운동경험이 없는 남성의 저항성 운동강도 차이가 근 손상 지표, 근력 및 근 비대 효과에 미치는 영향

전용균,최재일 한국체육과학회 2022 한국체육과학회지 Vol.31 No.2

This study was conducted to identify the intensity of resistance exercise that can improve muscle strength and hypertrophy while preventing muscle damage in untrained men in their 20s. Thirty men were divided into control group(n=10), low-load resistance exercise group(n=10), and high-load resistance exercise group(n=10). Resistance exercise of LLRG was performed with 40% 1RM, 3 sets, and repetitions per set until spontaneous muscle failure occurred. Resistance exercise of HLRG was performed with 80% 1RM, 3 sets, and repetitions per set until spontaneous muscle failure occurred. Resistance exercise was performed 3 times a week for a total of 12 weeks. After the end of the experiment, repeated measures ANOVA was performed to analyze the changes in the muscle damage indicator, muscle strength, and muscle hypertrophy. The results were as follows. Results of muscle damage indicator showed no significant difference in LLRG, but LDH, CK, Myoglobin, and AST significantly increased in HLRG after 12 weeks. And the result of muscle strength, both LLRG and HLRG were significantly increased, but HLRG was increased more than LLRG. In addition, the results of muscle mass were significantly increased to a similar level for both LLRG and HLRG. Summarizing the above results, it is judged that resistance exercise of 40% 1RM level of exercise intensity during the initial exercise plan for subjects without exercise experience can prevent muscle damage and increase muscle hypertrophy.

Resistance exercise: a mighty tool that adapts, destroys, rebuilds and modulates the molecular and structural environment of skeletal muscle

Käthe Bersiner,박소영,Kirill Schaaf,양우휘,Christian Theis,Daniel Jacko,Sebastian Gehlert 한국운동영양학회 2023 Physical Activity and Nutrition (Phys Act Nutr) Vol.27 No.2

[Purpose] Skeletal muscle regulates health and performance by maintaining or increasing strength and muscle mass. Although the molecular mechanisms in response to resistance exercise (RE) significantly target the activation of protein synthesis, a plethora of other mechanisms and structures must be involved in orchestrating the communication, repair, and restoration of homeostasis after RE stimulation. In practice, RE can be modulated by variations in intensity, continuity and volume, which affect molecular responses and skeletal muscle adaptation. Knowledge of these aspects is important with respect to planning of training programs and assessing the impact of RE training on skeletal muscle. [Methods] In this narrative review, we introduce general aspects of skeletal muscle substructures that adapt in response to RE. We further highlighted the molecular mechanisms that control human skeletal muscle anabolism, degradation, repair and memory in response to acute and repeated RE and linked these aspects to major training variables. [Results] Although RE is a key stimulus for the activation of skeletal muscle anabolism, it also induces myofibrillar damage. Nevertheless, to increase muscle mass accompanied by a corresponding adaptation of the essential substructures of the sarcomeric environment, RE must be continuously repeated. This requires the permanent engagement of molecular mechanisms that re-establish skeletal muscle integrity after each RE–induced muscle damage. [Conclusion] Various molecular regulators coordinately control the adaptation of skeletal muscle after acute and repeated RE and expand their actions far beyond muscle growth. Variations of key resistance training variables likely affect these mechanisms without affecting muscle growth.

