著者

栗原 俊之 寺田 昌史 伊坂 忠夫

出版者

一般社団法人日本体力医学会

雑誌

体力科学 (ISSN:0039906X)

巻号頁・発行日

vol.69, no.1, pp.102, 2020

著者

西保 岳 姜 熙成 池上 晴夫

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.34, no.5, pp.284-293, 1985-10-01 (Released:2010-09-30)

参考文献数

34

被引用文献数

1 1

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The purpose of this investigation is to evaluate the effects of muscle pump by pedaling exercise on blood circulation and define its properties. Lower body pressurization device equipped with bicycle ergometer was used to provide negative pressure on the lower body of subjects in recumbent position. Seven healthy male collage students volunteered for subjects.Whole experiment for each subjects was divided into control stage (0 mmHg), -20, -40, and -60 mmHg LBNP (lower body negative pressure) stage. Preceeded by resting period, 25, 75, and 125 W exercise in experiment 1, 50 and 100 W exercise in experiment 2 were loaded using bicycle ergometer with revolution of 60 rpm during each stage. Following parameters were determined: HR, SV, Q, and blood pressure.The results obtained were as follows;(1) In resting condition, LBNP caused significant decrease in SV and Q in spite of marked compensatory increase in HR.(2) These effects of LBNP were cancelled in -20 mmHg or mostly cancelled in -40 and -60 mmHg by pedaling exercise of 50 W or more.(3) Effect of muscle pump by pedaling exercise is apparent in light exercise such as 25 or 50 W arriving to a plateau with more intensive load.(4) Muscle pump action by the same exercise condition is more effective under more severe LBNP.(5) Light exercise in LBNP caused decrease in HR, probably because of pressure reflex initiated by restoration of blood pressure.These results leed us to a conclusion that light pedaling exercise produces a powerful pumping action nearly enough to compensate the circulatory disturbance by strong LBNP.

著者

見正 富美子 林達 也 柴田 真志 吉武 康栄 西嶋 泰史 森谷 敏夫

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.45, no.5, pp.519-526, 1996-10-01 (Released:2010-09-30)

参考文献数

30

被引用文献数

6 6

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The present study was designed to examine the effects of aerobic exercise on the change of alpha wave component in electroencephalogram (EEG) and plasma β-endorphin. Exercise consisted of 30-min cycling on an ergometer with the load adjusted to elicit a heart rate rise of 50% between resting and predicted maximal value. The EEG signals and blood samples were obtained before and after 30-min exercise. The EEG signal was digitized at a sampling frequency of 64 Hz and analyzed by means of computer-aided decomposition algorithm and frequency power spectral analyses, respectively. The blood samples were immediately centrifuged for 15-min for quantitative analysis of β-endorphin by means of radioimmunoassay method. Results indicated that β-endorphin was significatly (p<.05) greater after exercise as compared to that of the resting contorol. It was also found that the larger the changes in β-endorphin following exercise, the higher the appearance rate of alpha wave in EEG. There was a positive and significant correlation (r=563, p<0.05) between the increase in alpha wave component and that of the plasma β-endorphin. These results suggest that traquilizer effects of aerobic exercise could be explained, at least in part, by the increase of alpha wave component and plasma β-endorphin which in turn bring about the relaxation effects upon the central nervous system.

著者

髙橋 英幸

出版者

一般社団法人日本体力医学会

雑誌

体力科学 (ISSN:0039906X)

巻号頁・発行日

vol.65, no.1, pp.128, 2016 (Released:2016-01-24)

著者

眞下 苑子 吉田 成仁 森脇 龍 竹上 綾香 藁科 侑希 永井 智 大西 信三 白木 仁

出版者

一般社団法人日本体力医学会

雑誌

体力科学 (ISSN:0039906X)

巻号頁・発行日

vol.70, no.1, pp.79-89, 2021-02-01 (Released:2021-01-13)

