著者

千村 晃

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.63, no.1, pp.128, 2014 (Released:2014-01-24)

参考文献数

2

著者

苅山 靖 林 陵平 吉田 拓矢 図子 あまね 図子 浩太佑 図子 浩二

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.2, pp.187-197, 2018-04-01 (Released:2018-03-16)

参考文献数

44

被引用文献数

1

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Movement control and muscle function for pelvic movement in the frontal plane (pelvic elevation) are important for various single-leg sports activities. We aimed to clarify mechanical characteristics of pelvic squat (P-Sq: single-leg squat exercise with emphasis on pelvic elevation, developed by our research group) compared with the double-leg squat (D-Sq) and single-leg squat (S-Sq). Twelve male track and field athletes performed D-Sq, S-Sq, and P-Sq exercises at various loads (90%, 75%, and 60% of 1-repetition maximum [1RM]), using maximum effort. Kinematic and kinetic data were calculated using data recorded with a motion capture system and force platforms. We observed the highest values with P-Sq, followed by S-Sq and D-Sq under all load conditions as follows: peak vertical ground reaction force and rate of force development (RFD), range of pelvic elevation, peak pelvic elevation velocity, peak powers associated with hip abduction torque and trunk lateral flexion torque. In P-Sq, RFD at 90% 1RM was smaller than under the other load conditions, whereas peak vertical ground reaction force at 90% 1RM was larger than under the other load conditions. There were no differences among load conditions with regard to hip abduction and trunk lateral flexion torques and powers. Therefore, characteristics of P-Sq compared to those of D-Sq and S-Sq are 1) larger and faster pelvic elevation, using related muscles (hip abductors and trunk lateral flexors) under all load conditions, 2) larger peak ground reaction force with pelvic elevation under large load conditions, and larger RFD in pelvic elevation under low load conditions.

著者

半田 徹 加藤 浩人 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.54, no.2, pp.159-168, 2005 (Released:2006-12-01)

参考文献数

22

被引用文献数

3 7

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To compare the effectiveness of five different muscle training movements on the biceps brachii, latissimus dorsi and trapezius muscles, eight weight-trained men (age, 20.4±0.5 years) were asked to perform three repetitions, at 70% one repetition maximum, of upright rowing (UR) and bent-over rowing (BR) exercises using a barbell ; and seated rowing (SR), front lat pull-down (LPf) and back lat pull-down (LPb) exercises using a Universal Machine. The activities of the biceps brachii, latissimus dorsi, and trapezius during the elbow flexsion and elbow extension phases of each exercise were analyzed using integrated electromyography (EMG) and normalized I-EMG. The results were as follows :1. The mean nrmsEMG values for the biceps brachii were larger during UR and LPf exercises than during BR, SR, and LPb exercises, suggesting that UR and LPf are more effective than the other movements for training the biceps brachii. The mean nrmsEMG values for the latissimus dorsi were larger during SR, LPf, and LPb exercises, followed by BR and UR exercises (in descending order), suggesting that SR, LPf, and LPb exercises are more effective than the other movements for training the latissimus dorsi.2. The mean nrmsEMG values for the upper trapezius were larger during UR and BR exercises than during SR, LPf, and LPb exercises, suggesting that UR and BR exercises are more effective than the other movements for training the upper trapezius. The mean nrmsEMG values for the middle trapezius were larger during BR and SR exercises than during UR, LPf, and LPb exercises, suggesting that BR and SR exercises are more effective than the other movements for training the middle trapezius. The mean nrmsEMG values for the lower trapezius were larger during BR exercise than during other movements, suggesting that BR exercise is more effective than the other movements for training the lower trapezius.3. In all the exercises, each muscle showed a higher nrmsEMG value during the elbow flexsion phase than during the elbow extension phase. This observation suggests that the training method examined in this study should emphasize the elbow flexsion movement.The present results suggest that UR exercise is the most effective movement for training the biceps brachii and upper trapezius, BR is most effective for training the upper trapezius, middle trapezius and lower trapezius, SR is most effective for training the latissimus dorsi and middle trapezius, LPf is most effective for training the biceps brachii and latissimus dorsi, and LPb is most effective for training the latissimus dorsi.