14C-glucose를 이용한 시험관 실험에서 비후 골격근의 glycogen 합성능

김용운,이석강,김종연 영남대학교의과대학 1990 Yeungnam University Journal of Medicine Vol.7 No.1

Slow twitch soleus와 fast twitch plantaris근의 운동, insulin, 전기자극에 대한 반응을 시험관내에서 ??-glucose를 이용한 glycogen합성능으로 비교하고 협력근 절제 4주후에 유도한 대상성비후근의 glycogen의 합성능을 같은 방법으로 평가하여 지속적인 과부하에 따른 각 근섬유의 반응을 비교하고자 한 본 연구의 결과를 요약하면 다음과 같다. 대조군의 soleus에서는 glycogen으로 incorporation되는 glucose양으로 볼때 운동에 의한 증가는 없었으나 insulin, 전기자극등의 인자에 의해서는 증가하였으며 운동이 이들 인자들과 합쳐 졌을때는 이들의 작용을 증폭 시켰다. 그러나 plantaris에서는 운동과 전기자극을 합한 군과 모든자극을 함께 가한 군에서만 유의한 증가를 보여서 insulin이나 glucose대사의 관점에서 볼때 soleus가 훨씬 활동적임을 알수 있었다. 협력근 절제로 인한 4주간의 과부하로 인한 비후군의 glycogen합성능은 soleus에서 대조군의 그것과 양상은 비슷하였으나 그 절대량에서 크게 못미쳤으며 plantaris에서는 대조군과 매우 유사한 반응을 나타내었다. 이와같은 결과로 볼때 협력근 절제 4주후에 여러 효소의 활동도가 안정상태에 이른다는 여러 보고에 기초하면 지속적인 과부하에 대한 각 근섬유의 반응양상이 차이가 나서 fast twitch근의 근활동이 더 향상되는 것으로 사료된다. This investigation was undertaken to clarify this in vitro effect of the various stimulations, such as exercise(E), insulin(I), direct electrical stimulation(EST) and the combinations of the above, on the glucose incorporation into glycogen molecules (glycogen synthesis)of the normal slow(soleus) and fast twitch(plantaris) muscles, and the different responses of slow and fast twitch muscles to persistent overloads causing compensatory muscle hypertrophy. In resting state, slow twitch muscle has greater capacity for glycogen synthesis than fast twitch muscle, and responses of different muscle to various stimuli were differ as follows: In slow twitch muscle, the glycogen synthesis was increased by insulin, and electrical stimulation but not increased by exercise ; exercise increased insulin sensitivity and the effect of electrical stimulation. Whereas the glycogen synthesis in fast twitch muscle was increased only by the stimuli combined with E and EST, and E,I, and EST. As the result of removal of synergistic muscle, both muscles were hypertropied, and the degree of hypertrophy in response to persistent overload was higher in fast twitch muscle(182%) than slow twitch muscle(151%). In hypertrophied muscles, glycogen synthesis of soleus in any groups was lower than that of the control, but similar in plantaris. In conclusions, there were marked heterogeneity in defferent muscle fiber in the effects of exercise and insulin addition and electrical stimulation on muscle glycogen synthesis, and fast twitch muscle may be adapted more easily to that kind of persistent overload than slow twitch muscle.

Effects of different doses of leucine ingestion following eight weeks of resistance exercise on protein synthesis and hypertrophy of skeletal muscle in rats

길주현,김창근 한국운동영양학회 2015 Physical Activity and Nutrition (Phys Act Nutr) Vol.19 No.1

Ju Hyun, Gil and Chang Keun Kim. Effects of different doses of leucine ingestion following eight weeks of resistance exerciseon protein synthesis and hypertrophy of skeletal muscle in rats. JENB., Vol. 19, No. 1, pp.31-38, 2015 [Purpose]This studywas designed to determine the appropriate Leucine intake volume to obtain the effects of restoring damaged muscle through thesynthesis of muscle proteins to increase skeletal muscle and improve exercise performance, and to achieve enhanced muscle hypertrophy. [Methods] To clarify the effects of leucine on skeletal muscle hypertrophy of SD rats, following eight weeks of resistance exercise(climbing ladder), the mass of the FHL (Flexor hallucis longus) was measured after extraction, after which change in the activityof muscle signaling proteins (PKB/Akt, mTOR, p70S6K, 4EBP1) was analyzed. [Results] The expressions of PKB/Akt, mTORand p70S6K were increased in L5 (Leucine 50% administration group) compared with the control group (CON) and exercisegroup (Ex, exercise training group); EL1 (exercise + 10% leucine administration group) and EL5 (exercise + 50% Leucine administration)also exhibited increased expressions of PKB/Akt, mTOR, and p70S6K, while no difference between EL1 and EL5 were observed. No significant differences in 4EBP1 were found among any of the groups. In addition, there were no differences in FHL mass,while relative mass (FHL/body mass) was increased in the exercise group (Ex, EL1, EL5) compared with the control group. Nodifferences were observed among the exercise groups. [Conclusion] The present study demonstrated that the relative body masswas increased in the EX group compared with the CON group, while no significant differences in muscle mass could be foundamong the groups. Even though some signaling proteins were increased, or some differences existed among groups, there wereno differences in muscle mass between the leucine administration and exercise training combined with leucine administration groupsin the present study. [Key words] Leucine, dose difference, resistance exercise, mtor, muscle, protein synthesis, hypertrophy