参考文献数

41

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The purpose of this study was to investigate the injury patterns and risk factors of injuries among high school handball players in Japan. A total of 1299 (709 male and 590 female) subjects who played in the 2018 Japanese National High School Handball Championship participated in this study. The questionnaire on injury experience was distributed two weeks before the championship and was collected at the representation meeting the day before the championship. The main results were as follows: 1) The subjects (n=625, 48.1%) reported experiences of injuries in the previous year. Female had significantly more suffer injuries than male. 2) The main body parts of injuries were the ankle, knee, and finger in traumatic injuries and the lower leg, lumber spine/lower back, and knee in overuse injuries. The main types of injuries were sprain, ligamentous rupture, and fracture in traumatic injuries and stress fracture, other bone injuries, and lesion of meniscus or cartilage in overuse injuries. The main cause of injuries was “contact with another athlete”. 3) Age, female players, and back players were associated with increased the occurrences of injuries. Goalkeepers were associated with decreased the occurrences of injuries. These results indicated that a high prevalence of injuries in high school handball players, and it is important to take preventive measures based on age, gender, and player position.

著者

坂木 佳壽美

出版者

日本体力医学会

雑誌

体力科学 (ISSN:0039906X)

巻号頁・発行日

vol.50, no.1, pp.105-118, 2001-02-01

参考文献数

48

被引用文献数

1

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腹式呼吸は健康法として, またストレスを緩和させる方法としてその有効性が実証されつつあるが, ヒトには個体差がありストレスに対する反応の現われ方は様々である.<BR>そこで, 心拍変動 (RR間隔変動) から求める自律神経機能評価三指標1) %RR50, 2) CV<SUB>RR</SUB>, 3) E/I<SUB>ratio</SUB>の臥位における平均値を基準値と定義して, 三指標全てが平均値以下のG1 (交感神経活動亢進傾向群) , 平均値以上のG3 (副交感神経活動亢進傾向群) , 三指標の内いずれかが平均値以下, または平均値以上のG2 (中間群) の3群に分別し, 各群の自律神経機能と呼吸循環機能の特徴と腹式呼吸の有効性の違いを検討した.<BR>本研究の対象は女性20名 (48.4±5.5歳) で, 安静臥位 (20分) , 安静坐位 (20分) , 腹式呼吸 (20分: 呼気と吸気の時間の比が2: 1になるように指示した) , 回復 (30分) の計90分間のRR間隔変動 (100個/回) を経時的に測定し (計16回) 、前述の三指標の他にスペクトル解析による四指標 (HF, LF, LF/HF, HF/SUM) とHRを算出, それに対応して血圧値, f, P<SUB>tc</SUB>O<SUB>2</SUB>とP<SUB>tc</SUB>CO<SUB>2</SUB>を測定し, 以下のような結果を得た.<BR>1.安静時臥位において, 自律神経機能評価三指標 (%RR50, CV<SUB>RR</SUB>, E/I<SUB>ratio</SUB>) とHF (高周波成分) はそれぞれ高い正相関 (各P<0.01) を示し, 安静臥位では副交感神経活動が亢進状態にあった事が確認された.<BR>2.群別した3群の特徴と腹式呼吸の影響を以下に示した.<BR>1) G1は群内の個体差が大きく, 特に坐位より臥位において交感神経が緊張傾向を示した.しかし回復では坐位より副交感神経機能優位を示し, その状態が回復30分後まで持続した腹式呼吸の持続効果がみられた.呼吸循環機能は平均値と近似していた.<BR>2) G2は全測定を通してfと血圧は3群中で高値を示した.そして臥位のP<SUB>tc</SUB>O<SUB>2</SUB>値は平均値より低値, P<SUB>tc</SUB>CO<SUB>2</SUB>は高値, HRとfの高値傾向から, 呼吸が浅く速いことが判明した.しかし回復ではHRとfは坐位より低下し, 副交感神経機能は優位になり腹式呼吸の影響が大きく示された.<BR>3) G3は, 臥位において副交感神経が緊張傾向にあり, fと血圧は常時平均値より低く, 血圧とHRとの間に極めて強い関連性がみられた.回復では腹式呼吸後20分以降に副交感神経活動が亢進状態になっている事が認められた.そして他の2群と異なる点は, 回復時のP<SUB>tc</SUB>O<SUB>2</SUB>が腹式呼吸より高く, P<SUB>tc</SUB>COvは逆に低値を示し, より深いG3の腹式呼吸の影響が血液ガスに現われていた.<BR>以上の測定結果から, 安静臥位における自律神経機能三指標の平均値を基準に分別した3群は, それぞれの自律神経機能ならびに呼吸循環機能の基礎レベル, またその両者の関連性にも特徴がみられ, 体位変換や腹式呼吸による反応も各群で異なり, 安静臥位における自律神経の緊張の違いが刺激応答にも反映している事が明示された.しかし, その個体差を前提にしても, 意識的腹式呼吸 (呼気と吸気の時間の比が2: 1) は, 呼吸循環機能を経時的に坐位より緩徐にさせ, 副交感神経活動を亢進状態に導き, その状態を持続させる事は可能であり, その効果が交感神経緊張傾向の人 (G1, G2) に大きく現われたことは特筆すべき事である.<BR>従って, 意識的腹式呼吸は日常生活で生じるストレスを, 自分自身で処理して行くストレス・マネジメントの一方法として活用できる事を確認した.

