著者
Hirofumi Zempo Mitsuaki Isobe Hisashi Naito
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.25-31, 2017-01-25 (Released:2017-01-21)
参考文献数
91
被引用文献数
1

The mechanism which causes sarcopenia, a loss of muscle mass and strength with aging, remains unclear. Muscle mass is controlled by the net balance between protein synthesis and breakdown; however, net balance differences in the basal state do not contribute to sarcopenia. On the other hand, anabolic resistance, a reduction in muscle protein synthesis in response to protein intake, does seem to be involved in sarcopenia. Muscles which are subject to anabolic resistance do not show incremental blood flow volume during the fed-state. Because the vascular system transports amino acids and other nutrients that are essential for muscle protein synthesis, blood flow volume may be a regulator of anabolic resistance. There is some evidence of a link between blood flow and muscle protein metabolism. In addition, a combination of resistance training and amino acid supplementation promotes a positive net protein balance. Resistance training improves, and detraining reduces blood flow volume; therefore, blood flow volume may be involved as a background mechanism for sarcopenia. Moreover, previous studies have shown that sodium nitroprusside, a vasodilatory nitric oxide donor, enhances muscle protein synthesis. Conversely, angiotensin II, a major vasoconstrictive peptide, induces skeletal muscle protein breakdown. In this review, we discuss a possible role for blood flow in skeletal muscle protein metabolism in elderly adults. The regulation of blood flow may prove to be a beneficial treatment for sarcopenia.
著者
Naoya Takei Kenya Takahashi Katsuyuki Kakinoki Hideo Hatta
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.5, pp.253-259, 2018-09-25 (Released:2018-09-25)
参考文献数
26

Over the past few decades, several studies have been conducted on the relationships between peak blood lactate concentration (PBLC) and exercise performance. However, it is still controversial whether PBLC has a correlation with exercise performance, and if it can be a reliable indicator for energy metabolism during short-term high-intensity exercise. Thus, the purpose of the present study is to establish a new reliable indicator. PBLC isn’t able to reflect individual differences in kinetics of post-exercise blood lactate concentration (e.g. different time point of PBLC). Thus, to reflect the individual differences, we focused on the rate of increase in post-exercise blood lactate concentration (RIBLC). Twenty-two male university track athletes were divided into a sprinter group (S: n = 14) and middle- to long-distance runner group (ML: n = 8). 400-m (meter) time trials and blood samplings were conducted to measure exercise performance (average running velocity) and blood lactate concentration. In the present study, PBLC had no significant correlations with average running velocity in both S and ML. The present study supports previous studies that reported no correlations between PBLC and exercise performance. In contrast, significant correlations between RIBLC and average running velocity were observed in both S and ML (r = 0.69, p < 0.001 and r = 0.93, p < 0.01, respectively). RIBLC was significantly higher in ML than S (p < 0.05). It is assumed that RIBLC indicates lactate transport capacity and plays an important role in 400-m sprinting. Based on these results, RIBLC could be a new indicator for energy metabolism during short-term high-intensity exercise.
著者
Kaito Iwayama Kumpei Tokuyama
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.2, pp.307-316, 2012-07-25 (Released:2012-09-11)
参考文献数
56

Indirect calorimetry with a room-size respiratory chamber provides an ideal setting to monitor energy metabolism for a prolonged period. During the last 10 years, experiments with this method have raised interesting observations such as: 1) exercise intensity has no effect on 24 h fat oxidation, 2) exercise has little, if any, effect on 24 h fat oxidation, and 3) exercise before breakfast increases 24 h fat oxidation. To some of the scientific community and general public, the first two statements may be unacceptable. But it can be factually explained that the impact of exercise on energy metabolism is not confined to the period of physical activity itself, and that fat oxidation remains elevated during the post-exercise period. The third observation seems to be insignificant, but contradicts the second one. It is premature to conclude that exercise has no effect on 24 h fat oxidation.
著者
市橋 則明 吉田 正樹
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.42, no.5, pp.461-464, 1993-10-01 (Released:2010-09-30)
参考文献数
8
被引用文献数
5 4