著者

福 典之

出版者

一般社団法人日本体力医学会

雑誌

体力科学 (ISSN:18814751)

巻号頁・発行日

vol.61, no.1, pp.28-28, 2012 (Released:2012-03-14)

著者

相澤 勝治

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.5, pp.455-462, 2016-10-01 (Released:2016-10-03)

参考文献数

47

被引用文献数

2

---

The plasticity of skeletal muscle facilitates adaptation to various stimuli. Sex steroid hormones (androgens and estrogens) are involved in a variety of physiological and pathological processes. In skeletal muscle, sex steroid hormones affect growth, strength, metabolism, and antioxidant levels and are associated with exercise-induced skeletal muscular adaptation. Sex steroid hormone levels also decrease with aging and are thought to be a factor in muscle atrophy. Though sex steroid hormones play an important role in skeletal muscular homeostasis, the role of the endocrine system in muscle plasticity is unknown. Sex steroid hormones are synthesized from cholesterol by steroidogenic enzymes, such as 3β-hydroxysteroid dehydrogenase (HSD), and 17β-HSD, with testosterone being irreversibly converted to estrogen by aromatase cytochrome P450 (P450arom). Testosterone is also converted into its bioactive metabolite dihydrotestosterone (DHT) by 5α-reductase. Sex steroid hormones are produced by various peripheral target tissues including the kidney, liver, and brain in addition to endocrine organs such as the testis or ovary in the recent research. For instance, steroidogenic enzymes expressed in skeletal muscle have been reported to locally synthesize sex steroid hormones from circulating dehydroepiandrosterone (DHEA) or testosterone in response to exercise. Thus, local steroidogenesis in skeletal muscle provides further evidence for the presence of an autocrine/paracrine system for sex steroid hormones and their roles in skeletal muscle function and adaptation. This review focuses on the steroidogenesis of skeletal muscle and discusses the physiological significance of the sex steroid hormones network of circulation and skeletal muscle.

著者

Koichiro Azuma Yusuke Osawa Shogo Tabata Fuminori Katsukawa Hiroyuki Ishida Yuko Oguma Toshihide Kawai Hiroshi Itoh Shigeo Okuda Shuji Oguchi Atsumi Ohta Haruhito Kikuchi Mitsuru Murata Hideo Matsumoto

出版者

一般社団法人日本体力医学会

雑誌

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

巻号頁・発行日

vol.6, no.2, pp.103-110, 2017-03-25 (Released:2017-03-19)

参考文献数

27

被引用文献数

3

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High-intensity interval training (HIIT) has recently received much attention as a new option for aerobic training. Despite its smaller time requirement, HIIT has been reported to have a greater effect than continuous moderate-intensity training on fat loss, especially a decrease in truncal adiposity. We therefore examined whether long-term HIIT preferentially modulates truncal adiposity rather than peripheral adiposity, especially thigh adiposity, where local muscle energy consumption increased profoundly during HIIT. We also examined the association between changes in adipose tissue distribution and serum adiponectin level. Twelve healthy male participants (28-48 years old) were assigned to a group that performed HIIT using only a leg ergometer (L-HIIT, n = 7) or to a group that performed HIIT using both leg and arm ergometers (LA-HIIT, n = 5) twice weekly for 16 weeks. The training programs consisted of 8 to 12 sets of >90% VO2 peak for 1 min, with 1 min of very light active recovery. Body composition analyses as well as aerobic fitness and measurements of serum adiponectin were performed at baseline and after intervention. A linear improvement in aerobic fitness was observed along with a decrease in leg fat (5.4 ± 1.7 vs. 5.1 ± 1.7 kg, p < 0.05) near the main working muscles during HIIT in the combined (L+LA-HIIT) group. Moreover, there was an association of decrease in leg fat or thigh adiposity with improvement in aerobic fitness in the combined group (ρ = -0.59, p < 0.05; and ρ = -0.71, p < 0.05, respectively). Visceral adiposity was decreased in L-HIIT (115 ± 45 vs. 100 ± 47 cm2, p < 0.05), however no decrease was observed in total fat or truncal fat in either group. No change was observed in serum adiponectin concentration in either group. Changes in serum adiponectin were associated with changes in visceral adiposity in the combined group (ρ = -0.72, p < 0.01). Regional rather than whole-body fat loss was observed after a 16-week HIIT program.

