KAKENHI (Grants-in-Aid for Scientific Research) -
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Development of a screening test to predict acute mountain sickness
Grant number：26560349 2014.4 - 2017.3
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research Grant-in-Aid for Challenging Exploratory Research
Ishida Koji, SHIMAOKA Kiyoshi, OKAZAKI Kazunobu, YAMAUCHI Koun, ITO Yuka, GOTO Kanako, ITO Hatsue, SHIMIZU Kaori, CHO Rogyoku, SHIMAOKA Kiyoshi, OKAZAKI Kazunobu, YAMAUCHI Koun, ITO Yuka, GOTO Kanako, ITO Hatsue, SHIMIZU Kaori, CHO Rogyoku
Authorship：Coinvestigator(s)
In order to develop a screening test to predict who is more likely to suffer from acute mountain sickness (AMS), we examined the cardio-respiratory responses to acute and gradual (1%/min) decrease in inspired oxygen content (12-13%) during middle intensity (35-40%max) exercise at sea level and compared these between the subjects who had suffered and not suffered from AMS at high altitude. We recruited two subjects’ group, one was the university students who had climbed the same high mountain (3000m) and the other was the middle-aged and elderly who have well experienced in high mountains above 2500m. The results suggested that we had better adopt the gradual hypoxic protocol based on subjects’ comfort and safety, and that people whose arterial oxygen saturation falls rapidly and below 75% during hypoxic exercise, or whose minute ventilation and end-tidal CO2 partial pressure at each stage show lower and higher value respectively should be susceptible to AMS at high altitude.
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低酸素環境を利用した呼吸筋トレーニングの開発と持久的パフォーマンスへの効果
Grant number： 26560348 2014.4 - 2017.3
科学研究費補助金
片山敬章
Authorship：Principal investigator
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Effect of food, time, exercise type and intensity on exhaled acetone during exercise
Grant number：25350812 2013.4 - 2016.3
Nagamine Koichiro
Authorship：Coinvestigator(s)
Acetone is produced in lipolysis, and exhausted with exhaled air and urine. Therefore, acetone contained in the exhaled air is expected to be an indicator of lipolysis in our body. The purpose of this study was to examine the effect of various factors such as meal intake on the expired acetone and blood components during and after exercise by several exercise experiments.
In all conditions, expired acetone significantly increased during or after exercise compared to before exercise. Judging from variations in blood components, lipolysis and production of acetone in their bodies were promoted by exercise. However, the differences about variation in expired acetone were observed by several factors such as meal after exercise, exercise intensity, combination of different types of exercise.
In conclusion, acetone contained in the exhaled air might be useful as the indicator of lipolysis, if we adequately consider the conditions about exercise and meal. -
A developmental and practical study of the tandem-bicycle ergometer
Grant number：24500686 2012.4 - 2015.3
ONODERA Sho
Authorship：Coinvestigator(s)
We developed the tandem-bicycle ergometer. It verified that cardiorespiratory responses to submaximal exercise are the same between front and rear saddles. Thus it is clear that the tandem-bicycle ergometer has the same function as between front and rear saddles.
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Effect of exercise habit on cardiovascular and cerebral blood flow regulations: a fundamental research for preventing brain disease
Grant number：24300237 2012.4 - 2015.3
OGOH Shigehiko
Authorship：Coinvestigator(s)
In our country, it has been reported that 10% of elderly who is more than 65 years old, is Dementia. Recently, epidemiological studies suggest that chronic exercise training or exercise habit decreases a risk of cerebral disease including dementia. Therefore, for many researchers it is worthy to note the relationship between cerebral disease and exercise habit. However, cerebral circulation has some complicated physiological mechanisms, thus, we do not have any physiological evidences of the effect of chronic exercise training on preventing cerebral disease. In the present research project, as a fundamental study in this research area, we demonstrated new findings about the adaptation of cerebral blood flow regulation system related to cerebral disease to chronic exercise. In addition, we found the relationship between systemic circulatory or respiratory regulation system and cerebral circulatory system in this project.
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Effect of respiratory system on circulatory regulation during exercise
Grant number：24300222 2012.4 - 2015.3
KATAYAMA KEISHO
Authorship：Principal investigator
Grant amount：\18330000 （ Direct Cost: \14100000 、 Indirect Cost：\4230000 ）
It has been thought that an increase in respiratory muscle activity affects cardiovascular regulation during exercise. We found that an enhancement of inspiratory muscle work causes an increase in sympathetic vasomotor outflow with a corresponding enhancement of arterial blood pressure during exercise. An enhancement of inspiratory muscle activity under hypoxic condition leads to large increases in sympathetic vasomotor outflow and BP. It is possible that this large vasoconstrictor activity reduces blood flow and oxygen transport to the working limb, thereby exacerbating limb fatigue and compromising exercise performance.