A study was conducted to determine the minimum quantity of leg exercise required to prevent disuse atrophy of the quadriceps femoris muscle during bed rest. The subjects were 10 normal young university students with a mean age of 21.1 years. First, analysis of rectified filtered electromyography (RFEMG) was performed on the rectus femoris and vastus medialis during walking with cadences of 100 steps/min and 150 steps/min. Then, the effects of straight leg raising (SLR), patella setting (PS), knee extension-flexion in a supine position (KEF) and knee extension in a sitting position (KE) were analysed for each muscle using the same method. Based on the value of RFEMG for each muscle during walking, the repetition number for each exercise was calculated. For the rectus femoris, the repetition number for each exercise corresponding to 10000 steps with a cadence of 100 steps/min was 289 for SLR, 466 for PS, 1255 for LEF and 1663 for KE. For the vastus medialis, the corresponding numbers were 1223, 381, 6367 and 2170, respectively. When the cadence increased to 150 steps/min, the repetition number of each exercise for each muscle also increased. These results indicate that high repetition exercise is recommendable to prevent disuse atrophy of the quadriceps femoris muscle. Therefore, the activity of patients should be increased to stimulate weakened muscles such as the quadriceps femoris during hospitalization.
著者
木越 清信 尾縣 貢 田内 健二 大山 卞 圭悟 高松 薫
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.2, pp.167-178, 2003-04-01 (Released:2010-12-10)
参考文献数
16
被引用文献数
2 3

本研究の目的は, 5秒間の全力ペダリング運動中における座位姿勢の変化が下肢筋群の筋活動および最大パワーに及ぼす影響を明らかにすることであった.被験者には, 大学陸上競技部に所属する男性10名 (21.5±1.9yrs, 178.8±4.7cm, 71.0±5.6kg) を用い, シートの高さを変化させた3種類 (High, MiddleおよびLow) の試技条件下で, それぞれ5秒間のペダリング運動を体重×0.1kpの負荷で行わせた.主な結果は以下の通りである.1.3回転の最大パワーは, HighがLowと比較して有意に高値を示した.2.骨盤傾斜角度は, HighおよびMiddleがLowと比較して有意に高値を示した.3.膝関節最大伸展角度および屈曲角度は, High, MiddleおよびLowの川頁に有意に高値を示した.4.脊柱起立筋および大腿二頭筋におけるmEMGは, HighがLowと比較して有意に高値を示した.5.Highにおいては, 3回転の最大パワーと大殿筋におけるmEMGとの間に有意な正の相関関係が認められた.また, 3回転の最大パワーと大腿二頭筋および外側広筋におけるmEMGとの間に正の相関傾向が認められた.以上の結果から, 5秒間の全力ペダリング運動において, シート高の変化による座位姿勢変化は下肢筋群, 特に股関節伸展筋群の筋張力および最大パワーに影響を及ぼす可能性があることが示唆された.
著者
小川 新吉 古田 善伯 山本 恵三 永井 信雄
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.22, no.2, pp.45-55, 1973-06-01 (Released:2010-09-30)
参考文献数
24
被引用文献数
2 1