著者

TAKASHI ABE YOSHIMI TAKIGUCHI MASAHIRO TAMURA JUNKO SHIMURA KEN-ICHI YAMAZAKI

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.44, no.2, pp.225-237, 1995-04-01 (Released:2010-09-30)

参考文献数

20

被引用文献数

13 19

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For endurance exercise in swimming mice, 1.8% VAAM (Vespaamino acid mixtiure) which has the same amino acid components as hornet (Vespamandarinia) larval saliva, 1.8% casein amino acid mixture (CAAM), 10% glucose, or amino acid mixtures in which the amino acids were varied while maintaining the same molar ratio as VAAM were administered orally to mice. Mice recieving 1.8% VAAM showed significantly longer maximum swimming times than mice receiving other nutrients. Among these nutrients, mixtures of proline, glycine, and essential amino acid mixture (EAAM) from the VAAM component, showed maximum times near those with VAAM. In swimming exercise in mice earring of 0.3g tail weight, mice administered 1.8% VAAM showed lower blood lactate concentrations and higher blood glucose concentrations than mice recieving other nutrients. Mice recieving 1.8% VAAM also had lower lactate concentrations in muscle as well as blood. This suggests that VAAM suppresses lactate production and glucose catabolism during exercise. The effects of hornet larval saliva were stronger than those of VAAM. VAAM therefore showed the major effect of the saliva. The results suggest that VAAM improves physiological condition during endurance exercise. A positive correlation was observed between the blood concentrations of lactate and glucose in exercising mice administered various nutrients (r=0.779) . This suggests metabolic equilibration between glucose and lactate during exercise. A positive correlation (r=0.507) was also found between the maximum swimming time and blood glucose concentration. Maximum swimming times were highest at low (Ca. 2.5 mMol) and high (Ca. 4.0 mMol) blood lactate concentrations in high blood glucose concentrations. These facts support that glucose homeostasis is important in prolonged exercise.

著者

Yasuko Manabe Nobuharu L. Fujii

出版者

一般社団法人日本体力医学会

雑誌

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

巻号頁・発行日

vol.5, no.5, pp.373-377, 2016-11-25 (Released:2016-11-10)

参考文献数

26

被引用文献数

3

---

Skeletal muscle has an important role besides its obvious function in physical movement and locomotion; namely, it maintains whole-body metabolism. Maintaining muscle mass and quality with regular exercise is closely related to quality of life and a healthy life expectancy. However, the ways that exercise, and muscle contraction, in particular, contribute to our health has not been analyzed in detail. Progressive elucidation of the intracellular mechanisms underlying the metabolic changes induced by exercise/contraction and the hormones secreted from skeletal muscle (called myokines) is providing new insights into how exercise affects our health. To research these mechanisms in muscle contraction, various in vivo and in vitro experimental models have been developed. This review article outlines the existing skeletal muscle contraction models in rodents. Each model has its advantages and disadvantages. It is important to keep such features in mind when selecting an appropriate contraction model for the particular experimental purpose.

著者

Masaki Mizuno Jere H. Mitchell Scott A. Smith

出版者

一般社団法人日本体力医学会

雑誌

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

巻号頁・発行日

vol.5, no.5, pp.339-347, 2016-11-25 (Released:2016-11-10)