著者

角田 直也 金久 博昭 福永 哲夫 近藤 正勝 池川 繁樹

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.35, no.4, pp.192-199, 1986-08-01 (Released:2010-12-10)

参考文献数

11

被引用文献数

11 3

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本研究では, スポーツ選手89名 (短距離5名, 長距離10名, バレーボール8名, サッカー12名, ボート22名, スピードスケート16名, 相撲16名) と一般男子14名を対象に, 大腿四頭筋 (MQF) とそれを構成する大腿直筋 (RF) , 外側広筋 (VL) , 内側広筋 (VM) , 中間広筋 (VI) の各断面積における種目差および等尺性脚脚伸展力 (KES) との関係について検討し, 以下の結果を得た.1.MQF断面積は, 相撲 (110.18cm2) が最も高く, ついでスピードスケート (104.09cm2) , バレーボール (99.36cm2) , ボート (96.30cm2) , サッカー (89.92cm2) , 短距離 (86.34cm2) の順であり, 長距離 (73.86cm2) が最も低い値を示した.短距離および長距離を除く他の種目は, 一般人 (75.32cm2) より有意に高い値であった.2.MQFを構成する各断面積は, 相撲, バレーボール, スピードスケートが高い値を示し, 短距離と長距離は, 一般人とほぼ同様な値であった.3.大腿部の全筋断面積に対するMQF断面積の比率は, バレーボール (58.66%) およびボート (57.53%) が高く, サッカー (53.81%) が低い値を示した.しかし, MQF断面積比率は, いずれの種目も一般人との間に有意な差を示さなかった.4.MQF断面積に対する各構成筋群の断面積比率では, サッカーがRFで, スピードスケートがVLで, それぞれ一般人および他の種目より有意に高く, 種目によって特異的に発達する筋が認められた.5.MQF断面積とKESの間には, 0.1%水準で有意な相関関係が認められた.またMQFを構成する各断面積も, KESと0.1%水準で, 有意な相関関係にあり, 断面積が大きな筋ほど, 相関係係数が高くなる傾向が認められた.6.MQF断面積当りのKESは, サッカー (8.97N/cm2) が最も高く, バレーボール (7.10N/cm2) が最も低い値を示した.サッカーのMQF断面積当りのKESは, 一般人 (8.06N/cm2) および長距離 (7.31N/cm2) より5%水準で, バレーポールと相 (7.50N/cm2) より1%水準で, それぞれ有意に高い値であった.サッカーを除く他の種目間の値には, 有意な差は認められなかった.

著者

鎌田 真光

出版者

一般社団法人日本体力医学会

雑誌

体力科学 (ISSN:0039906X)

巻号頁・発行日

vol.69, no.1, pp.95, 2020

著者

李 虎城 向井 直樹 秋本 崇之 河野 一郎

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.51, no.2, pp.175-183, 2002-04-01 (Released:2010-09-30)