巨大な体格, 豪力の持ち主であると考えられている現役上位力士) (関取) の形態, 機能の測定および調査を行ない, 種々なる検討を試みた。形態的な測定1.関取の平均身長は180.2cmと, 日本人としてはずばぬけて大柄な集団であるが, スポーツ選手の大型化を考えるとき, 特筆すべき特徴とは考えられない。2.体重は平均122.2kgと超重量級で, ローレル指数も平均210.5と異常に近い充実度を示し, この超肥満体に力士の特徴がみられる。身体の軟組織に富む周囲径, 特に腰囲は, 114.9cm, 臀囲は115.7cmと著しく大きく, 皮脂厚 (3部位の合計) も109.9mmと驚くべき肥厚を示し, 力士の体型の特徴は皮脂厚の異常なまでの発達にあることがわかる。機能の測定3.背筋力の平均は181kg, 握力左右平均47.9kgと予想したほど大きくなく, オリンピックの重量挙や投擲選手以下である。筋力の測定方法等に問題があるにしても, 筋力は形態に比べ予想外に発達していないと考えられる。5.垂直とび47.9cm, サイド・ステップ35.1回, 腕立屈伸21.4回と, 体重が負荷となるテストでは体重の影響が問題となり, スポーツ選手としては著しく小さい。6.しかし, 身体の柔軟性や全身反応時間等は肥満体にもかかわらず, さして劣っていない。7.被検力士の平均肺活量は4918.6mlで, 巨体の割には小さい。8.ステップ・テストの評点は平均49.4, 体重増が負担となり, 同年令成人より著しく劣っている。総体して, 形態の発達に比べて, 呼吸循環器系機能の発達が明らかにアンバランスになっていると考えられる。力士の発育・発連9.一部関取の形態につき, 過去4年間の測定結果を追跡調査した結果では, 身長の伸びはほとんどみられないが, 体重, 胸囲の発達は著しく, 特に体重では6~29kgの著明な増大がみられた。10.上位と下位の力士を比較すると, 上位力士は形態, 特に体重, 周囲径が優れており, 機能面では上位と下位の間にそれほど著明な差違は認められない。したがって, 相撲競技では, 形態の大小が勝負に大きく関与していると考えられる。11.以上の結果を総括してみると, 力士は形態の発達には著しい特徴が認められるが, 機能面では, 他種目の一流スポーツ選手と比較し, 伸びが著しく劣っている。これらについては, 伝統的な練習方法や稽古, 生活様式等に考慮すべき問題があると考えられる。謝辞: 本研究は文部省の特定科学研究費, IBP.HA班の研究助成金をえて実施されたことを銘記しておく。なお, 本研究について, 多大の理解と好意を賜った日本相撲協会の武蔵川理事長, 故秀の山監事, さらに直接御協力を願った各部屋の親方, 責任者, 関取衆に感謝の意を表するものである。
著者
Kenta Yamamoto
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.1-5, 2017-01-25 (Released:2017-01-21)
参考文献数
33
被引用文献数
1 1

Most Japanese people have had their flexibility tested in childhood physical education classes. Recent studies may provide a retrospective answer as to why those measurements may be important. Flexibility is one of the components of physical fitness along with cardiorespiratory fitness and muscular strength. Although flexibility was originally assumed to correlate with other aspects of physical fitness, recent studies demonstrate that a less flexible body indicates arterial stiffening. Arterial stiffness has been identified as an independent risk factor for mortality and cardiovascular disorders. Therefore, there is a possibility that flexibility is a novel fitness indicator related to cardiovascular disease, which can be easily evaluated over all ages and in any area (e.g., medical check-up). Now, flexibility may no longer be simply viewed as important just for optimizing functional movement in daily life and/or reducing the risk of injury. This article reviews the recent findings on the relationship between flexibility and arterial stiffness, emphasizing “flexibility and arterial stiffness”, “genetics and flexibility”, “stretching and arterial stiffness”, and “flexibility and blood pressure”.
著者
平井 雄介 田畑 泉
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.495-502, 1996-10-01 (Released:2010-09-30)
参考文献数
23
被引用文献数
2 3

This study examined the effects of (1) an intermittent training using a mechanically braked cycle ergometer and (2) resistance training using free weight on the maximal oxygen deficit and VO2max. For the first 6 weeks, six subjects trained using an intermittent training protocol five days per week. The exhaustive intermittent training consisted of seven to eight sets of 20 s exercise at anintensity of about 170% of VO2max with a 10 s rest between each bout. After the training, the maximal oxygen deficit increased significantly from 64.3±5.0 ml⋅kg-1 to 75.1±5.7 ml⋅kg-1 (p<0.01), while VO2max increased from 52.0±2.7 ml⋅kg-1⋅min-1 to 57.6±2.9 ml⋅kg-1⋅min-1 (p<0.05) . For the following 6 weeks, the subjects used the same intermittent training for 3 days per week and a resistance training for the other 3 days per week. The resistance training consisted of (1) 4 sets of 12 bouts of squat and leg curl exercise at 12 repetition maximum (RM) . (2) 2 sets of maximal bouts of the same exercise with a load of 90%, 80%, and 70% of 1 RM. After the training period, the maximal oxygen deficit increased further to the value of 86.8±5.9 ml⋅kg-1which was significantly higher than the value attained at the end of the intermittent training. On the other hand, VO2max did not increase significantly from the value observed at the end of the 6 weeks of intermittent training. Body weight was not significantly changed throughout the 12-week training period. Maximal circumference of the thigh did not changed during the first 6-week of the intermittent training period (pre-training: 57.1±1.2 cm, after 6-week training: 57.3±1.1 cm), while it increased significantly after the last 6-week combined training (59.0±0.8 cm, p<0.05) . In conclusion, this study showed that (1) high intensity intermittent training improves both the anaerobic and aerobic energy supplying systems, (2) additional resistance training with the intermittent training further increases the anaerobic energy supplying system, probably through increased muscle mass.
著者
久野 譜也 村上 晴香 馬場 紫乃 金 俊東 上岡 方士
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.Supplement, pp.17-29, 2003-08-01 (Released:2010-09-30)
参考文献数
36
被引用文献数
9 5