参考文献数

120

被引用文献数

4

---

The cardiovascular response to physical exercise is abnormally exaggerated in hypertension. Since such responses potentially increase the risk for adverse cardiovascular events, it is clinically important to elucidate the cause of this cardiovascular hyper-excitability in this disease. Even if blood pressure is normal at rest, individuals displaying a heightened blood pressure response to exercise are more likely to develop future hypertension. Therefore, early detection of this abnormal circulatory response to physical activity could lead to the early treatment as well as prevention of hypertension. Much evidence suggests that the abnormal exercise pressor reflex (EPR; a reflex originating in exercising skeletal muscle) significantly contributes to the generation of the enhanced circulatory responses in this disease. In addition, it has been demonstrated that the EPR dysfunction is mediated by both mechanically-sensitive fibers associated with the muscle mechanoreflex and chemically-sensitive fibers associated with the muscle metaboreflex. This review focuses on the underlying mechanisms for this overactive EPR function in hypertension. Specifically, updates on our current understanding of the EPR in this disease as well as experimental models used to examine this reflex are presented.

著者

Jun Tanihata Shin’ichi Takeda

出版者

一般社団法人日本体力医学会

雑誌

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

巻号頁・発行日

vol.5, no.4, pp.309-312, 2016-09-25 (Released:2016-10-03)

参考文献数

38

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Duchenne muscular dystrophy (DMD) is a life-limiting X-linked genetic disorder caused by a lack of the membrane-associated protein dystrophin. The absence of dystrophin increases the susceptibility of muscle fibers to damage. Repeated damage results in ineffective muscle repair and the development of pseudo-hypertrophied muscles; these bulky muscles are weak despite their size. The mechanisms underlying the functional impairments in dystrophic muscle have not yet been fully determined. However, several recent studies indicate that elevated intracellular Ca2+ homeostasis is a cause or facilitator of the development of muscle weakness in DMD. This review focuses on abnormalities of Ca2+ homeostasis and the possibilities for treatment by counteracting the Ca2+ dysregulation.

著者

Takayuki Inami Yasuo Kawakami

出版者

一般社団法人日本体力医学会

雑誌

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

巻号頁・発行日

vol.5, no.4, pp.313-317, 2016-09-25 (Released:2016-10-03)

参考文献数

46

被引用文献数

23

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Assessing muscle mechanical properties such as hardness and stiffness has important clinical implications. The use of ultrasound elastography to assess individual muscle hardness or stiffness has been increasing in recent years. Several different ultrasound elastography methods are currently in use, including strain elastography and shear wave elastography, which are capable of capturing the distribution of hardness and stiffness within individual muscles. In the present review, we outline some of the current basic and clinical applications of strain elastography and shear wave elastography, and illustrate how such ultrasound elastography technologies may further advance understanding of individual muscle mechanical properties as well as muscle functions.

著者

小野 悠介 永富 良一 Peter S. Zammit

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.59, no.1, pp.25-25, 2010 (Released:2010-04-16)

被引用文献数

3

著者

三井 利仁

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.65, no.1, pp.60-60, 2016

著者

大平 充宣 石原 昭彦

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.51, no.1, pp.165-171, 2002-02-01 (Released:2010-09-30)

参考文献数

28

著者

齊藤 美奈子 加賀谷 〓彦 森井 秀樹 中川 喜直 木村 直人 吉田 博幸 広田 公一

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.40, no.1, pp.31-40, 1991

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大学の男子競歩選手5名 (選手群) と体育専攻男子大学生5名 (対照群) を被検者とし, 競歩と普通歩行におけるスピードと酸素需要量・歩長, 歩数の関係から, 競歩の特性, 競歩の健康の維持・増進のための運動としての有用性について検討を行ったが, その結果, 次のように要約された.<BR>1.本研究における競歩の限界スピードは, 選手群が200~220m/min, 対照群が160m/minであった.普通歩行の限界スピードは両群とも140m/minであった.<BR>2.競歩と普通歩行の境界スピードは, 両群とも約130m/minにみることができ, 普通歩行はその直後に限界に達しているが, 約130m/minより低スピードにおいて, 競歩は普通歩行より効率が悪いが, それ以上のスピードでは効率が良いということがわかった.<BR>3.選手群の普通歩行, 対照群の両歩行のoptimal speedは60m/minであった.これに対し, 選手群の競歩におけるoptimal speedは60~80m/minであり, やや高いスピードまでみることができた.<BR>4.選手群は, 両歩行とも対照群のそれより同一スピードにおいて小さい酸素需要量を示しており効率よく歩くことができた.<BR>5.選手群は, 競歩において歩行の限界まで歩長, 歩数とも増加を示したが, 選手群の普通歩行と対照群の両歩行は, 歩幅が80cm付近で, 歩長が限界に達し, その後のスピードの増加は, 歩数の増加によって得ているが, やがて歩数の増加も限界に達し, 歩行困難になるということがわかった.<BR>6.競歩における選手群と対照群の歩長と歩数の差を比較すると, 歩数より歩長に大きな違いをみることができ, 速いスピードまで歩くには, 歩長を大きくできることが条件になると考えられる.<BR>7.対照群に競歩を行わせた場合, 選手群ほど歩長を伸ばすことはできず, 歩行スピードを高めることはできないが, 普通歩行よりは速いスピードの160m/minまで歩行を可能とし, この時, 77.5%Vo<SUB>2</SUB>maxの強度に相当する運動を行うことができた.これにより, 競歩は呼吸循環器系の改善に十分効果的な強度の運動法であることが示唆された.