参考文献数

37

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[Objective] The purpose of this study was to determine whether icing treatment has an effect on muscle reaction time and functional performance of a sprained ankle. [Methods] Subjects were six persons (healthy group) and six persons who had an acute ankle sprain (patient group) . Anterior talar translation and talar tilt of the six patient group were evaluated by the stress X-ray measure. Ice treatment was applied for 20 minutes. [Results] The following points were clarified : 1) Reaction times of peroneus longus (PL) and peroneus brevis (PB) for the sprained ankle group (SA) were significantly longer than those for the non-sprained ankle group (NA) (p<0.05) . Length of time of standing on one leg with closed eyes for SA was significantly shorter than for NA (p<0.05) . 2) After icing treatment, reaction time of PL for SA tended to be shorter. Furthermore, PB significantly decreased after icing treatment (p<0.05) . Side-steps for SA were significantly increased after icing treatment (p<0.05) . 3) Reaction times of PL and PB for NA significantly increased after icing treatment (p<0.05) . Standing on one leg with closed eyes for NA significantly decreased after icing treatment (p<0.05) . [Conclusion] It was shown that icing treatment of a sprained ankle leads to a shorter muscle reaction time and an increase in the number of side-steps. Therefore, it was concluded that icing treatment of a sprained ankle might be able to improve incapacitated neuromuscular function and functional performance by acute trauma.

著者

寺田 新

出版者

一般社団法人日本体力医学会

雑誌

体力科学 (ISSN:0039906X)

巻号頁・発行日

vol.65, no.1, pp.127, 2016 (Released:2016-01-24)

著者

満園 良一 勝田 茂 金尾 洋治 田渕 健一 永井 純

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.35, no.4, pp.182-191, 1986-08-01 (Released:2010-09-30)

参考文献数

35

被引用文献数

1

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本研究は, 中・長距離ランナー23名 (年齢19~25歳) を対象として, 外側広筋からニードル・バイオプシー法により筋組織を採取し, 骨格筋線維の諸特性を明らかにすること, およびこれら諸特性と, トレッドミル走行により測定された最大, 最大下運動時の有酸素的作業能との関係について検討した.結果は, 以下のように要約される.1) 外側広筋におけるST線維の比率は, %STが61.3%, %area STが63.4%の平均値であり, ST線維寄りの傾向にあった.また, ST・FT線維の平均横断面積は3, 000~13, 000μm2の範囲にあり, ST線維の方がFT線維よりも大きい傾向にあった.2) 外側広筋におけるCapillary supplyは, CDが279±51/mm2, C/F ratioが1.62±0.15, CC (/ST) が5.7±0.9, CC (/FT) が4.5±0.7であり, CCについてはST線維の周りの毛細血管数がFT線維のそれより有意に多かった (p<0.01) .3) 外側広筋におけるSDH活性は, 2.98~12.35μmoles/g/minの範囲にあり, %STおよびCC (/ST) との間にそれぞれr=0.480 (p<0.05) , r=0.640 (p<0.01) の有意な相関関係が認められた.4) トレッドミル走行により測定した有酸素的作業能は, VO2maxが68.5±7.3ml/kg/min (4, 066±329ml/min) , VO2@ATが45.9±5.1ml/kg/min (2, 756±313ml/min) であった.この有酸素的作業能と骨格筋線維の諸特性との関係については, VO2max, VO2@AT (ml/min) と%STとの間にr=0.583, r=0.537 (いずれもp<0.01) , VO2max, VO2@AT (ml/kg/min) とCC (/ST) との間にr=0.534, r=0.430 (いずれもp<0.05) , さらにVO2max, VO2@AT (ml/kg/min) とSDH活性との間にr=0.612 (p<0.01) , r=0.450 (p<0.05) の相関関係がそれぞれ認められた.以上の結果は, 中・長距離ランナーにおいて, ST線維や毛細血管などの構造的特性がSDH活性などの機能的特性を規定する一要因であること, および骨格筋線維の構造的・機能的特性が有酸素的作業能に大きく影響する可能性を示唆している.

著者

大森 肇 八田 秀雄

出版者

一般社団法人日本体力医学会

雑誌

体力科学 (ISSN:0039906X)

巻号頁・発行日

vol.69, no.1, pp.123, 2020

著者

矢野 博己 小栁 えり

出版者

一般社団法人日本体力医学会

雑誌

体力科学 (ISSN:0039906X)

巻号頁・発行日

vol.67, no.1, pp.68, 2018 (Released:2018-01-19)

著者

山本 直史 萩 裕美子 吉武 裕

出版者

一般社団法人日本体力医学会

雑誌

体力科学 (ISSN:0039906X)

巻号頁・発行日

vol.56, no.2, pp.257-268, 2007-04-01 (Released:2007-05-25)

