Menopause Induces Physical Inactivity through Brain Estrogen Receptor and Dopamine Signaling

강년주,김동일,박영민 한국운동생리학회 2023 운동과학 Vol.32 No.1

PURPOSE: Genes had selectively evolved to enhance the motivation for physical movement in human during the Paleolithic era. To prepare for a potential forthcoming food deficiency, high physical activity was essential for survival in the environment where hunting wild animals and gathering plants. In modern society, however, developing technology and engineering has made human life easier to accomplish tasks with not much movement and effort, resulting in a profound deficiency in physical activity (i.e., physical inactivity). METHODS: In this review, the authors summarized previous studies searched by the PubMed, Google Scholar, and Science Direct databases. RESULTS: Reduced physical activity is significantly associated with the high prevalence of various diseases including metabolic syndrome, obesity, sarcopenia, and cancer. Unfortunately, in women, menopause negatively impacts their body and physiology mainly due to the loss of estrogens, which also contributes to behavioral changes such as a significant reduction of physical activity levels during menopausal transition. In this review, the author focused to describe the underlying brain mechanism by which menopause results in reduced levels of physical activity through estrogens, estrogen receptors, and dopamine signaling in the nucleus accumbens, the main controller for exercise motivation. CONCLUSIONS: Estrogen receptor, specifically ERα, and dopamine receptors are the main controllers for voluntary physical activity. Furthermore, high running motivation is associated with enhanced dopamine activity. More studies are needed to verify whether enhanced dopamine activity can protect against menopause-associated reduction in physical activity.

뇌자극(Brain Stimulation)은 우리의 움직임을 변화시킬 수 있을까?

강년주 한국스포츠정책과학원 2022 스포츠과학 Vol.159 No.-

드롭 착지 시 스포츠 테이핑이 하지의 충격력과 근육 조율에 미치는 영향

강년주 ( Nyeon Ju Kang ),채원식 ( Woen Sik Chae ) 한국운동역학회 2010 한국운동역학회지 Vol.20 No.2

The purpose of this study was to evaluate the biomechanical effect of sports taping on the lower limb during drop landing. Twelve male university students who have no musculoskeletal disorder were recruited as the subjects. Principal strain, median frequency, vertical GRF, loading rate, angular velocity and resultant joint moment were determined for each trial. For each dependent variable, paired t-test was performed to test if significant difference existed between taped and untaped conditions(p<.05). The results showed that principal strain of the thigh and the shank in taping group were significantly less than those found in control group. These indicated that sports taping may prevent excessive mechanical strain caused by impact force during the deceleration phase. Flexion(-)-extension(+) and varus(-)-valgus(+) resultant joint moment of the knee joint in taping group were greater than corresponding value for control group. It seems that extensor muscle of the knee joint were not only supported by sports taping during knee flexion but also sports taping is effective for minimizing the possibility of injury.

발달장애 아동의 운동중재 참여를 통한 체력 및 문제행동에 대한 효과검증: 근거기반 운동프로그램 개발을 중심으로

박영민,강년주,김윤성,김동일 한국운동생리학회 2024 운동과학 Vol.33 No.2

PURPOSE: Developmental disabilities often result in decreased physical fitness and problematic behaviors. Participating in regular physical activity and exercise is one of the main ways to improve problems associated with developmental disabilities. In this study, we aimed to develop an evidence-based exercise program tailored to the characteristics, disability level, and functional level of children with developmental disabilities. METHODS: The development process is composed of the following nine steps: preliminary literature review, survey of physical activity participation, first expert group discussion, development of the first exercise program, feasibility study, focus group interview, second expert group discussion, development of the evidence-based exercise program, the validation of the developed exercise program. RESULTS: Participating in the evidence-based exercise program developed in this study was found to significantly improve cardiovascular fitness (6-minute walk), agility (standing long jump), and muscular function (sit-ups), but did not yield significant results in terms of flexibility (sit-and-reach). Additionally, the exercise program showed significant results in terms of reducing problem behaviors. The parents of children with developmental disabilities were all satisfied with the exercise program and its outcomes. CONCLUSIONS: The evidence-based exercise program developed in this study had positive effects on the physical fitness and behavior of children with developmental disabilities. This study provides a basis for the development of exercise programs through a safe and effective means for children with developmental disabilities.

Effects of Resistance Exercise Training on Aged Skeletal Muscle: Potential Role of Muscle Stem Cells

김동일,강년주,박영민 한국운동생리학회 2023 운동과학 Vol.32 No.2

PURPOSE: The prevalence of sarcopenia, which can lead to disability, hospitalization, and death, is increasing among older populations. Resistance exercise training (RT) is currently the most effective strategy for combating sarcopenia by stimulating hypertrophy and increasing strength. This review describes the underlying mechanisms of aging skeletal muscle and whether RT attenuates aging-related loss of muscle function and mass. METHODS: We reviewed and summarized previous research using PubMed, Science Direct, and Google Scholar databases. RESULTS: Load-induced muscle growth is a complex phenomenon that depends on various physiological systems and signaling pathways. Muscle growth occurs through signaling events arising from mechanical stress and consequent muscle protein turnover controlled by the balance between protein synthesis and degradation, which is negatively affected by aging. The authors used the myonuclear domains mediated by muscle satellite cells to explain the molecular machinery of exercise-induced muscle growth and recovery in aging muscles. CONCLUSIONS: Despite a blunted molecular response to an exercise bout, aging muscle cells demonstrated remarkable plasticity, with substantial improvements in myofibril size and strength during RT. More studies are necessary to elucidate the specific mechanisms by which RT activates muscle satellite cells and mitogenic and myogenic signaling in aged muscles.