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呼吸系が運動時の循環調節に及ぼす影響
Grant number： 24300222 2012.4 - 2015.3
科学研究費補助金 基盤研究(B)
Authorship：Principal investigator
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Clarification of the effective way of breathing and its mechanism during aerobic exercise
Grant number：23500777 2011 - 2013
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C) Grant-in-Aid for Scientific Research (C)
ISHIDA Koji, KATAYAMA Keisho, KOIKE Teruhiko, HOTTA Norio, IWAMOTO Erika, KATAYAMA Keisho, KOIKE Teruhiko, HOTTA Norio, IWAMOTO Erika
Authorship：Coinvestigator(s)
This study revealed that (1) repeated and exaggerated ventilation during exercise produced by short term aerobic training combined with chest wall restriction or inhalation of hypoxic gas, reinforced subsequent ventilatory response to normal exercise, indicating that learning should be involved in the respiratory control during exercise, and that (2) high intensity cycle exercise often induced a locomotor-respiratory coupling and resultant easiness during exercise, while during moderate intensity cycle exercise which was often used in aerobic exercise, there was no difference in cardio-respiratory responses between coupling and non-coupling so that the locomotor-respiratory coupling should have no beneficial effect on moderate intensity exercise. These results suggest that during aerobic exercise, we should keep in mind to breathe slowly rather than to synchronize respiration to locomotion, and that appropriate breathing way during exercise could be obtained from repetitive learning.
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The interaction between respiratory and cardiovascular regulations during exercise
Grant number：22700649 2010 - 2011
KATAYAMA Keisho
Authorship：Principal investigator
Grant amount：\4160000 （ Direct Cost: \3200000 、 Indirect Cost：\960000 ）
The purpose of the present study was to elucidate 1) whether carotid chemoreceptors affects muscle sympathetic nerve activity and cardiovascular responses during exercise, and 2) the influence of inspiratory muscle fatigue on muscle sympathetic nerve activity and blood pressure.
Study 1 : Muscle sympathetic nerve activity(MSNA), cardiovascular variables, and plasma norepinephrine(NE) concentrations were measured during leg cycling at 40% and 60% of peak oxygen uptake(V. O2_<peak>) while breathing hypoxic gas mixture. MSNA during exercise in hypoxia was higher than in normoxia. These results suggest that acute hypoxia augments muscle neural activation during dynamic leg exercise, and that the MSNA response during exercise in hypoxia could be different from the change in plasma NE concentrations.
Study 2 : MSNA and cardiovascular parameters were recorded during dynamic leg cycling at 40% V. O2_<peak> with or without inspiratory resistive breathing. The time-dependent increase in MSNA appeared during exercise with inspiratory resistive breathing, accompanied by an augmentation of blood pressure(BP). These results suggest that inspiratory muscle fatigue induces increases in muscle sympathetic vasomotor ouflow and BP during dynamic exercise. -
EFFECTS OF PHYSICAL EXERCISE TRAINING ON NEURAL AND HUMORAL SYSTEMS FOR CARDIOVASCULAR REGULATION
Grant number：21300239 2009 - 2011
SAITO Mitsuru
Authorship：Coinvestigator(s)
Endurance exercise training decreases resting blood pressure and increases blood flow distribution to skeletal muscles during exercise. To reveal the mechanisms of an adaptive change in cardiovascular regulation associated exercise training, muscle sympathetic nerve activity and catecholamine as neural and humoral factors were measured during submaximal exercise in endurance trained and untrained subjects. Sympathetic neural responses were greater in the trained than in the untrained group. However, the response of the humoral factors was the same in both groups. These results indicate that an effect of the exercise training on neural and humoral responses for cardiovascular regulatory mechanisms is not identical.
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Study on the effectiveness of diet or exercise therapy for young obese males in terms of insulin resistance.
