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

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
永見 邦篤 中野 昭一
出版者
The Japanese Society of Physical Fitness and Sports Medicine
雑誌
体力科学 (ISSN:0039906X)
巻号頁・発行日
vol.28, no.2, pp.112-121, 1979-06-01 (Released:2010-09-30)
参考文献数
22
被引用文献数
1

本研究は, ヒトの動作にみられる筋弛緩現象のうち, 拮抗筋の収縮によって主働筋活動を抑制する場合 (PR) と, 収縮している筋のみを弛緩させる (AR) , いわゆる脱力時にみられるものの2つの弛緩動作について, 筋弛緩時間を指標として, その遅速を生じる要因, ならびに生理的意義を検討したものである。動作は, 左右の上肢とも前腕部を回内および回外位とし, 肘関節を90°に固定して, 最大屈腕力の10, 30, 50%の筋力を発揮した後, 筋弛緩を行う方法であった。また, 筋力発揮条件は, 低周波発生装置によってブラウン管面上に示された鋸歯状波および矩形波に追随させる場合と, 検者の合図に従わせるものの3つである。筋電図は, 上腕二頭筋と上腕三頭筋から表面誘導法によって記録した。筋弛緩時間は, 実験装置の一部に取りつけた高感度の歪計で張力減少時を決定し, この時点と上腕二頭筋の棘波状放電の消失時点との差から計測した。その結果1) 筋弛緩時間は, ARよりPRの方が速かった。いずれの動作でも負荷の増加に従って, その時間は遅延した。また, 1例を除いて, 左右, 回内回外位それぞれで有意差が認められなかった。筋力発揮条件による差異は, ARの場合にみられ, 矩形波に追随したときにおいて速くなる傾向を示した。2) 被検者間で比較すると, ARで弛緩時間の速いものは, 弛緩動作後, いずれの筋放電も完全に消失していた。遅いものでは, 微弱な放電が続く傾向にあった。PRの場合, 上腕二頭筋放電の消失から上腕二頭筋放電の開始までの時間の短いものほど, 筋弛緩時間が速い成績を示した。3) AR, PRともに弛緩動作時に, 張力が一過性に増加する現象が認められた。この張力増加の勾配は, 負荷の増加に従って大きくなり, また, PRにおいて大であった。被検者間でみると, 筋弛緩時間の遅いものほど, この勾配が大きくなる傾向にあった。以上の結果から, ARの筋弛緩時間の遅速は, PRに比べて, より上位の中枢に想定される抑制系の疎通ならびに活動の強弱を反映するものと推察された。そして, 拮抗筋の性質およびその活動に関連する神経系の抑制作用に強く依存するPRとは, その抑制機構を異にすることも示唆された。
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

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
大野 政人 野坂 和則
出版者
The Japanese Society of Physical Fitness and Sports Medicine
雑誌
体力科学 (ISSN:0039906X)
巻号頁・発行日
vol.53, no.1, pp.131-139, 2004-02-01 (Released:2010-09-30)
参考文献数
23
被引用文献数
2 3

運動誘発性筋痙攣の要因として, 筋疲労や脱水などが挙げられているが, その発現メカニズムの詳細は明らかでない.そこで本研究では, 筋痙攣の生じやすさを調べる「筋痙攣テスト」を考案し, その妥当性について検証すると共に, それらを用いて, 筋痙攣に対する筋疲労および脱水の影響を明らかにする事を目的とした.20名に対して筋痙攣テストを行った結果, 普段, 筋痙攣が起こりやすい全員に筋痙攣が誘発され, 筋痙攣の経験がほとんど無い者には誘発されなかった.よって, 筋痙攣テストにより筋痙攣の起こりやすさをスクリーニングできると考えられる.100回の膝関節屈曲運動後に, 主働筋である運動肢のハムストリングスで筋痙攣は誘発されにくくなり, 運動肢の足底の筋群では筋痙攣が生じやすくなった.従って, 運動によって筋痙攣の誘発率は高まるが, 筋疲労がその要因である可能性は低いと考えられる.また, 体重の3%に相当する脱水によって, 足底の筋群で筋痙攣が生じやすくなった.脱水が筋痙攣の要因である可能性は高いと考えられるが, その詳細なメカニズムは今後の検討課題である.
著者
TAKAHIRO MUKAIMOTO ILLYOUNG HAN TATSUKI NAKA MAKOTO OHNO
出版者
The Japanese Society of Physical Fitness and Sports Medicine
雑誌
体力科学 (ISSN:0039906X)
巻号頁・発行日
vol.55, no.Supplement, pp.S209-S212, 2006-10-01 (Released:2012-09-27)
参考文献数
16
被引用文献数
2 3

