중년 남성에 있어서 QTc interval과국소 지방량 및 최대산소 섭취량과의 관련성

김맹규 ( Maeng Kyu Kim ) 한국스포츠정책과학원(구 한국스포츠개발원) 2014 체육과학연구 Vol.25 No.2

이 연구의 목적은 중년 비만남성을 대상으로 QTc interval에 따른 신체조성, 혈액성분, 최대산소 섭취량(maximal oxygen consumption, VO2max)및 국소 지방량을 비교분석하여 관련성을 조사하는 것이다. 이 연구는 심장돌연사의 위험성과 관련한 비정상 QTc interval(≥440ms) 집단과 연령 및 체질량지수(body mass index, BMI)가 유사한 정상 QTc interval(≤430ms) 집단으로 배정하였다. 신체조성, 혈액성분, VO2max 및 컴퓨터 단층촬영(computerized tomography, 이하 CT)와 이중에너지 방사선 흡수 계측법(dual-energy x-ray absorptiometry, 이하 DEXA)에 의한 국소 지방량의 차이를 분석하였고, 전체 집단에서 QTc interval과 측정변인들 사이에 관련성을 평가하였다. 연구 결과 집단 간 수축기혈압(p<.05), 인슐린(p<.05), HOMA-IR(p<.05), VO2max(p<.05), 다리지방률(p<.05)에서 유의한 차이가 나타났다. 전체 집단에서 QTc interval은 BMI(r=.540, p=.011), 수축기혈압(r=.473, p=.030)와 유의한 관련을 나타냈다. 또한, QTc interval은 CT를 이용하여 측정한 총 지방면적(r=.497, p=.022) 및 복부내장 지방면적(r=.520, p=.014)과 유의한 상관을 나타내었으며 DEXA를 이용하여 측정한 다리지방률(r=.529, p=.014) 및 전신지방률(r=.450, p=.041)과도 유의한 관련성이 확인되었다. QTc interval과 VO2max 사이에도 유의한 상관(r=­.614, p=.003)이 나타났으며 이는 BMI를 보정한 편 상관분석(r=.480, p=.032)에서도 관련성이 확인되었다. 이상의 결과를 종합해 볼 때 연장된 QTc interval은 정상 QTc interval을 가진 집단에 비해 내장지방축적과 인슐린 저항성 그리고 고혈압 요인들과 관련이 되어 있으며, 또한 최대유산소능력과도 밀접한 관련성을 가지는 것으로 나타났다. 차후에는 비만치료 및 유산소운동능력 향상에 초점을 둔 트레이닝을 통해 연장된 QTc interval의 변화를 파악하고 그 관련 변인을 탐색하는 것이 필요할 것으로 판단된다. The purpose of this study was to examine the relationship between QTc interval and maximal oxygen consumption(VO2max) and body fat distribution in middle-aged men. Abnormal subjects (QTc interval, ≥440ms, n=10) and normal subjects(≤430ms, n=11) using QTc interval based on the Bazzet``s equation were involved in the study. After overnight fasting, blood and blood pressure were measured. Abdominal fat area and regional fat compartment were measured by computed tomography(CT) and dual-energy X-ray absorptiometry(DXA), respectively. For VO2max, the subjects underwent a maximal graded exercise test on a cycling ergometer. Abnormal group was significantly higher in SBP, basal insulin, HOMA-IR, and leg fat compared with normal. There was a significant relationship(r=­.614, p=.03) between QTc interval and VO2max in all subjects. Also, partial correlation analysis showed a significant relationship(r=.480, p=.032) between the QTc interval and VO2max. Having a QTc interval outside normal range significantly worsened risk parameters for metabolic syndrome, in particular blood pressure and insulin resistance. Moreover, QTc interval was strongly correlated with cardiorespiratory fitness in middle-aged men. This study indicates that further study will be needed to assess the exercise training effects on QTc interval.