Grant number：21500682 2009 - 2011
KOIKE Teruhiko
Authorship：Coinvestigator(s)
Appropriate lifestyle choices when persons are young and healthy are critical for the maintenance of life-long health in an ageing society. In the present study, diet and exercise habits surveyed among young obese males showed various characteristics. However, each individual had different lifestyle-related problems, which would demand individualized measures. Caloric restriction with exercise for 4 weeks strongly suppressed insulin resistance and chronic inflammatory status, but the effects were weaker by caloric restriction alone, indicating importance of exercise to enhance metabolic benefits with diet therapy.
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低酸素環境における運動時の呼吸循環調節メカニズムの解明
Grant number： 20700523 2008.4 - 2010.3
科学研究費補助金 若手研究(B)
片山 敬章
Authorship：Principal investigator
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Respiratory and cardiovascular regulations during exercise in hypoxia
Grant number：20700523 2008 - 2009
KATAYAMA Keisho
Authorship：Principal investigator
Grant amount：\4420000 （ Direct Cost: \3400000 、 Indirect Cost：\1020000 ）
The purpose of the present study was to elucidate respiratory and cardiovascular responses at rest and during exercise in hypoxia. Study 1 ; the subjects breathed hypoxic gas mixture (12%O2) for 20 min. Flow-mediated vasodilation (FMD) was measured before and after hypoxic exposure. FMD was increased after acute hypoxia, suggesting that acute hypoxic exposure could improve endothelial function. Study 2 ; the subjects performed cycle exercise at 40% and 70% of maximal exercise intensity in normoxia (21%O2) and hypoxia (12.7%O2). Arterial blood pressure and muscle sympathetic nerve activity during exercise in hypoxia (hypoxic condition) differed from those in normoxia. These results suggest that arterial oxygenation could affect arterial blood pressure regulation during exercise.
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低酸素暴露に対する身体適応の反復効果
Grant number： 17700488 2005.4 - 2007.3
科学研究費補助金 若手研究(B)
片山 敬章
Authorship：Principal investigator
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The effect of training on physical capacity during unilateral limb unloading in humans
Grant number：17300207 2005 - 2008
HIROSHI Akima
Authorship：Coinvestigator(s)
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低酸素暴露に対する身体適応の反復効果
Grant number：17700488 2005 - 2006
科学研究費補助金
片山 敬章
Authorship：Principal investigator
Grant amount：\3700000 （ Direct Cost: \3700000 ）
我々のこれまでの研究結果から,1日1時間程度の間欠的な常圧低酸素環境への暴露により,高度4,300m以上,いわゆる高高所を模擬した環境においては,運動時の換気応答の増加が認められ,この増加が動脈血酸素飽和度(SaO2)の改善に貢献することが明らかにされている.これらの結果から,1日数時間程度の間欠的低酸素暴露により,高高所での高山病の軽減やパフォーマンス向上が推測される.しかしながら,この間欠的低酸素暴露がいわゆる準高所と呼ばれる高度2,500m程度における低酸素環境下での運動時の呼吸循環応答に及ぼす影響については不明である.そこで,本年度の研究では,短期間の間欠的低酸素暴露が,準高所を模擬した環境における運動時の呼吸循環応答を明らかにすることを目的とした.被験者は健康な男性21名とした(低酸素群14名,対象群7名).低酸素群をさらに酸素濃度の異なる2群に振り分けた:低酸素群1(7名),低酸素群2(7名).間欠的低酸素暴露には,低酸素テントを使用し,低酸素制御装置からの酸素濃度は低酸素群1では15.5%,低酸素群2では12.3%に設定した.1日の暴露時間は1時間,期間を7日間とした.7日間の間欠的低酸素暴露前後に15.5%の酸素ガスを吸入(高度2,500mを模擬)させ,安静時及び運動時の呼吸循環応答の測定を実施した.また,安静時において低酸素換気応答(HVR)を測定した.低酸素群2において,HVRの有意な増加が間欠的低酸素暴露後に認められたが,低酸素群1及び対照群では変化は見られなかった.高度2,500を模擬した15.5%酸素吸入による運動時の換気量及びSaO2にはすべての群において有意な変化は認められなかった.これらの結果から,短期間の間欠的低酸素暴露による低酸素換気感受性の変化は,準高所における運動時の換気応答に影響を及ぼさないことが示唆される.
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間欠的な低酸素暴露による運動効率の改善に関する研究
Grant number：15700413 2003.4 - 2005.3
科学研究費補助金 若手研究(B)
片山 敬章
Authorship：Principal investigator
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間欠的な低酸素暴露による運動効率の改善に関する研究
Grant number：15700413 2003 - 2004
科学研究費補助金
片山 敬章
Authorship：Principal investigator
Grant amount：\3500000 （ Direct Cost: \3500000 ）
間欠的低酸素暴露による最大下運動時の呼吸循環応答ならびに持久的パフォーマンスの変化を明らかにするために,以下の実験を実施した.