15 healthy elderly adults (68.6±4.5 years old) participated in this study and were chosen at random for either super low-velocity repetition training (SLT : n=7) or general low-velocity repetition training (GLT : n=8). All subjects performed machine training leg work twice a week for 6 months. Training contents of SLT and GLT were programmed as follows : SLT (Method : 4 seconds of lifting and 6 sec of lowering) and GLT (Method : 2 sec of lifting and 2 sec of lowering). Muscular strength testing was adopted during isometric knee extension using Cybex6000, and body composition was measured by DXA method. As a result, increases in peak torque values and 5 sec average torques value were significantly different in both groups, pre- and post-training (p<0.05). However, there was no significant difference between the two groups. Fat mass significantly decreased during post-training in both groups (p<0.05); however, there was no significant difference between the groups. SLT showed that increases in maximum muscular strength and endurance were similar to GLT. Thus, low-intensity and low-velocity repetition training is suggested as an effective method for elderly adults to increase lower limb muscular strength.
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

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

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
今野 道勝 豊田 章
出版者
The Japanese Society of Physical Fitness and Sports Medicine
雑誌
体力科学 (ISSN:0039906X)
巻号頁・発行日
vol.20, no.4, pp.173-180, 1971-12-01 (Released:2010-09-30)
参考文献数
10

I. Aim and MethodThe cause of the stabbing pain in the side during exercise is not definitely known for the physiologist cannot be sure its appearance when he is prepared to study it. Therefore, in order to reveal the cause of this abdominal pain, the authors carried out first an investigation, then, on the basis of the result of the investigation, made attempt to induce the pain in the two series of experiments without any drug, balloon and so on.In the investigation, the questionnares were distributed to the 200 young male athletes to know about their experience of the abdominal pain during exercise and about the relations between the pain and weather, physical condition, kind of exercise and eating-exercise time interval.In the first series of experiments, eight healthy male students have not the history of an alimentary disorder were selected as the subject. Each subject came to the laboratory after fasting for eight and over hours, then they were loaded one of the two intensities of running on a treadmill in accordance with the procedure as showed in Tab. 1.In the second series of experiments, six of the eight subjects of the first series of experiments were selected as the subject for they complained the pain during running which carried out immediately after drinking or eating. Each subject was loaded walking on a treadmill and cycling on a bicycle ergometer in accordance with the procedure as showed in Tab.2. And this cycling requires about the same oxygen cost as the running at 240meters per minute.The test meal was consisted of baked egg (200g), fish ham (50g), raw cabbage (50g) and boild rice, and before the drinking or eating, each subject was advised to take water or boild rice as much as possible.When the subject complained the pain during exercise, the exercise was stopped about one minute later.II. Result and Conclusion.The pain was found 24 cases during running and only one case during cycling. In 72% of these 25 cases, a great deal of abdominal gas and excreta was found, and in 42% of 31 cases which were not found the pain, a great deal of abdominal gas and excreta was also found. Most of regions of the pain were middle and lower abdomen (80%), and specially in the experiments carried out relatively short time after eating, most of regions of the pain were left side abdomen (86%) .As for the time interval between the eating and exercise, the shorter the time interval, the higher rate of the pain was found.In every case, the pain stopped within seven minutes after exercise and any effect on the body was not found.From the result described above, it may conclude that the staple causes of the abdominal pain during exercise are (1) the abdominal gas or excreta is concentrated locally in the stomach or intestin by the movement of the body during exercise and distends the diaphragm or intestin, and (2) the stomach or intestin which is enlarged by the substances is rocked and tossed by the movement of the body during exercise and stimulates physically or chemically (local anaemia) to the mesentery or interior organs and so on.
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