The ability to walk is just as important for the elderly as it is for young people. In fact, in the elderly, decreased mobility limits function in daily life and can lead to more serious situations (e.g., becoming bedridden) . The elderly population has increased over the last decade, and many researchers have studied the mobility of the elderly. However, the focus of most studies has been to facilitate recovery of bedridden individuals and prevent the elderly from becoming bedridden, and particularly to prevent fall-induced fractures, which often cause the elderly to become bedridden. However, about 70-80% of the elderly population do not require care, and it is necessary to conduct research on the maintenance of activities of daily living to make it possible for the elderly to work or volunteer. From this perspective, mobility is an important physical factor. Mobility is dependent on muscle activity and it has long been known that aging reduces muscle mass. Therefore, it is feasible to assume that reduced muscle mass leads to decreased ability to walk, and we have proven that there is a close correlation between the two. When presenting the idea of strength training to the elderly, it is appropriate to focus on the maintenance and improvement of mobility, not on the training itself. The results of our research can be summarized as follows:Muscle mass decreases with age, with the legs being affected to a greater degree than the arms. Moreover, muscle atrophy is dependent on weakening of muscle fibers, especially fast-twitch (Type II) fibers. Reduced lower limb muscle mass increases the risk of falling and can decrease walking ability to a degree that can affect daily living activities.In order to improve reduced muscle mass in aging, it is important to use an exercise program that is designed to strengthen fast-twitch fibers, which can be followed even by the elderly. Since walking therapy mostly mobilizes slow twitch fibers, it is not effective in preventing and improving muscle atrophy. It is important to have an exercise program that is designed to mobilize fast-twitch fibers.
著者
水田 拓道 植屋 清見 日丸 哲也 永田 晟 山本 高司
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.24, no.3, pp.101-107, 1975-09-01 (Released:2010-09-30)
参考文献数
8

目的に応じたサウナ入浴をするための一つの条件として, サウナ入浴時間が生体におよぼす影響というかたちで, 主に運動機能的な面からサウナ入浴前後, および入浴中の変化について比較検討した。本実験の結果からサウナの効果的利用法について次のような示唆が得られた。1.アンケート調査の結果, サウナ入浴時間においては5分単位の入浴を繰返している者が最とも多く60%余りをしめていた。また, 95%の者がなんらかの形で冷水浴を併用していた。2.全身反応時間, 膝蓋腱反射閾値, 垂直跳びにおけるジャンプパワー等, 筋神経系の関係する機能においては, 5分入浴, 1分冷水浴で3回繰返し入浴法が, 入浴前に比べてよい成績を示し効果的であることがわかった。このことから, 経験的に得た5分単位の入浴法が, 疲労回復, 気分転換等に効果的であることが裏付けられた。3.血圧, 心拍数, 皮膚温の変化には設定パターンによる著明な差異は認められなかった。しかし, いずれのパターンにおいても循環機能への有効な剌激として考察され, 長期にわたる利用によって環境温の変化に対する適応能を高める効果が期待される。4.サウナ入浴中の酸素摂取量は安静時に比して, パターン (1) が23.2%, パターン (2) が31.6%れぞれ増加した。エネルギー代謝促進の面からは少し長い入浴時間が必要と考えられる。
著者
岩原 文彦 伊藤 雅充 浅見 俊雄
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.499-511, 2003-10-01 (Released:2010-09-30)
参考文献数
36
被引用文献数
1 3