実験1)被験者を15名の持久的鍛練者とした(低酸素群8名,コントロール群7名).低酸素暴露:には簡易式低酸素テントを用い(酸素濃度:約12%)時間及び期間は3時間/日,2週間とした.間欠的低酸素暴露前後に最大及び最大下運動テスト,3,000mタイムトライアルを実施した.2週間の間欠的低酸素暴露後,最大運動テストにおける呼吸循環応答は両群共に変化が認められなかった.低酸素群では,最大下運動時に酸素摂取量及び心拍数の有意な低下が認められた.3000mランニングタイムは,低酸素群で向上傾向が認められたが統計的に有意な差は認められなかった.各個人の最大下運動時における酸素摂取量の変化と3000mランニングタイムの変化との関係を見るために,それぞれの変化値(Δ)を求め,単純相関にてそれぞれの関係を求めた.その結果,最大下運動時の酸素摂取量の変化と3000mランニングタイムとの間に有意な相関関係が見られた.これらの結果から,間欠的低酸素暴露による持久的パフォーマンス向上に運動時の酸素摂取量の低下が寄与することが示唆された.
実験2)被検者を13名の持久的鍛錬者とし,低酸素群6名,コントロール群7名とした.低酸素暴露の方法は実験1と同様とし,時間を3時間/日,期間を1週間とした.間欠的低酸素暴露前後に最大及び最大下運動テストを実施した.1週間の間欠的低酸素暴露後,最大及び最大下運動時における呼吸循環応答には両群共に変化が認められなかった.これらの結果から,3時間/日,1週間の間欠的低酸素暴露では運動時の呼吸循環応答に影響を及ぼさないことが明らかとなった. -
高齢者の呼気中一酸化窒素および亜酸化窒素濃度に関する研究
Grant number：13878007 2001 - 2002
科学研究費補助金 萌芽研究
宮村 実晴
Authorship：Coinvestigator(s)
平成14年度では、先の平成13年度において日常生活で規則的な身体運動(大極拳、テニス)を行っている中高齢者で得られた研究成果を踏まえ、愛知県および宮山県の高齢者を対象に、呼気中一酸化窒素および亜酸化窒素濃度と体力あるいは日常生活における身体運動能力とどのような関係を有するかを明らかにしようとした。
被験者は愛知県老人ホーム入所者および富山県庄川町に在住する65歳以上の健康な高齢者73名である。各被験者を対象に安静時の呼気ガスを採集し、呼気中一酸化窒素および亜酸化窒素濃度を測定した。アンケート調査により各被験者の日常生活における身体運動を把握する、と同時に運動能力(シャトルウオーク、筋力、柔軟性、反応時間、開眼片足立ち、閉眼片足立ち)を測定した。
その結果、握力、全身反応時間、単純反応時間、開眼片足立ちおよび閉眼片足立ちは、庄川町の高齢者の方が老人ホームの高齢者のそれよりよい成績(p<0.05)であった。また呼気中の一酸化窒素濃度も庄川町の高齢者の方が老人ホームの高齢者のそれより高かった(p<0.05)。一方、年齢と開眼片足立ち(r=-0.29)、ファンクショナルリーチ(r=-0.29)、シャトルウオーク(r=-0.31)とそれぞれ有意の相関関係が認められた。
アンケート調査による日常生活における身体活動量は、庄川町の高齢者の方が老人ホームの高齢者と比べ、できるだけ歩く、畑仕事をする、運動教室にでかける、など日常生活において自身の体を使うよう心掛けていることが明らかとなった。
以上の結果は、持久性能力(体力)あるいは運動能力は加齢と共に低下するが、体力の低下は日常生活における身体活動量に影響されることを示唆するものである。なお、庄川町の高齢者における呼気中の一酸化窒素濃度が老人ホームの高齢者のそれより何故高かったか、また呼気中の一酸化窒素濃度と体力との関係については今後の検討課題である。 -
間欠的な低酸素暴露が持久的パフォーマンスに及ぼす影響
Grant number：01J01245 2001
日本学術振興会 科学研究費助成事業 特別研究員奨励費
片山 敬章
Authorship：Coinvestigator(s)