著者

Akihiro Sakamoto Peter James Sinclair Hisashi Naito

出版者

一般社団法人日本体力医学会

雑誌

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

巻号頁・発行日

vol.5, no.2, pp.153-166, 2016-05-25 (Released:2016-05-14)

参考文献数

73

被引用文献数

8

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Isoinertial resistance is imposed during natural human dynamics, where muscles contract at varying velocities and joint angles. In many sports, the ability to produce greater force at faster speed is essential for successful outcomes. Hence, power training under isoinertial resistance (e.g., body mass, weights or flywheel, etc.) provides event-specific adaptive stimuli. Conventional power training consists of a combination of strength-oriented (> 70% 1RM) and speed-oriented (< 30% 1RM, e.g., plyometrics) methods, with the aim of being able to overcome variable external loadings across a range of velocities. An alternative maximum power output training (Pmax training, 30-70% 1RM) has been found to elicit equivalent or greater effectiveness compared to the conventional methods. It is, however, difficult to precisely reproduce the prescribed intensities, given several concerns associated with 1RM testing and the variable accuracies of the repetition-intensity or velocity-intensity relationship. No matter what level of resistance is assigned to an exercise, it is far more important to exert as much effort (or fastest concentric speed) as possible per repetition, otherwise, the training effects are reduced. At light intensities, however, a large portion of the concentric phase is spent in deceleration for the subsequent phase transition, which may limit effort. Making projectile motions, therefore, are necessary. The utilization of stretch-shortening cycle effects, with increased power ability, may give a further training edge. Coaches and trainees should be aware that successful movements in power training are defined as greater acceleration, speed and displacement for every repetition, rather than simply neat form or smooth repetitiveness.

著者

熊谷 秋三 右田 孝志 花村 茂美 日高 己喜 森山 善彦 佐々木 悠

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.46, no.4, pp.415-421, 1997-08-01 (Released:2010-09-30)

参考文献数

34

被引用文献数

1 2

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本研究は, 男子大学生の陸上長距離選手 (n=12) のHDL-cと性ホルモン, SHBG及びOBLA-SPで測定された体力との関連性を横断的に検討ことが目的である.陸上長距離選手のHDL-c水準は高水準 (平均67.8mg/dl) にあったが, 大きな個体差 (44~93mg/d1) が認められた.血中エストラディオール (E2) は, Apo AIとの間に有意な正相関を認めた.遊離テストステロンは, HDL3-c及びApo AIIとの間に有意な正相関を認めた.また, SHBGはHDL-c及びHDL2-cとの間に有意な正の相関を認めた.年令, 体脂肪率, 体脂肪分布尺度および体力と脂質代謝指標との間には, 有意な相関は認めなかった.これらの成績より, トレーニングされた陸上長距離選手においても, 男性ホルモンおよびSHBGのみでなく女性ホルモンもHDL-c代謝に深く関与しており, 有酸素トレーニング状態におけるHDL-c水準の個体間変動に性ホルモンの関与が示唆された.