저항운동 트레이닝이 흡연남성의 심장 자율신경시스템에 미치는 영향

김맹규 ( Maeng Kyu Kim ),김춘섭 ( Choun Sub Kim ) 한국스포츠정책과학원(구 한국스포츠개발원) 2015 체육과학연구 Vol.26 No.4

본 연구는 8주간의 고강도 및 저강도 저항트레이닝이 습관성 흡연자의 자율신경에 미치는 영향을 조사하기 위한 목적으로 수행되었다. 건강하고 젊은 남성 흡연자 28명을 대상으로 통제군(Control), 저강도 저항트레이닝군(LRT, 50% 1RM, 10-rep, 2-set), 고강도 저항트레이닝군(HRT, 70% 1RM, 10-rep, 2-set)으로 각각 무작위 배정하였으며, 모든 실험군은 평소 흡연습관을 유지한 상태로 8주 동안 실시하되, 운동군은 저항트레이닝 머신을 이용하여 상체 4종목, 하체 4종목의 전신 저항트레이닝을 수행하였다. 최소 20분간의 안정 후 처지 전.후 신체조성을 포함한 혈역학적 변인을 측정하였고, 심장의 자율신경계 측정 및 등속성기기를 이용하여 슬관절(부하속도 60, 180, 240 deg/sec)의 굴곡과 신전에 대한 관절의 근력(peak torque, 최대회전력)의 변화를 평가하였다. 결과는 다음과 같다. 8주간의 저항트레이닝은 통제군에 비해 운동군에서 등속성 근력 및 1RM의 유의한 증가를 가져왔으며, 심박변이도의 spectral 지표 중 부교감신경활동을 반영하는 HF가 통제군에 비해 HRT에서 유의하게 증가하였다. 또한 교감-미주신경 밸런스에서 교감신경활동 우세를 반영하는 LF nu는 통제군에 비해 HRT에서 유의하게 감소한 반면, 부교감신경활동 우세를 반영하는 HF nu는 통제군에 비해 HRT에서 유의하게 증가하였다. HF, HF nu, LF nu의 변화량은 등속성 근력의 변화량과 정적 관련성을 나타내었다. 이상의 결과는 젊은 흡연남성에 있어서 8주간의 고강도 저항트레이닝은 근력의 증가와 함께 안정 시 교감신경억제 및 부교감신경활성화를 통해 자율신경밸런스의 향상에 기여하였음을 시사한다. 따라서 근력향상을 동반한 고강도의 저항트레이닝 프로그램은 담배흡연으로 인한 교감신경 활성화 및 부교감신경저하 즉 자율신경불균형의 개선에 도움이 될 것으로 판단된다. The purpose of this study is to investigate the influence of resistance training with different exercise intensities on heart rate variability(HRV) in habitual smokers. Twenty-eight healthy young smokers participated in this study were randomly divided into three groups; CON(control), LRT(low-intensity resistance training; 50% 1RM), and HRT(high-intensity resistance training; 70%1RM), respectively. LRT and HRT groups performed an 8-week resistance training(4 upper- and lower body exercises) using weight training machines, whereas CON group maintained their regular activities. All groups were evaluated basal body composition, hemodynamic parameters, HRV as autonomic nervous function, and muscular strength (1RM and isokinetic test) before and after the 8-week training. To assess the effect of 8-week training with different intensities on autonomic regulation, time and frequency domain indices of HRV were calculated from 5min R-R interval recording. As results, both LRT and HRT groups increased baseline 1RM and isokinetic strength compared to CON group. Meanwhile, high-frequency power reflecting parasympathetic activity was significantly increased in HRT compared to CON group. In addition, normalized low frequency power(LF nu) indicating a shift of sympathovagal balance towards sympathetic predominance significantly decreased while normalized high frequency power(HF nu) which reflects vagal predominance significantly increased in HRT compared to CON group. Furthermore, improved cardiac autonomic regulation and parasympathetic activation had significant association with increased muscular strength. Overall, the 8-week training has enhanced muscular strength in both training groups, particularly autonomic balance improved in young habitual smokers with high intensity resistance training.

