局部與全身性等長阻力訓練的心血管效益：運動後的壓力反應及長期適應

Benefits of local and whole-body isometric resistance training on cardiovascular system: Stress responses and long-term adaptation of exercise

緒論：等長阻力訓練（isometric resistance training, IRT）被指出改善血壓的效果優於耐力與動態阻力訓練，但現有結果僅限於上肢及下肢的局部肌群運動，不同肢段運動的急性與長期介入效益仍有待釐清。因此，本研究旨在探討局部上肢、軀幹、下肢及全身性等長阻力訓練的急性心血管壓力反應與長期適應效果。方法：招募42名無規律運動習慣之過重與肥胖年輕成人（男性22名；女性20名），隨機分派至等長握力組（isometric handgrip group, IHG；11名）、等長捲腹組（isometric curl-up group, ICG；12名）、等長倚牆蹲組（isometric wall-squat group, ISG；10名）及全身性等長運動組（whole body isometric exercise group, WIG；9名），介入為期4週，每週3次的等長運動。並於第1及12次運動評估運動前、運動後立即、30分鐘及60分鐘（P0、P30、P60）急性心血管變化；介入前（第0週）與後（第5週）評估長期適應變化。結果：急性結果顯示，第1次運動ICG、ISG及WIG於P0時間點SBP及DBP顯著增加（p＜.05）；ISG於P0時間點MAP顯著增加（p＜.05）；各時間點組間皆無顯著差異（p＞.05）。第12次運動IHG、ISG及WIG於P0時間點SBP顯著增加（p＜.05）；ISG於P0時間點DBP及MAP顯著增加（p＜.05）；各時間點組別間皆無顯著差異（p＞.05）。HR結果顯示，ISG及WIG於P0時間點皆顯著增加（p＜.05）。長期血壓的結果顯示，WIG介入後SBP顯著降低了6.6 mmHg；ICG介入後DBP顯著降低了8.5 mmHg；ISG介入後DBP及MAP分別顯著降低了7.9 mmHg及7.4 mmHg；而IHG皆無顯著降低。結論：等長阻力運動是一項安全、便於實施，長期介入能有效控制血壓的運動方式，且並不會造成單次運動後過高的心血管壓力反應。

Introduction: Isometric resistance training (IRT) has been associated with better blood pressure reduction effects than endurance training or dynamic resistance training. However, studies of IRT have been limited to isolated exercises involving the upper and lower limbs. The acute responses and long-term cardiovascular benefits of combining whole-body exercises with limb isolation exercises remain unclear. This study aimed to investigate the cardiovascular stress responses and long-term adaptation following IRT focused on the upper limbs, trunk, lower limbs, and whole-body. Methods: A total of 42 overweight or obese college students were randomly assigned to the following interventions: isometric handgrip (IHG; N = 11), isometric curl-up (ICG; N = 12), isometric wall-squat (ISG; N = 10), and whole-body isometric exercise (WIG; N = 9). All groups exercised 3 times/week for 4 weeks. Acute cardiovascular stress responses were measured before and 0, 30, and 60 min after (pre, P0, P30, and P60, respectively) the first and twelfth exercise sessions. Long-term adaptation was assessed before (week 0) and after (week 5) intervention. Results: Acute responses measured during the first session showed significantly increased systolic (SBP) and diastolic blood pressure (DBP) at P0 following ICG, ISG, and WIG compared with pre (p ＜ .05). Mean arterial pressure (MAP) increased significantly at P0 following ISG compared with pre (p ＜ .05). During the twelfth week, significantly increased SBP at P0 was observed following IHG, ISG, and WIG compared with pre (p ＜ .05); DBP and MAP increased significantly at P0 following ISG compared with pre (p ＜ .05). Both ISG and WIG induced significantly increased heart rates at P0 compared with pre (p ＜ .05). Long-term adaptation was indicated by significantly reduced SBP (-6.6 mmHg) after WIG intervention (p ＜ .05), significantly reduced DBP (-8.5 mmHg) after ISG intervention (p ＜ .05), and significantly reduced DBP and MAP (-7.9 and -7.4 mmHg, respectively) after ISG intervention compared with before intervention (p ＜ .05). No significant changes were observed after the IHG intervention (p ＞ .05). Conclusions: Single isometric resistance exercises do not cause excessive cardiovascular stress, and IRT is a safe, user-friendly, and effective long-term intervention for improving blood pressure control.