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

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
中山 悌一
出版者
The Japanese Society of Physical Fitness and Sports Medicine
雑誌
体力科学 (ISSN:0039906X)
巻号頁・発行日
vol.53, no.4, pp.443-453, 2004-08-01 (Released:2010-09-30)
参考文献数
39
被引用文献数
3 2

本研究は, 1950年から2002年までの日本人プロ野球選手の身長と体重が, 戦後飛躍的に向上した一般人の体格と比較して如何に推移してきたか, さらに米大リーグ選手との体格の差は縮まりつつあるのかを明らかにする事を目的として遂行され以下の結果を得た.1.1950年の日本人プロ野球選手の平均身長は170.7cmであったが, 2002年には平均180.1cmまで高くなり53年間で9.4cm (5.5%) の成長を見せた.1950年の日本人プロ野球選手の平均体重は65.0kgであったが, 2002年には79.8kgとなり53年間で14.8kg (22.8%) の増加を認めた.さらに1950年の日本人プロ野球選手の平均BMIは22.3であったがその後徐々に大きくなり2002年には24.6となり, 日本のプロ野球選手ががっちりとした体格へと推移していることが明らかとなった.2.身長のポジション別推移では常に投手が一番高かった.この理由として投手は身長が高い方が投球に有利であるいうポジション的特異性に由来しているものと考えられる.体重のポジション別推移は, 1969年から現在まで捕手が一番重くなっている.この結果は捕手は移動距離が少なく, ポジション的役割としてホームベースを死守する役目を担っているために体重が重い方が有利である事に起因するためと推察される.3.一般人の体格は, 戦後急激に向上したことが数多く報告されているが, 日本人プロ野球選手の体格も同様に大きくなり, 身長は日本人一般男子 (24歳) より5.5%から8.6%の範囲で常に高く, 同様1に体重も日本人一般男子 (24歳) より15.9%から27.3%の範囲で常に重かった.このことより, 日本人プロ野球選手は, 同年齢の日本人一般男子より体格的に非常に優れた選手たちによって構成されていることが明らかとなった.日本人プロ野球選手と日本人一般男子 (24歳) の身長と体重の差は, 1950年代に急激に広がったが1960年以降はその差も小さくなる傾向にある.4.日本人プロ野球選手と米大リーグ選手の体格を比較してみると, 1950年代の身長差は11.4cmであったが, 2000年代の身長差は4.9cmとなった.同様に1950年代の体重差は17.7kgであったが, 2000年代の体重差は13.1kgまで縮まり, 日本人プロ野球選手と米大リーグ選手の体格の差は, 確実に縮まりつつあることが確認できた.
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

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
高橋 正人
出版者
The Japanese Society of Physical Fitness and Sports Medicine
雑誌
体力科学 (ISSN:0039906X)
巻号頁・発行日
vol.43, no.1, pp.66-74, 1994-02-01 (Released:2010-09-30)
参考文献数
12
被引用文献数
1 1

I report a case of scalp hair loss and nail destruction as possible side effects of anabolic androgenic steroid (AAS) doping in a Japanese athlete. The patiet, a 27-year-old man, was an amateur bodybuilder who won the championship in a bodybuilding contest. However, he tested positive in a doping test for drostanolone and stanozolol, and was deprived of his championship.In Japan, positive results in doping tests are very rare. The patient suffered from loss of scalp hair and destruction of the nails before the contest. In addition, he presented with hoarseness and soft tumors of the lower extremities. Laboratory data showed hypotestos-onemia caused by AAS doping. However, a hCG test revealed that he still had positive of sex function capacity. Therefore the patients natural course was observed without medical treatment, and the symptoms were resolved within four months after the contest. This is considered to be the first case of nail destruction caused by AAS doping reported in the world.
著者
西薗 秀嗣 中川 功哉 須田 力 斎藤 勝政
出版者
The Japanese Society of Physical Fitness and Sports Medicine
雑誌
体力科学 (ISSN:0039906X)
巻号頁・発行日
vol.33, no.1, pp.17-26, 1983-02-01 (Released:2010-09-30)
参考文献数
20
被引用文献数
5 6 4