운동 후 심박회복에 따른 자율신경계의 경시적 조절: 팔과 다리의 국소적인 비교

김맹규 ( Maeng Kyu Kim ),김춘섭 ( Choun Sub Kim ) 한국스포츠정책과학원(구 한국스포츠개발원) 2015 체육과학연구 Vol.26 No.2

본 연구는 상·하지의 국소적 신체부위를 이용한 일회성 유산소 운동의 post-exercise recovery(REC)에서 나타나는 심박변이도(heart rate variability, HRV)의 차이를 살펴봄으로써 자율신경 향상을 위한 효율적 운동모드를 탐색하기 위한 목적으로 수행되었다. 건강한 젊은 남성 11명을 대상으로 무작위교차설계를 통해 동일한 강도의 여유심박수(50% heart rate reserve) 하에서 30분 간 Arm ergometer(AE) 및 Legcycling(LE)의 평형상태운동(steady state exercise) 후 REC1(0~10 min), REC2(10~20 min), REC3(20~30 min)의 세 구간에서 R-R intervals를 획득하여 시간 및 주파수와 비선형지수(Poincareplot)를 산출하였다. 결과는 다음과 같다. HRV의 시간영역지수를 이용해 운동모드 간의 차이를 평가한 결과post-exercise recovery에서 AE 수행 후에 비해 LE 수행 후 ANS 조절능(SDNN) 및 PNS 재활성화(rMSSD)가 높게 나타났다. Poincare plot을 이용해 운동모드 간의 차이를 분석한 결과 post-exerciserecovery에서 AE 수행 후에 비해 LE 수행 후 ANS 조절능(SD2) 및 PNS 재활성화(SD1)를 반영하는 HRV parameters의 회복률이 높게 나타났다. Spectral power 분석에서 부교감신경 재활성화를 독립적으로 반영하는 HF가 초기 post-exercise recovery(REC1)에서 AE 수행 후에 비해 LE 수행 후 유의하게 증가하였으며, 교감-미주신경 밸런스(sympathetic-vagal balance)의 교감신경 활성화를 반영하는 지수인LF/HF ratio 와 LF nu는 AE 수행 후 유의하게 높은 수치를 나타낸 반면 부교감신경 활성화를 반영하는 지수인 HF/TP ratio와 HF nu는 LE 수행 후 유의하게 높은 수치를 나타내었다. 이상의 결과는 심박수를 일치시킨 다리의 국소적 운동이 팔의 국소적 운동에 비해 운동 후 부교감신경 재활성화가 신속하게 나타난다는 것을 암시한다. 따라서 상지에 비해 하지를 이용한 유산소 운동은 운동 후 부교감 재활성화 및 교감 활동의 빠른 억제를 통해 자율신경계의 조절에 긍정적인 영향을 미치며, 운동 후 자율신경회복이 심장사고(events)와 관련한다는 점에서 보다 안전하고 효율적인 운동법이라 판단된다. Although delayed heart rate recovery (HRR) and impaired autonomic nerve system (ANS) modulation after acute exercise are related with cause of cardiovascular disease (CVD) and mortality, studies evaluating ANS changes with local exercise are still unsatisfied. Thus, this study aimed at investigating the modulation of ANS-related parameters, followed by upper or lower body exercise. Eleven male without cardiovascular and orthopedic diseases measured basic body composition, resting blood pressure (BP), and heart rate variability (HRV). This study based on randomized cross-over design; AE composed with arm-ergometer, and LE involved with leg cycling. Participants had at least one week wash-out between each exercise, also there was no cool-down after exercise. All sessions were performed with intensity of 50 % target heart rate for 30 min. With measurement of Rating of perceived exertion (RPE) during every 10 min, HRV was measured Kubios HRV software using R-R intervals collected with Polar RS800CX in post-exercise recovery (for 30 min). As a result, heart rate (HR) and RPE were same (p > 0.05) through the experiment. As results of this study, SDNN and rMSSD in time domain on LE were higher than on AE during post-exercise recovery. When LE compared with AE used by Poincare plot, both parasympathetic reactivation (SD1) and autonomic nerve regulation (SD 2) on LE were higher than AE. Immediately after submaximal exercise, the high-frequency component on LE was significantly greater compared to AE. Also, the LF/HF ratio and LF nu reflecting sympathetic activity were higher on AE than LE. In contrast, the HF/TP ratio and HF nu reflecting vagal tone were greater on LE than AE. In conclusion, this study suggested regional lower body exercise recovers more sufficient than regional upper body exercise after submaximal aerobic exercise at same HR. Local exercise like leg cycling needs a careful approach to apply for accurate exercise prescription and effective training.