参考文献数

52

被引用文献数

1 6

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The purpose of this study was to examine the effects of walking 10,000 steps/day on the body composition, blood pressure, blood biochemical parameters and physical fitness. Sixty-one women, aged 56.0±5.3 yrs (mean±SD), participated in a hyperlipemia prevention program. The length of the program was 90-min and it was performed one time per week for 3 months. The program consisted of stretching and aerobic exercise (cycle exercise, walking or aerobic rhythmic gymnastics). The participants were asked to walk 10,000 steps/day or more during the program. The number of steps and physical activity (PA) were monitored using a single-axis accelerometer during the program. PA was categorized into three activity levels, namely light (L), moderate (M) and vigorous (V) PA. After 3 months in the program, the participants were divided into two groups according to the average number of steps taken daily during the program : one group (GA) walked more than 10,000 steps/day, while the other (GB) walked below 10,000 steps/day. The time spent in LPA, MPA and VPA in GA were significantly longer than in GB (LPA : 79.4±19.2 min VS 58.2±10.0 min, MPA : 38.5±9.6 min VS 21.6±6.1 min, VPA : 6.3±4.9 min VS 2.6±2.0 min, p<0.001). Decreases in the percent body fat (p<0.001), body fat mass (p<0.001), fasting glucose (p<0.001), hemoglobin A1c (p=0.026), and triglyceride (p=0.036) and an improved performance when balancing on one leg while standing with eyes closed (p=0.027) were found respectively after the program for GA. These findings indicated that GA affected the percent body fat (p=0.036), body fat mass (p=0.040) and fasting glucose (p=0.009). According to a stepwise multiple regression analysis, the time spent in MPA showed a significantly negative correlation with the change in the body fat mass (p=0.025), and the change in the body fat mass showed a significantly positive correlation with the change in the fasting glucose (p<0.001), hemoglobin A1c (p=0.002) and triglyceride (p<0.001). We thus concluded that walking 10,000 steps/day resulted in an increased amount of time spent in MPA, and thus leading to decrease in the amount of body fat. This decrease in body fat is also considered to contribute to improvement in the coronary risk factor profiles.

著者

長谷川 伸 岡田 純一 加藤 清忠

出版者

一般社団法人日本体力医学会

雑誌

体力科学 (ISSN:0039906X)

巻号頁・発行日

vol.57, no.1, pp.131-140, 2008-02-01 (Released:2008-08-06)

参考文献数

23

被引用文献数

1

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The purpose of this study was to investigate sex differences in the muscle volume (MV) of the iliopsoas, psoas major, and iliacus muscles, normalized by fat free mass (FFM), in the elderly. The subjects were 15 males and 15 females 65 years of age or over. Serial transverse 1.5T magnetic images (10 mm slice) of each subject were taken between the 12th thoracic vertebrae and the lesser trochanter. FFM was measured with a bioelectrical impedance analyzer. The mean MV of each muscle on the right and left sides were calculated and used for regression analysis of the relationship between MV and FFM.A significant correlation was observed between MV and FFM of the iliacus in both sexes (p<0.01), but not between the MV and FFM of the psoas major. MV normalized by FFM and cross-sectional area (CSA) normalized by FFM2/3 showed significantly greater values for the psoas major in the males than in the females (p<0.001), but there was no sex difference in the MV or CSA normalized by FFM of the iliacus.These results suggest that elderly males tend to have a greater muscle volume and cross-sectional area of the iliopsoas than elderly females, and that these sex differences are attributable to differences in the psoas major.

著者

森田 恵美子 横山 久代 竹田 良祐 山科 吉弘 河合 英理子 福村 智恵

出版者

一般社団法人日本体力医学会

雑誌

体力科学 (ISSN:0039906X)

巻号頁・発行日

vol.69, no.4, pp.317-325, 2020-08-01 (Released:2020-07-15)