アーチェリーのシューティングについて, 日米のトップアーチャー2名並びに技術水準の異なる男子大学生アーチャー15名の上肢, 上肢帯, 体幹筋の筋電図記録, 動作分析を行い, 以下の知見を得た。1) 初心者及び経験5年程度の中級者では, セットアップ, ドローの初期から上肢の放電が著しく, フルドローに入って左右側の筋緊張が不安定な状態でリリースがなされる。これに対してトップアーチャーでは初期から上肢帯, 体幹筋の活動が大きく, フルドローでは左右側で均等な強い筋活動がみられた。さらに, フォロースルーで一定時間, 筋活動が安定して持続し, 合理的な筋の作用がなされていた。2) トップアーチャー2名において, リリースに先行して両側の三角筋肩峰部で筋放電休止期Silent Period (S.P.) が認められ, さらに1名で押し手 (左) 僧帽筋横部でも認められた。3) 大学生アーチャー12名について, 経験年数と成績から上級者, 中級者, 初級者に分け, 三角筋でのS.P.の出現率, 潜時, リリース反応時間について検討した結果, 初級者ではS.P.の出現は2名に認められたが出現率は低く, リリース反応時問は190~230msecと長く, かつ分散している。上級者では全員S.P.の出現があり, 出現率は70~100%と高く, S.P.潜時及びリリース反応時間の平均値はそれぞれ, 115msec, 175msecとなり, しかもばらつきが少ない。4) 引き手 (右) 三角筋のS.P.の出現と同側僧帽筋の活動増強の時期が, 特に上級者群でほぼ一致した。この両筋は神経支配が異なり, リリース動作での拮抗筋と考えられず, リリース動作での一連の主働筋と考えられる。これらのことから, アーチェリーのシューティングという複雑な動作で出現したS.P.は, 長期にわたるトレーニングによる巧緻性獲得過程にみる一つの合理的な神経筋機構であると考えられる。
著者
竹島 伸生 小林 章雄 田中 喜代次 新畑 茂充 渡辺 丈真 鷲見 勝博 鈴木 雅裕 小村 堯 宮原 満男 上田 一博 加藤 孝之
出版者
The Japanese Society of Physical Fitness and Sports Medicine
雑誌
体力科学 (ISSN:0039906X)
巻号頁・発行日
vol.38, no.5, pp.197-207, 1989-10-01 (Released:2010-09-30)
参考文献数
33
被引用文献数
3 1

本研究は, 中高年ランナーに対して自転車エルゴメーター作業を負荷することにより, LTおよびall-out時でのVo2, HR, SBP, DBPを測定し, これらの加齢変化やトレーニング内容などとの関係について検討した.その結果は, 次のように要約できる.1.身長, 体重, %fat, 体格指数は, 年代間で有意な差は認められず, すべての年代のランナーは類似の痩身体型であった.週当りの走行距離時間, 頻度などは個人差が大きいが, 平均値でみると年代間に有意な差は認められなかった.ランナーとしての経験年数も年代間に有意な差は認めちれなかった.しかし, 加齢に伴い走パフォーマンスは著明に低下した.2.年齢とVo2@LTとの間には有意な相関 (r=-0.686) がみられた.しかし, %Vo2max@LTは, 各年代でほぼ同値であり, 年齢との間に一定の関係は認められなかった.3.年齢とHR@LTとの間には有意な相関がみられたが, %HRmax@LTは%Vo2max@LTと同様に年齢とは無関係であった.4.SBP@LT, DBP@LTについては年代間に有意な差は認められず, 年齢との関係は明らかでなかった.5.加齢による変化は, Vo2@LT (0.5ml/kg/min/yr) よりもVo2max (0.7ml/kg/min/yr) の方が大きかった.6.Vo2maxの加齢による変化は, 既報の一般人やランナーと比べて大きかった.しかし, 各年代でのVo2maxは, 一般人に比べ平均で50~60%高く, 例えば70歳代ランナーのVo2maxは一般人の40歳代に相当した.7.Vo2maxとトレーニングの経験年数との間には有意な関係はみられなかったが, ランナーとしてのトレーニング開始年齢とVo2maxとの間には, 有意な相関が認められた.8.HRmaxは, Vo2maxと同様に加齢による低下を示し, 同性同年代の一般人と比べて有意差はみられなかった.9.推定HRmaxと実測したHRmaxとの間には, 有意な相関 (r=0.600) がみられたものの, 個人差が大きく±10拍/分以上の誤差を生じた者が約32%いた.10.SBPmax, DBPmaxは, 年代間で有意な差はみられず, 中高年ランナーにおいては年齢と血圧の関係は明らかでなかった.
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