폐 기능 및 운동수행력 증진을 위한 비 확장기의 효용성

김동규 ( Dong-kyu Kim ),김맹규 ( Maeng-kyu Kim ) 한국운동생리학회 2021 운동과학 Vol.30 No.4

PURPOSE: This study aimed to examine changes in pulmonary function induced by an internal nasal dilator (IND) and to determine whether an IND enhances exercise performance. METHODS: Young, healthy men (n=13) were randomly assigned either an IND or control (CON) session to perform a pulmonary function test (PFT). All participants then completed treadmill exercise tests that consisted of maximal and submaximal running with or without an IND. RESULTS: Some variables of PFTs were increased in men that used INDs compared to those in the CON group (p<.05, respectively). There was a significant difference between sessions in energy cost during the running test (65% VO_2max) (p<.05). In the IND group, respiratory muscle fatigue during exercise was lower, and relaxation of respiratory muscles after exercise was faster, as compared with the CON group (p<.05). CONCLUSIONS: IND may contribute to improvements in pulmonary function. Furthermore, INDs may reduce energy costs and respiratory muscle fatigue during submaximal exercise by maintaining nasal breathing and facilitating respiratory muscle relaxation after maximal exercise tests.

8주간의 비대면 필라테스 운동이 체간 근육의 구조 및 질적 변화와 기능적 움직임에 미치는 영향

김아영(Kim, Ah-Young),조현덕(Jo, Hyeon-Deok),김맹규(Kim, Maeng-Kyu) 한국코칭능력개발원 2022 코칭능력개발지 Vol.24 No.5

단기간의 흡연중단과 유산소운동이 자율신경조절에 미치는 영향

김춘섭(Choun-Sub Kim),김맹규(Maeng-Kyu Kim) 한국생활환경학회 2014 한국생활환경학회지 Vol.21 No.3

The purpose of this study was to investigate the effects of 3-day smoking cessation (SC) and/or aerobic exercise (AE) on the autonomic nerve system (ANS) in healthy male smokers. Seven subjects participated in an AE (session A), SC (session B), and SC + AE (session C) through randomized crossover design, consisting of 60% of heart rate reserve, 60 min/day during consecutive 3-day in healthy male smokers. After overnight fasting, the ANS activities were assessed using power spectral analysis of heart rate variability (HRV) at resting and post period. Exhaled carbon monoxide (CO) to confirm smoking status and forced vital capacity (FVC) to test pulmonary function were also measured before and after the session. Although each session does not affect FVC, CO was significantly reduced in sessions B and C, respectively (p<.05). Mean HR was significantly decreased in the session A and C, but not in the session B. The HRV parameters in session C, but not session A and B showed increased high frequency and increased SDNN, pNN50, RMSSD, respectively (p<.05). In this study, short-term aerobic exercise with smoking cessation led to a significant increase in the parasympathetic activity, suggesting these treatments will be an effective intervention for young smokers.