Effects of different doses of leucine ingestion following eight weeks of resistance exercise on protein synthesis and hypertrophy of skeletal muscle in rats

( Ju Hyun Gil ),( Chang Keun Kim ) 한국운동영양학회 2015 Physical Activity and Nutrition (Phys Act Nutr) Vol.19 No.1

[Purpose] This study was designed to determine the appropriate Leucine intake volume to obtain the effects of restoring damaged muscle through the synthesis of muscle proteins to increase skeletal muscle and improve exercise performance, and to achieve enhanced muscle hypertrophy. [Methods] To clarify the effects of leucine on skeletal muscle hypertrophy of SD rats, following eight weeks of resistance exercise (climbing ladder), the mass of the FHL (Flexor hallucis longus) was measured after extraction, after which change in the activity of muscle signaling proteins (PKB/Akt, mTOR, p70S6K, 4EBP1) was analyzed. [Results] The expressions of PKB/Akt, mTOR and p70S6K were increased in L5 (Leucine 50% administration group) compared with the control group (CON) and exercise group (Ex, exercise training group); EL1 (exercise + 10% leucine administration group) and EL5 (exercise + 50% Leucine administration) also exhibited increased expressions of PKB/Akt, mTOR, and p70S6K, while no difference between EL1 and EL5 were observed. No significant differences in 4EBP1 were found among any of the groups. In addition, there were no differences in FHL mass, while relative mass (FHL/body mass) was increased in the exercise group (Ex, EL1, EL5) compared with the control group. No differences were observed among the exercise groups. [Conclusion] The present study demonstrated that the relative body mass was increased in the EX group compared with the CON group, while no significant differences in muscle mass could be found among the groups. Even though some signaling proteins were increased, or some differences existed among groups, there were no differences in muscle mass between the leucine administration and exercise training combined with leucine administration groups in the present study.

Neurogenic muscle hypertrophy: a case report

Shin, Hyun Ho,Jeon, Young Hoon,Jang, Seung Won,Kim, Sae Young The Korean Pain Society 2016 The Korean Journal of Pain Vol.29 No.4

Muscular hypertrophy is caused mainly due to myopathic disorder. But, it is also rarely produced by neurogenic disorder. A 74-year-old woman complained of right calf pain with hypertrophy for several years. Recent lumbar spine magnetic resonance imaging (MRI) showed central and lateral canal narrowing at the L4-L5 intervertebral space. Lower extremity MRI revealed fatty change of right medial head of the gastrocnemius and soleus, causing right calf hypertrophy. Electrodiagnostic examinations including electromyography and nerve conduction velocity testing demonstrated $5^{th}$ lumbar and $1^{st}$ sacral polyradiculopathy. Integrating all the results, the diagnosis was neurogenic muscle hypertrophy. Neurogenic muscle hypertrophy is very rare, but we recommend that clinicians consider this problem when a patient complains of lower limb hypertrophy and pain.

말초신경 손상 후 발생한 국소성 장딴지근육비대

오지영,정연경,박기덕,김승민,선우일남 대한근전도전기진단의학회 2009 대한근전도 전기진단의학회지 Vol.11 No.2

Muscle hypertrophy can occur unusually in various neurogenic disorders even muscle atrophy is the rule. Focal neurogenic calf muscle hypertrophy with lumbosacral radiculopathies has been frequently reported, and less often with old poliomyelitis. We report a case of neurogenic calf muscle hypertrophy after focal injury of peripheral nerve. The patient is a 10 year-old boy with progressive hypertrophy of the left calf muscle for 6 months. He had a lacerating nerve injury in the left popliteal fossa 3 years before. He underwent surgical repair, but mild weakness of the left ankle and toes was remained. Neurological examination revealed mild weakness of left ankle dorsiflexion and plantarflexion and sensory loss in the left sole and lateral aspect of the calf. Left ankle jerk was absent. Nerve conduction study and electromyography disclosed incomplete lesions of the left common peroneal and posterior tibial nerves at the popliteal fossa without compound sensory nerve action potential of the left sural nerve. Though neurogenic muscle hypertrophy is a rare clinical entity, physicians should consider this in the differential diagnosis of localized muscle hypertrophy.