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

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.
著者
小野 高志 藤井 均
出版者
The Japanese Society of Physical Fitness and Sports Medicine
雑誌
体力科学 (ISSN:0039906X)
巻号頁・発行日
vol.62, no.1, pp.87-94, 2013-02-01 (Released:2013-02-14)
参考文献数
27
被引用文献数
1

Hamstring muscles form a multi-articular muscle group that crosses the hip and knee joints. It has been said that the imbalance in the hamstrings:quadriceps strength ratio (H:Q ratio) due to weaker hamstring muscles results in an increased susceptibility to hamstring strains and anterior cruciate ligament injuries. Four different hamstrings trainings, Hip Lift (HL), Single-leg Deadlift (DL), Leg Curl (LC), and Nordic Hamstrings (NH), were conducted and compared in the effect on conventional H:Q ratio. After the training of two months, significant increase of hip extension torque and H:Q ratios in the hip joint were found in the DL group, and significant increase of knee flexion torque and H:Q ratios in the knee joint were found in the LC group (P < 0.05). As a conclusion, DL and LC training could be practical for hamstrings injury prevention.
著者
Hiroaki Eshima
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.9, no.5, pp.199-204, 2020-09-25 (Released:2020-09-16)
参考文献数
42
被引用文献数
2

Obesity and aging reduce skeletal muscle contractile function, which represents a reduction in muscle quality. Dysfunction of muscle contraction may contribute to a greater risk for diabetes, cardiovascular diseases, and cancer; therefore, the synergistic effects of obesity and aging on muscle function may exacerbate morbidity and mortality. However, evidence directly examining the synergistic effects of obesity and aging on muscle contractile function is lacking and controversial. We recently demonstrated that diet-induced obesity significantly exacerbates contractile dysfunction in aged skeletal muscle. The focus of this review is the effects of obesity on muscle contractile dysfunction in skeletal muscle, particularly during aging.
著者
八十島 崇 木塚 朝博 埜口 博司 白木 仁 向井 直樹 宮永 豊
出版者
The Japanese Society of Physical Fitness and Sports Medicine
雑誌
体力科学 (ISSN:0039906X)
巻号頁・発行日
vol.52, no.5, pp.491-498, 2003-10-01 (Released:2010-09-30)
参考文献数
28
被引用文献数
1 1

The purpose of this study is to identify the effect of position (full can, empty can) and change of angle on the activity of shoulder muscles during scapular plane abduction ; and also to examine its application to exercises used for rehabilitation of shoulder muscles. Seven healthy subjects (23.4±1.4 yr) with normal shoulder function performed scapular plane abduction with external rotation (full can) and scapular plane abduction with internal rotation (empty can) . An electromyogram was recorded with a fine wire intramuscular electrode at the supraspinatus, deltoid anterior, middle, posterior and trapezius upper with bipolar surface. The EMG activity (RMS) of each muscle was normalized by the highest EMG activity (100%RMS) during a maximum manual muscle test for each muscle (%RMS) . The %RMS of each muscle remarkably increased with a change of the angle for empty can, whereas it showed a slight increase with a change of the angle for full can. This finding suggests that the position of full can and empty can in scapular plane abduction affects the function of shoulder muscles. In addition, full can exercise is recommended in order to improve function of the supraspinatus and the muscular activity balance between the supraspinatus and the deltoid. Empty can exercise is applied to sport-specific exercise for rehabilitation of shoulder muscles.