著者

小倉 裕司 内藤 久士

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.48-48, 2008-02-01 (Released:2008-08-06)

著者

江崎 和希 宮上 寛之 圓 吉夫

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.45, no.4, pp.429-439, 1996-08-01 (Released:2010-09-30)

参考文献数

26

被引用文献数

1

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本研究は, 初心者や一般愛好家の参加が認められているトライアスロン競技のなかの一つであるミドルディスタンスタイプを取り上げ, 被検者8名を対象とし, それが生体にどのような影響を及ぼすかということについてロングディスタンスタイプのトライアスロン競技の値との差を比較検討することを目的とした.採血は, 競技前日, 競技終了直後, 競技翌日に行った.1) RBC, Hb, 血糖値は, 競技前日, 競技終了直後, 競技翌日において有意な変動はみられなかった.2) WBCは, 競技終了直後, 有意な上昇を示し, 競技翌日には, 競技前日の値に回復した.3) 血清CPK, LDH, GOT活性値は, 競技直後, 有意な上昇を示した.さらに血清CPK活性値は, 競技翌日, 競技前日の値に比べ著しい上昇を示した.4) 腎機能を反映する血清クレアチニン値は, 競技終了直後, 有意な上昇を示したが, 翌日には競技前日の値へ回復した.また, 血清尿酸, 血清BUNは, 競技終了直後, 有意な上昇を示し翌日も同様な値を維持していた.これらの結果とロングディスタンスタイプのトライアスロン競技の先行研究の値と比較検討した結果, ミドルディスタンスタイプのトライアスロン競技は, 血清CPK活性値の上昇率が6分の1ほどであり, 血清GOT活性値や血清GPT活性値の上昇率も比較的少なかった.このことからミドルディスタンスタイプのトライアスロン競技は, 骨格筋や肝臓への影響が比較的少ないことが示唆された.しかし, すべての酵素活性とも安静時あたりより明らかに上昇しており, 生体への影響は無視できないと考えられる.また, 初心者や一般愛好家がトライアスロン競技に参加するうえで, 自分の体力レベルを十分に把握し, レベルに合わせたレースを楽しむならば, ミドルディスタンスタイプのトライアスロン競技は, ロングディスタンスタイプのトライアスロン競技に比べ生体への負担が少ないと考えられた.

著者

Daisuke Hoshino Yu Kitaoka Hideo Hatta

出版者

一般社団法人日本体力医学会

雑誌

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

巻号頁・発行日

vol.5, no.1, pp.13-23, 2016-03-25 (Released:2016-03-18)

参考文献数

87

被引用文献数

1 13

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High-intensity interval training (HIIT) consists of repeated short bursts of high-intensity exercise and rest. Here we review recent work focusing on the metabolic adaptations to HIIT, especially in oxidative capacity and substrate availability in skeletal muscle. In this review, HIIT is defined as chronic training, for at least 2 weeks, involving repeated short-duration high-intensity exercise at >85% VO2 max, followed by complete rest or active rest, for any given duration of exercise and rest. First, we describe the effects of HIIT on muscle substrate oxidative metabolism, specifically in terms of mitochondria and substrate transporters. HIIT changes muscle mitochondrial content, function and dynamics. HIIT increases the protein content of transporters of glucose, lactate and fatty acids in skeletal muscle. These adaptations of mitochondria and transporter proteins improve oxidative capacity and substrate availability in skeletal muscle. Second, we introduce a potential mechanism of HIIT-induced adaptations in skeletal muscle, focusing on mitochondrial biogenesis. It is well known that a mechanism of mitochondrial biogenesis involves PGC-1alpha protein and its upstream signaling pathways including Ca2+/calmodulin-dependent protein kinase, AMP-activated protein kinase and mitogen-activated protein kinase p38. Given that mitochondrial biogenesis occurs in an exercise-intensity-dependent manner, mobilization of fast-twitch fibers and lactate accumulation are important. Finally, we discuss the future direction of HIIT research, involving systems biology approaches such as omics technologies and mathematical modeling, which may overcome current limitations and accelerate our understanding of mechanisms of HIIT-induced adaptations.