The purpose of this study was to examine the effect of active recovery between two strenuous anaerobic exercises separated by a short time interval. Eight healthy adult male volunteers (age: 24.8±1.8 yrs, height: 170.6±2.5 cm, weight : 70.1 ±2.5 kg) underwent five exercise sessions. Each session consisted of a warm-up, the first anaerobic exercise test (40 sec of exhaustive cycle ergometer exercise), a 30 min inactive (seated) or active recovery period, and a second anaerobic exercise test. During the active recovery period, subjects executed one of four different intensity pedaling tests (60, 80, 100, 120% of predetermined lactate threshold intensity) for 10 min. There were no significant differences in mean power and peak blood lactate concentration among sessions during the first anaerobic exercise test. Significant differences were found in the blood lactate concentration among sessions during the second anaerobic exercise test, and significant differences were found in mean power for the second anaerobic exercise. Optimal intensity related to the blood lactate removal rate was 83.3±7.1%LT, and that related to the working capacity recovery rate was 68.3±11.8%LT.From these results, concerning blood lactate removal rate, it was suggested that between 80%LT and 100%LT was an effective intensity. As for performance, the effective intensity was less than 100%LT.
著者
大島 秀武 志賀 利一 森谷 敏夫 桝田 出 林 達也 中尾 一和
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.3, pp.295-303, 2003-06-01 (Released:2010-09-30)
参考文献数
34
被引用文献数
1 1

The purpose of the present study was to develop a new method that enables individualized determination of the optimal exercise intensity for health promotion. Our study was based on the following observations : (1) physical activity at ventilatory threshold (VT) has been useful for enhancing physical fitness and even improving medical conditions such as heart failure, hypertension and diabetes, (2) exercise intensity at VT is characterized by suppressed vagal activity, and (3) vagal activity can be evaluated by analyzing heart rate variability (HRV) . In the first study we defined a criteria for determining the exercise intensity corresponding to VT using HRV analysis (heart rate variability threshold, THRV) . In 16 normal subjects, a time series of ECG RR interval were recorded and the means of the sum of the squared differences in successive RR intervals (MSSDs) were calcu-lated during a ramp exercise test with a cycle ergometer. Based on the values of MSSD and the dif-ferences in successive MSSDs (ΔMSSD) at the intensity of VT, we defined the criteria of THRV as follows : MSSD<25 msec2and ΔMSSD<6 msec2. Another exercise test with a cycle ergo-meter was performed to evaluate the relationship between THRV and VT in 63 normal subjects. Heart rate (HR) and oxygen uptake (VO2/wt) at THRV were 111.8±13.2 beats/min and 15.2±4.4 ml/kg/min, and HR and VO2/wt at VT were 116.2±11.6beats/min and 16.5±3.7ml/kg/min, respectively. There was a significant correlation between THRV and VT (HR : r=0.82, p<0.001, VO2/wt : r=0.88, p< 0.001) . Thus, THRV and VT provided almost identical exercise intensities. As a result, we propose that, similar to VT, THRV can be used as an indicator of the optimal exercise intensity suitable for health promotion in normal subjects.
著者
Hiroaki Eshima David C Poole Yutaka Kano
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.205-211, 2018-07-25 (Released:2018-07-18)
参考文献数
57
被引用文献数
1

In skeletal muscle, resting cytosolic Ca2+ concentration ([Ca2+]cyto) homeostasis is exquisitely regulated by Ca2+ transport across the sarcolemmal, mitochondrial and sarcoplasmic reticulum (SR) membranes. Specifically, skeletal muscle contractile function is critically dependent on effective SR Ca2+ handling. However, more recent studies have revealed that mitochondria are essentially involved in [Ca2+]cyto homeostasis during and following muscle contractions. We recently provided substantial support for the mitochondria as a major site for Ca2+ sequestration in skeletal muscle during recovery from fatiguing tetanic contractions under in vivo conditions. This review provides an overview of the role of skeletal muscle mitochondria in [Ca2+]cyto regulation in vivo during and following muscle contractions.
著者
呉 堅 山川 純 田畑 泉 吉武 裕 樋口 満
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.49, no.5, pp.543-548, 2000-10-01 (Released:2010-09-30)
参考文献数
20
被引用文献数
4 3