호르몬 대체 요법 제공이 폐경기 이후 여성들의 운동기능에 미치는 영향: 체계적 문헌고찰 및 메타분석 연구

이한얼,박영민,강년주 한국운동역학회 2022 한국운동역학회지 Vol.32 No.2

Objective: The purpose of this systematic review and meta-analysis was to investigate potential effects of HRT (hormone replacement therapy) on motor functions in postmenopausal women. Method: In this meta-analysis, 19 studies that examined changes in motor functions between postmenopausal women with and without HRT intervention were qualified. We additionally conducted moderator variable analyses including: (1) motor function type, (2) hormone type, and (3) duration of HRT intervention. Results: The random effects model showed no significant overall effects (SMD = 0.199; SE = 0.115; 95% CI = -0.026~0.425; Z = 1.730; p = 0.084; I2 = 93.258%). Additional three moderator variable analyses revealed no significant effect sizes indicating that specific HRT protocols did not improve different motor functions in postmenopausal women. Conclusion: These meta-analytic findings suggest that HRT had no positive effects on motor functions in postmenopausal women.

실시간 비침습적 뇌전기 자극이 양손 힘 조절능력에 미치는 영향

이태리,이준호,강년주 한국운동역학회 2022 한국운동역학회지 Vol.32 No.4

Objective: The purpose of this study was to investigate potential effects of transcranial direct current stimulation (tDCS) on bimanual force control capabilities in healthy young adults. Method: Eighteen right-handed healthy young adults (10 females and 8 males; age: 23.55 ± 3.56 yrs) participated in this crossover design study. All participants were randomly allocated to both active-tDCS and shamtDCS conditions, respectively. While receiving 20 min of active- or sham-tDCS interventions, all participants performed bimanual isometric force control tasks at four submaximal targeted force levels (i.e., 5%, 10%, 15, and 20% of maximal voluntary contraction: MVC). To compare bimanual force control capabilities including force accuracy, variability, and regularity between active-tDCS and sham-tDCS conditions, we conducted two-way repeated measures ANOVAs (2 × 4; tDCS condition × Force levels). Results: We found no significant difference in baseline MVC between active-tDCS and sham-tDCS conditions. Moreover, our findings revealed that providing bilateral tDCS including anodal tDCS on left primary motor cortex (M1) and cathodal on right M1 while conducting bimanual force control trials significantly decreased force variability and regularity at 5%MVC. Conclusion: These findings suggest that providing bilateral tDCS on M1 areas may improve bimanual force control capabilities at a relatively low targeted force level.

골프 드라이브 스윙 시 압축 밴드를 적용한 기능성 의류가 신체의 운동역학적 변인에 미치는 영향

채원식 ( Woen Sik Chae ),강년주 ( Nyeon Ju Kang ) 한국운동역학회 2011 한국운동역학회지 Vol.21 No.3

The purpose of this study was to determine how spandex wear with compressive band affects biomechanical parameters during a golf swing. Nine male golf players, each with at least 6 years golf experienc(handy 4.5±5.4), were recruited as the participants. Eight pairs of surface electrodes were attached to the left and right side of the body to monitor the pectoralis major(PM), external abdominal oblique(AO), erector spinae(ES), and vastus lateralis(VL). This study showed that the angular velocity of the club in EG were increased during the down swing phase but X-Factor and X-factor Stretch were reduced. Average and maximum nEMG (normalized EMG) values of the left AO(external abdominal oblique) were less in EG(experimental group) compared with CG(control group) during the back swing, whereas those of left PM(pectoralis major) in EG were greater than CG. It is more likely that EG performed effectively golf swing without excess muscle activity. Thus, the spandex wear with compressive band played an important role in improving swing performance with injury prevention. This has led to suggestions of the need for further kinetic and kinematic analyses to evaluate its function.

축구 인스텝 킥 시 상지의 이용 유무가 하지의 운동학적 변인에 미치는 영향

채원식 ( Woen Sik Chae ),강년주 ( Nyeon Ju Kang ),김종우 ( Jong Woo Kim ),윤창진 ( Chang Jin Yun ),채수덕 ( Su Duk Chae ),석창혁 ( Chang Huk Seok ),박기용 ( Gi Yong Park ),임영태 ( Young Tae Lim ) 한국운동역학회 2010 한국운동역학회지 Vol.20 No.1

The purpose of this study was to evaluate the kinematic effect of upper extremity usage for the scoccer instep kick motion. Ten male university students were recruited as the subjects. Temporal parameters, ball velocity, velocity of CG, angle of segment, angular velocity, and trunk orientation angle were determined for each trial. The results showed that temporal parameters in WU and WORU were significantly less than those found in WOU during pre impact phase. These indicated that no usage of upper extremity may increase excessive setup time in order to improve the accuracy of instep kick. Angle of right knee in WOU at LC was significantly greater than corresponding value for WU since angular momentum contributions of the lower limb were not effectively balanced by contributions of the upper limb. We found that the lower extremity movement was controlled by lateral movement in the trunk as a result of no usage of the upper extremity, resulting in the relatively greater trunk rotation in WOU.

드롭 착지 동작 시 탄성 섬유 바지 착용이 충격력과 근육 활동에 미치는 영향

채원식 ( Woen Sik Chae ),강년주 ( Nyeon Ju Kang ) 한국운동역학회 2009 한국운동역학회지 Vol.19 No.3