参考文献数

49

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We examined the relationship between masticatory ability and bone mineral density (BMD) and the role of muscle strength in those relationships in 156 female university students. Masticatory ability was assessed using a color-changeable chewing gum method. The BMD of the calcaneus was measured using quantitative ultrasonography and represented by a T-score, the standard deviation (SD) from the mean BMD of young adults. Body composition, grip strength, physical activity level, and daily nutrient intake were also assessed. Osteopenia, defined as the T-score < ‒1.0 SD, was present in 43 participants (27.6%). There was no significant relationship between masticatory ability (ΔE) and T-score in all participants. In participants with normal BMD (T-score ≧ ‒1.0 SD: the normal BMD group), masticatory ability significantly correlated to BMD (r = 0.289, p = 0.002). There was significant correlation between ΔE and grip strength neither in all participants nor in either group, although the grip strength in the normal BMD group was greater than that in the participants with osteopenia (the low BMD group) (p = 0.039). Physical activity level was positively correlated to the total daily energy intake (r = 0.193, p = 0.041) only in the normal BMD group. The present results suggest that masticatory ability is associated with BMD in young females with normal BMD, but the role of muscle strength in those relationships remains unclear. Meanwhile, there was no relationship between masticatory ability and BMD in young individuals with lower BMD.

著者

八田 秀雄

出版者

一般社団法人日本体力医学会

雑誌

体力科学 (ISSN:0039906X)

巻号頁・発行日

vol.65, no.1, pp.125, 2016 (Released:2016-01-24)

著者

横堀 栄 中村 常弘

出版者

一般社団法人日本体力医学会

雑誌

体力科学 (ISSN:0039906X)

巻号頁・発行日

vol.11, no.3, pp.123-129, 1962-11-01 (Released:2010-09-30)

参考文献数

4

著者

星川 佳広 飯田 朝美 村松 正隆 内山 亜希子 中嶋 由晴

出版者

一般社団法人日本体力医学会

雑誌

体力科学 (ISSN:0039906X)

巻号頁・発行日

vol.55, no.2, pp.217-228, 2006-04-01 (Released:2007-05-10)

参考文献数

22

被引用文献数

7 4

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The aim of the study was to measure the cross-sectional area of the psoas major muscle (P-ACSA) in high school athletes and to produce a P-ACSA index independent of body size using an allometric modeling approach to examine the differences in gender and sport specialization. The subjects were 254 female (16.8±0.8 yrs) and 540 male (16.9±0.8 yrs) high-level high school athletes from 17 different sports. Fat-free mass (FFM) was measured by the Bod Pod system (LMI) and P-ACSA was determined by magnetic resonance imaging at the center of the L4-L5 transverse level. Since the power function model fit the data better than a simple linear model in the correlation between FFM and P-ACSA, and the power exponent parameter was almost equal to the theoretically anticipated 2/3 in both genders, the P-ACSA per FFM2/3 as well as the absolute P-ACSA was calculated. Both of the absolute P-ACSA and P-ACSA per FFM2/3 were significantly different according to gender and the sport specialization. While volleyball and badminton players and canoeists showed smaller P-ACSA, in accordance with the previous studies on senior sprinters, high school sprinters also showed predominant development of P-ACSA regardless of gender. These results suggested that regular involvement in sprinting activity could affect the size of the psoas major muscle in high school athletes.

著者

山中 亮 松林 武生 佐伯 徹郎 榎本 靖士 山崎 一彦 杉田 正明

出版者

一般社団法人日本体力医学会

雑誌

体力科学 (ISSN:0039906X)

巻号頁・発行日

vol.65, no.3, pp.307-313, 2016-06-01 (Released:2016-05-14)

参考文献数

24

被引用文献数

1 1

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The purpose of this study was to examine the relationships between running performance and the cross–sectional area of the psoas major, peak oxygen uptake, and running economy in male junior long–distance runners. The subjects were 37 male junior athletes who achieved good records in interscholastic athletic competition during 5 years (2011–2015). Their seasonal best times in a 5,000 m race (5,000m–SB) were 14:04.11 ± 0:07.25 (13:53.64–14:16.15). In a multiple regression analysis, 5,000m–SB was statistical significantly correlated with the cross–sectional area of psoas major (16.0 ± 1.7 cm2) measured on magnetic resonance imaging and peak oxygen uptake (4.25 ± 0.36 l min-1 [76.9 ± 5.8 ml min-1 kg-1]) during a lactate curve test comprising five stages. However, 5,000m–SB was not related to oxygen uptake at the work–load which was less than the load at the lactate threshold estimated by using the lactate curve test results. These results suggest that a high volume of the psoas major, the largest hip–flexor muscle, and peak oxygen uptake are among the important factors for junior long–distance runner performance.