本研究では閉経後女性を対象にして, 2年間の水泳運動が骨量減少に対し抑制効果をもつか否かを調査した.本研究には22名の水泳実施者 (平均年齢59.5歳) と19名の対照者 (平均年齢59.3歳) が参加した.水泳群は1回1時間の水泳運動を週平均1.5回行った.骨密度は腰椎 (第2~第4椎骨) と大腿骨頸部近位部 (大腿骨頸部, 大転子部とワーズ三角部) を二重エネルギーX線吸収法 (DXA) により測定した.また脚伸展パワーは脚伸展パワー測定装置を用いて評価した.測定はベースライン, 1年と2年後に行った.身長, 体重, カルシウム摂取量および日常の身体活動状況はベースラインにおいて二群間に差がなく, 2年間における変化も小さかった.脚伸展パワーにおいては, 水泳群にのみ1年と2年後に有意な増加があった.水泳群では2年間で大腿骨頸部, 大転子部とワーズ三角部の骨密度にそれぞれ4.4%, 5.7%と3.4%の増加がみられた.これに対して, 対照群では三ヶ所の骨密度の変化はそれぞれ-0.2%, 1.0%と-1.4%であった.これら3部位の骨密度の変化率を2群間で比較すると有意差が認められた.しかし, 水泳群の腰椎の骨密度は対照群と同様に減少を示し, 変化率に関して対照群と差がなかった.これらの結果は, 閉経後女性において2年間の水泳運動が大腿骨近位部の骨密度および脚伸展パワーに有益な影響を及ぼすことを示唆している.
著者
湯浅 景元 福永 哲夫
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.36, no.1, pp.36-41, 1987-02-01 (Released:2010-09-30)
参考文献数
21
被引用文献数
2

全身にわたる皮下脂肪厚を測定し, その分布パターンを明らかにした研究は今のところみられていない.本研究では, 2名の成人男子を対象にして, 超音波診断装置 (Bモードlinearタイプ) を用いてほぼ全身の皮下脂肪厚を測定し, その分布パターンを明らかにすることにした.本研究によって得られた結果は次のようであった.1) 体幹で皮下脂肪が厚い箇所は, 臍を中心とした腹部中央と側腹から腰部外側にかけての部分であった.2) 体幹で皮下脂肪が薄い箇所は, 胸部上方の部分であった.3) 体肢では大腿や上腕のように中枢に近いところにある体節で, かつ中枢に近づくほど皮下脂肪は厚かった.4) 以上のことから, 体幹では皮下脂肪厚が幅広く分布しているのに対して, 体肢ではほぼ均一に分布する傾向のみられることが示唆できた.
著者
西保 岳 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.3, pp.167-175, 1985-06-01 (Released:2010-09-30)
参考文献数
27
被引用文献数
2 1

The purpose of this study is to evaluate the effects of muscle pump of pedaling exercise on blood circulation. Lower body pressurization device was used to provide negative pressure and positive pressure on the lower body of subjects in recumbent position. This device is also equipped with bicycle ergometer in it. Five healthy male college students volunteered for subjects.Whole experiment for each subject was divided into pre-control stage (0 mmHg), LBPP (lower body positive pressure) stage (+40mmHg), LBNP (lower body negative pressure) stage (-40 mmHg) and post-control stage (0 mrHg) . 50 (watt) exercise and 100 (watt) exercise preceded by resting period were loaded during each stage and following parameters were determined: ECG, phonocardiogram, carotic pulse wave, VO2, cardiac output, and blood pressure. Pre-ejection period index (PEPi), Left ventricular ejection time index (LVETi), PEP/LVET and stroke volume (SV) were calculated from the recorded data.Results suggested following conclusions:1) In rest condition, LBNP caused marked increase in HR, PEPi, and PEP/LVET and remarkable decrease in Q, SV, and LVETi. These findings indicate that LBNP affects venous return and exaggerates venous pooling in lower body.2) It was shown that muscle pump of pedaling exercise counteracts the effects of LBNP and the findings mentioned above were largely abolished by pedaling exercise of 100 (watt) .3) LBPP caused no apparent change in the studied parameters except blood pressure. Blood pressure increased by LBPP probably because of rising in total peripheral resistance.
著者
久保 啓太郎 川上 泰雄 金久 博昭 福永 哲夫
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.48, no.5, pp.597-605, 1999-10-01 (Released:2010-09-30)
参考文献数
32
被引用文献数
4