전자담배흡연이 심장자율신경조절에 미치는 반응

김춘섭(Choun Sub Kim),김맹규(Maeng Kyu Kim) 한국생명과학회 2018 생명과학회지 Vol.28 No.5

전 세계적으로 담배흡연자의 심혈관 위험 감소와 금연을 위한 대안으로 전자담배 이용이 급속하게 확산되고 있지만 니코틴을 포함한 잠재적 유해화합물을 함유한 전자담배의 심혈관 효과는 불분명하다. 본 연구는 전자담배 사용에 따른 심장자율신경조절 변화를 관찰하고 급성적인 교감신경흥분효과 및 부교감신경활동 저하 반응을 궐련담배 흡연과 직접 비교하려는 목적으로 수행되었다. 41명의 젊고 건강한 흡연남성들을 대상으로 자료 분석을 수행하였으며, 무작위 교차 설계에 의해 1주의 wash-out period를 적용하여 전자담배와 궐련담배 세션이 각각 실시되었다. 전자담배는 흡연 시를 포함한 흡연 후 5분까지, 궐련담배의 경우 흡연 시 및 흡연 후 최대 30분까지 교감신경활성화 및 부교감신경 감소가 관찰되었다. 두 제품 간 비교에서, 흡연 시를 포함한 흡연 후 30분 동안의 HRV 분석에서 전자담배는 궐련담배에 비해 비교적 교감신경흥분효과 및 부교감신경저하에서 적은 변화수준 및 단시간 변화를 제공하는 것으로 나타났다. 이상의 결과들은 비록 전자담배가 궐련담배에 비해 심장자율신경조절에서 상대적으로 완화된 효과를 제공한다고 할지라도 전자담배 내 니코틴 및 잠재적 위험요인들을 고려해 볼 때 급성적인 교감신경흥분작용 및 부교감신경의 저하를 야기함으로 과도한 사용에 주의가 요구된다. This study aims to observe changes in heart-rate variability (HRV) indices induced by e-cigarette and conventional-cigarette smoking and to compare the differences in acute cardiac autonomic regulation. All participants (n=41) were exposed to both e-cigarette smoke (ES) and conventional cigarette smoke (CS) in a randomized crossover trial. HRV analysis was performed during each smoking session based on a recorded r-r interval 10 minutes before smoking and at specified recovery periods (REC1, 0-5 min; REC2, 5-10 min; REC3, 10-15 min; REC4, 15-20 min; REC5, 20-25 min; and REC6, 25-30 min). ES led to a significantly increased cardiac sympathetic index (LF/HF ratio) compared with the baseline, and it shifted the sympathovagal balance toward sympathetic predominance, including reduction in the complexity of the interbeat interval (SampEn). In REC1 after ES, only decreases of parasympathetic indices such as rMSSD, pNN50, HF, and SD1 were indicated. CS sessions produced not only an increased LF/HF ratio during smoking and recovery periods (REC1 and REC4) but also enhanced sympathetic predominance on autonomic balance during smoking and recovery periods (REC1, REC2, and REC4). In the CS trials, parasympathetic indices of time and non-linear analysis (rMSSD, pNN50, and SD1) were decreased during smoking and in REC1 to REC5. SampEn was also reduced during smoking and REC1 to REC4. Acute sympathoexcitatory effects induced by e-cigarette use produced statistically significant results. Parasympathetic withdrawal after smoking suggests that e-cigarettes may cause increased cardiovascular risk.

편심성 운동 후 상완이두근의 국소부위 간 기계적 속성의 차이

김춘섭 ( Choun-sub Kim ),김맹규 ( Maeng-kyu Kim ) 한국운동생리학회 2021 운동과학 Vol.30 No.3

PURPOSE: This study aimed to examine the effects of eccentric exercise (ECC) on the indices of mechanical properties together with markers of exercise-induced muscle damage (EIMD) in different sites of the biceps brachii (BB) muscle. METHODS: ECC using an elbow joint was performed in 13 non-trained, college men. Global symptoms of EIMD were identified through changes in muscle soreness and serum creatine kinase (CK) activity, including muscle function following ECC. To evaluate regional EIMD, muscle swelling and tenderness as well as muscular echo intensity were measured at distal (4 cm above the elbow joint) and middle (30% of the distance from the antecubital crease to the acromion) sites within the BB muscle. A handheld myotonometer was used to estimate changes in mechanical properties, that is, oscillation frequency (F), dynamic stiffness (S), and relaxation time (R), of BB muscles after ECC. RESULTS: A significant difference in the major markers of EIMD, such as muscle soreness and serum CK activity, along with parameters of muscle function, was observed after ECC compared to baseline. Although all indirect markers of regional muscle damage demonstrated meaningful differences between before and after ECC, no statistically significant interaction between the distal and middle sites was observed in any of the markers. After ECC, both distal and middle sites showed significant changes in F, S, and R, but no statistical differences in changes in muscle mechanical properties were observed between localized muscle sites within BB muscles. CONCLUSIONS: Changes in mechanical properties, including regional muscle damage, seem to be uniformly influenced by different anatomical locations within the BB muscle, such as elbow flexors, following ECC.