Neurogenic muscle hypertrophy: a case report

신현호,전영훈,장승원,김세영 대한통증학회 2016 The Korean Journal of Pain Vol.29 No.4

Muscular hypertrophy is caused mainly due to myopathic disorder. But, it is also rarely produced by neurogenic disorder. A 74-year-old woman complained of right calf pain with hypertrophy for several years. Recent lumbar spine magnetic resonance imaging (MRI) showed central and lateral canal narrowing at the L4-L5 intervertebral space. Lower extremity MRI revealed fatty change of right medial head of the gastrocnemius and soleus, causing right calf hypertrophy. Electrodiagnostic examinations including electromyography and nerve conduction velocity testing demonstrated 5th lumbar and 1st sacral polyradiculopathy. Integrating all the results, the diagnosis was neurogenic muscle hypertrophy. Neurogenic muscle hypertrophy is very rare, but we recommend that clinicians consider this problem when a patient complains of lower limb hypertrophy and pain. (Korean J Pain 2016; 29: 270-3)

Neurogenic muscle hypertrophy: a case report

( Hyun Ho Shin ),( Young Hoon Jeon ),( Seung Won Jang ),( Sae Young Kim ) 대한통증학회 2016 The Korean Journal of Pain Vol.29 No.4

Muscular hypertrophy is caused mainly due to myopathic disorder. But, it is also rarely produced by neurogenic disorder. A 74-year-old woman complained of right calf pain with hypertrophy for several years. Recent lumbar spine magnetic resonance imaging (MRI) showed central and lateral canal narrowing at the L4-L5 intervertebral space. Lower extremity MRI revealed fatty change of right medial head of the gastrocnemius and soleus, causing right calf hypertrophy. Electrodiagnostic examinations including electromyography and nerve conduction velocity testing demonstrated 5th lumbar and 1st sacral polyradiculopathy. Integrating all the results, the diagnosis was neurogenic muscle hypertrophy. Neurogenic muscle hypertrophy is very rare, but we recommend that clinicians consider this problem when a patient complains of lower limb hypertrophy and pain. (Korean J Pain 2016; 29: 270-3)

근위축 마우스 모델에서 한국산 겨우살이 추출물에 의한 단백질 합성 신호전달 경로의 활성화

정주성 ( Juseong Jeong ),박춘호 ( Choon-ho Park ),김인보 ( Inbo Kim ),김종배 ( Jong-bae Kim ) 한국식품영양학회 2017 韓國食品營養學會誌 Vol.30 No.2

Muscle atrophy is characterized by a decrease in the mass of the muscle. With an increase in life expectancy and chronic illnesses, the incidence of muscle atrophy is increasing and the quality of life of patients is decreasing. Thus, reducing muscle atrophy is of high clinical and socio-economic importance. Mistletoe is a semi-parasitic plant that has been used as a traditional medicine in many countries to treat various human illnesses. It has been reported that Korean mistletoe extract (KME) has diverse biological functions including anti-tumor, anti-oxidant, anti-diabetic, anti-obesity properties, and extension of lifespan. Especially, we have recently reported that KME improves exercise endurance in mice, indicating its beneficial roles in enhancing the capacity of skeletal muscle. In this study, we investigated whether KME could activate the signaling pathway related to protein synthesis in a mouse model of muscle atrophy. Interestingly, KME efficiently activated the Akt/mTOR pathway, and Akt and mTOR are important signaling hub molecules for the acceleration of protein synthesis in muscle cells. In addition, KME also increased the activity of S6 kinase which is involved in the regulation of muscle cell size. Moreover, the ERK activity, required for transcription of ribosomal RNA for protein synthesis, was also enhanced in KME-treated mouse muscle. These data support the idea that KME increases muscle mass via increased protein synthesis. Our findings also suggest that Korean mistletoe might be a promising candidate for the development of functional foods that are beneficial for preventing muscle atrophy.