The purpose of this study was to investigate the viscoelastic properties of tendon structures in humans. Elongation of the tendon and aponeurosis of medial gastrocnemius muscle (MG) was directly measured by ultrasonography, while subjects (N=12) performed ramp isometric plantar flexion up to the voluntary maximum, followed by a ramp relaxation. The relationship between estimated muscle force (Ff) and tendon elongation (dL) was fitted to a linear regression, the slope of which was defined as stiffness of the tendon structures. The hysteresis was calculated as the ratio of the area within the Ff-dL loop (elastic energy dissipated) to the area beneath the load portion of the curve (elastic energy input) . The resulting Ff-dL relationship was non-linear in form, as previously reported on animal and human tendons in vitro. The mean stiffness was 24.0±5.6 N/mm. However, there was a considerable inter-subject variability (15.8 to 36.8 N/mm) . The Young's modulus, i. e., the slope of the stress-strain curve, was 280 MPa, which tended to be lower than the previously reported values for human tendons. It was also found that the strain of the tendon structures was homogeneously distributed along its length. The mean hysteresis (energy dissipation) was 23.4±12.4%. However, again there was a considerable inter-subject variability (8.7 to 39.3%) . The present results indicated that the tendon structures of human MG was considerably compliant and its hysteresis was in accordance with previously reported values.
著者
木村 直人 勝村 俊仁 浜岡 隆文 下光 輝一
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.47, no.5, pp.549-560, 1998-10-01 (Released:2010-09-30)
参考文献数
18
被引用文献数
2 2

本研究の目的は, 磁気共鳴分光法 (31P-MRS) と近赤外分光法 (NIRS) とを用いて, 等尺性運動負荷時に見られる局所的な筋疲労, 特に運動強度の違いが筋疲労の程度や筋持久力 (持続時間) に及ぼす影響を細胞内の代謝および酸素動態の面から観察し, さらに各負荷強度の持続時間.どの関連について検討を加え, 以下の結果を得た.1) 各相対強度での持続時間は50%MVCで95.3±13.6秒, 30%MVCで209±41.9秒であり, また低強度の10%MVCでは963±236秒と, 50%MVC時の10倍であった.2) 運動中の各測定項目の変動をみると, 運動開始時においてPCrの低下及びPi (H2PO4-) の上昇が見られた.細胞内pHは運動開始40秒 (50%MVC) ~347秒 (10%MVC) まで安静時レベル (-6.95pHunit) 維持したものの, それ以降'低下を示した.また各測定項目 (pH低下率及びH2PO4-増加率) とも強度の上昇に伴いその変化の程度は増大を示した.3) 筋内の酸素化レベルは, 全ての強度において運動開始時直後から直線的に低下を示した.しかしながらその後の変化は各強度間で異なり, 10%, 30%MVCではその後上昇し一定レベルを維持した.一方50%MVCではさらに低下し, 平均値において10%を下回っていた.4) 各相対強度におけるpH低下率及びH2PO4-増加率と持続時間との間には, いずれも負の相関関係が認められた.pH低下率と持続時間との問にはr=-0.578~-0.871の相関係数が得られ, 10%, 30%MVCではそれぞれ有意 (P<0.05) であった.また, H2PO4-増加率との間にはr=-0.370~-0.740の相関係数が得られた.本研究の結果から, 最大下の等尺性運動時における筋持久力 (持続時間) には, 筋興奮・収縮連関やエネルギー供給系に対して直接あるいは間接的に関与する細胞内pHの低下率が重要な因子であることが示唆された.
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 2

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
Erik van der Graaff Marco (MJM) Hoozemans Martijn Nijhoff Michael Davidson Merel Hoezen Dirkjan (HEJ) Veeger
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.5, pp.269-277, 2018-09-25 (Released:2018-09-25)
参考文献数
31

The objective of the present study was to examine the magnitude and timing of peak pelvis and thorax rotations in achieving high throwing velocities in pitching fastballs. During the preseason (Test 1 or T1) and four months later (Test 2 or T2), kinematic analysis was performed on eight elite youth pitchers throwing fastballs. Peak rotation velocities of the pelvis and thorax were determined and separation time, defined as the time between the maximal rotation velocities of the pelvis and thorax, was calculated. Peak thorax rotation velocity was not associated with throwing velocity. However, separation time appeared to be significantly and positively associated with throwing velocity. Also, the changes in separation time from T1 to T2 were significantly and positively associated with the observed increase in throwing velocity from T1 to T2. There was no significant association between the changes in pelvis or thorax peak rotation velocities from T1 to T2 and the change in throwing velocity. Results indicate that the relative timing of pelvis and thorax peak rotation velocity in pitching fastballs in baseball is likely to be a determinant of throwing velocity in skilled pitchers.