, p < 0.001, and p < 0.05, respectively). The timing of the maximum pelvis angle during the backswing was significantly later in skilled players than in unskilled novices (p < 0.05). Movement variability in angular displacement during the forward swing and timing during the backswing were significantly greater in unskilled novices than skilled players. Although many previous studies reported the importance of angular velocity in trunk rotation during baseball batting, our results indicate that angular displacement and movement variability during trunk rotation are also key components for understanding the proficiency of skilled baseball players and unskilled novices.

著者

Fumiya Tanji Yusuke Shirai Toshiki Tsuji Wataru Shimazu Yoshiharu Nabekura

出版者

The Japanese Society of Physical Fitness and Sports Medicine

雑誌

The Journal of Physical Fitness and Sports Medicine (ISSN:21868131)

巻号頁・発行日

vol.6, no.1, pp.41-48, 2017-01-25 (Released:2017-01-21)

参考文献数

43

被引用文献数

8 10

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Running economy (RE), which is evaluated at an exercise intensity below the lactate threshold (LT), is recognized as the most important physiological variable for estimating running performance. However, middle- and long-distance athletes run above LT intensity during their competitive events. This study elucidates the relation between 1,500-m running performance and physiological variables, including RE measured at intensities below and above the LT. The study included 34 male distance runners (1,500-m velocity: 22.2 ± 0.8 km·h−1, equivalent to race times of 4′03″2 ± 8″5). RE was calculated at four running velocities selected to provide intensities of 90%LT and 95%LT below LT (REbLT) and 105%LT and 110%LT above LT (REaLT). RE was determined from aerobic energy metabolism, calculated from oxygen uptake and the respiratory exchange ratio, combined with anaerobic energy metabolism, calculated from the change in blood lactate concentration. Results show that the 1,500-m velocity was not related to maximal oxygen uptake (VO2max) or LT intensity (r = 0.19 and 0.10, respectively). This velocity correlated with both REaLT and REbLT, with the correlation coefficient being higher for REaLT (r = −0.65 and −0.71 vs −0.56 and −0.58). Furthermore, the coefficient of determination for 1,500-m velocity determined from VO2max, LT intensity and REaLT was higher than that determined from VO2max, LT intensity and REbLT (R2 = 0.603 and 0.640 vs 0.415 and 0.543). These results suggest that RE measured at an intensity above LT intensity may be better than other physiological variables for estimating 1,500-m running performance.

著者

Yuta Masuda Issei Kato Kei Nagashima

出版者

The Japanese Society of Physical Fitness and Sports Medicine

雑誌

The Journal of Physical Fitness and Sports Medicine (ISSN:21868131)

巻号頁・発行日

vol.10, no.5, pp.243-253, 2021-09-25 (Released:2021-09-16)

参考文献数

37

被引用文献数

1

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The aim of the present study was to clarify the factors affecting an increase in core body temperature during 40°C water immersion to the subclavian level. Fifteen healthy males were immersed in water for 60 min. Rectal temperature (Trec) and skin temperature (Tsk) at four skin sites were determined. Minute ventilation (VE) was measured, and metabolic rate was determined by indirect calorimetry. Skin blood flow and sweat rate at the forehead were assessed using laser-Doppler flowmetry (%LDFhead) and dew hygrometry (SRhead), respectively. Hot feeling was assessed with a visual analog scale. When Trec reached 39°C or participants reported an extremely hot feeling, the experiment was ceased. Eleven participants were unable to complete the protocol (ten participants due to Trec > 39°C; and one due to excessive hot feeling). Trec increased with immersion period. Mean Tsk was unchanged from 20 min. VE and metabolic rate increased with immersion period. %LDFhead and SRhead increased after immersion and remained unchanged from 15 and 30 min, respectively. Change in Trec from the baseline at 15, 30, and 45 min was correlated to cumulative change in metabolic rate from the baseline at 0-15, 0-30, and 0-45 min. No correlations were observed between change in Trec and cumulative changes in VE, %LDFhead, and SRhead from baseline, hot feeling, body weight and body composition. Water immersion at 40°C induced a large difference in the increase of Trec, in which metabolic responses to heat stress may be involved. The relationship between heat tolerance and change in Trec is different among individuals.

著者

Rumi Kozakai

出版者

The Japanese Society of Physical Fitness and Sports Medicine

雑誌

The Journal of Physical Fitness and Sports Medicine (ISSN:21868131)

巻号頁・発行日

vol.6, no.3, pp.145-149, 2017-05-25 (Released:2017-05-17)

参考文献数

56

被引用文献数

4 16

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Grip strength is a well-known indicator of muscle strength. The trajectories of grip strength with increasing age refer to the aging and development process of muscle strength over one’s life span. The levels of muscle strength needed to perform activities of daily living or to prevent older people from developing disabilities are serious geriatric issues. Grip strength has been shown to decline with aging and to be a predictor of the development of geriatric problems, which suggests the lifelong management of grip strength has great potential for the promotion of healthy aging. The focus of this short review was to examine grip strength as an indicator of geriatric issues and to clarify the role of grip strength in relation to healthy aging.

著者

Hitoshi Wakabayashi Juha Oksa Michael J Tipton

出版者

The Japanese Society of Physical Fitness and Sports Medicine

雑誌

The Journal of Physical Fitness and Sports Medicine (ISSN:21868131)

巻号頁・発行日

vol.4, no.2, pp.177-185, 2015-05-25 (Released:2015-05-28)

参考文献数

100

被引用文献数

13 19

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This review focuses on the suppression of physical performance in a cold environment and the underlying physiological mechanisms. There are many situations where humans have to perform physical activities in a cold environment. Cold environments often limit exercise and working performance by impairing functions such as force production, velocity, power and manual dexterity. A muscle temperature of around 27°C is assumed to be a critical temperature below which maximal voluntary isometric force starts to decrease. The endurance time of submaximal isometric contractions peak at muscle temperatures of 27 to 28°C and decrease rapidly above and below these temperatures. Dynamic exercise performance, especially fast velocity movement, is generally more disturbed by cooling than isometric contractions. Additionally, the effect of cold adaptation on exercise performance, and the potential related mechanisms are summarized here based on a limited number of studies. Since the involuntary muscle contraction of shivering disturbs fine motor control, habituation of shivering, which is an example of cold adaptation, potentially improves exercise performance. Higher hand skin temperatures, induced by greater cold induced vasodilatation after local cold adaptation, could improve manual dexterity. Since there have been few studies testing the effect of cold adaptation on exercise performance in a cold environment, further studies seem warranted.