남자흡연대학생의 비만과 심장자율신경조절의 관련성

김춘섭(Choun Sub Kim),김맹규(Maeng Kyu Kim) 한국응용과학기술학회 (구.한국유화학회) 2019 한국응용과학기술학회지 Vol.36 No.1

본 연구는 담배흡연자에서 비만과 심장자율신경조절의 관련성 규명을 목적으로 수행되었다. 의료기록 및 외관상 건강한 총 85명의 남자 대학생 흡연자들을 대상으로 자료를 수집하였으며, 모든 참가자들의 안정 시 심장자율신경조절 평가를 위해 단기간 표준프로토콜에 따른 심박변이도(heart rate variability, HRV) 지표들을 산출하였다. 한편 체질량지수, 체지방률, 허리둘레 및 허리/엉덩이 둘레비는 표준 비만지표로서 활용되었다. 연구결과 허리/엉덩이 둘레비를 기준으로 분류된 상위집단은 하위집단에 비해 부교감신경활동을 반영하는 HRV의 rMSSD, pNN50, HF 및 SD1에서 유의하게 낮은 값을 나타내었다. 그러나 HRV의 교감신경활동지수 LF/HF에서는 집단 간 통계적 차이가 없었다. 또한 상관분석 결과 시간, 주파수 및 비선형영역의 HRV 부교감신경 지수들이 체질량지수와 관련하지 않는 반면 허리둘레, 허리/ 엉덩이 둘레비 및 체지방률과 같은 비만지표들과는 유의한 상관관계를 나타내었다. 특히 허리둘레와 체지방률에 비해 허리/엉덩이 둘레비가 부교감신경활동과 더 밀접하게 관련하는 경향을 나타냈다. 이상의 결과들은 남자 대학생 흡연자들에서 전반적인 비만도를 반영하는 체질량지수와는 독립적으로 중심부 비만이 심장부교감신경 저하와 관련하는 주된 상관 요인임을 뒷받침한다. This study aimed to explore the association between obesity index and heart rate variability (HRV) in college-aged male smokers. A total of 85 male college students (> 10 cigarettes per day for at least 3 years) were participated in this study. According to a standardized protocol, body mass index (BMI), percent body fat (%BF), waist circumference (WC), and waist-to-hip ratio (WHR) were taken as obesity indices. Resting r-r interval was monitored for HRV analysis as an indicator of cardiac autonomic regulation. Compared with low WHR subjects, high WHR subjects had significantly lower values of rMSSD, pNN50, HF, and SD1, suggesting decreased parasympathetic activity. No such differences in LF/HF ratio were found between the WHR-based subgroups. Bivariate correlation analysis showed that obesity indices of WC, WHR, and %BF were significantly associated with rMSSD, pNN50, HF, and SD1, with a tendency for correlation coefficient to be higher with WHR than with WC or %BF. No significant association was found between BMI and HRV parameters indicative of parasympathetic activity. This study suggest that central obesity is significantly associated with decrease in parasympathetic activation, independent of BMI as an indicator of obesity, in male college smokers.

운동 중 심박변동성 반응에 대한 안정 시 심박변이도의 관여

김춘섭 ( Choun-sub Kim ),김맹규 ( Maeng-kyu Kim ) 한국운동생리학회(구 한국운동과학회) 2021 운동과학 Vol.30 No.1

PURPOSE: Although resting heart rate variability (HRV) and chronotropic responses (CR) are common prognostic factor for cardiovascular disease, it is still unknown whether relationships between two variables are affected by exercise. The current study was aimed to identify correlations between resting cardiac autonomic regulation and graded exercise test-derived CR. METHODS: We recruited apparently healthy men college students aged between 20 and 29 years (n=46). They were assigned to Low-and High groups which have been determined for medians involved in resting heart rate (HR) or HRV indices such as rMSSD, HF, and LF/HF ratio, respectively. CR and post-exercise heart rate recovery (HRR) were calculated from HR fluctuations during and after symptom-limited graded exercise test using the Bruce protocol. RESULTS: In HRR, there were no significant differences between all Low and High groups separated by resting levels of HR or HRV indices. However, all Low groups assigned according to resting cardiac vagal-related HRV indices such as rMSSD and HF showed significantly lower CR levels than those of High groups, respectively. Moreover, CRs derived from stage 1-3 of Bruce protocol were positively correlated resting rMSSD and HF levels, respectively. CONCLUSIONS: The findings of the current study suggest that resting levels of cardiac vagal-related HRV indices may have an impact on CR derived from a graded exercise test, as well as there is a significant association between resting cardiac vagal activity and HR response during incremental exercise.