以超快超音波探討不同強度阻力訓練對中心動脈與肌肉硬度之影響

Abstract

目的：本研究旨在探討不同強度阻力訓練對肌肉與血管硬度之影響，並了解肌肉和血管硬度是否有關聯。方法：本研究招募21位男性受試者參與此重複量數實驗，於肱二頭肌最大肌力測試後，隨機分配至40%或80%1 RM，操作5組10下反覆次數，於運動前後使用超音波測量肌肉形變與頸動脈管徑變化，並使用非侵入性血管監控儀器測量血管指標。結果：80% 1RM高強度阻力運動造成肌肉形變顯著降低（0.10±0.01公分/秒）、曲線下面積顯著減少（239±20平方公分），而無論40% 1RM或80% 1RM的強度，皆造成baPWV顯著增加，分別為1200±20公分/秒和1232±21公分/秒，進一步依受試者一週有氧時間分組，發現阻力組的血管管徑變化較有氧組顯著變小（-0.16±0.11毫米），顯示血管變得顯著僵硬。結論：強度與肌肉硬度存在正相關，但肌肉硬度與局部血管硬度並無相關。同時，不同強度的阻力訓練皆導致周邊血管硬化，且依照一週有氧時間，影響不同區域的血管硬化效果。

Purpose: The purpose of this study was to examine the effect of different intensity on muscular and vascular stiffness and whether there is a relationship between muscular and vascular stiffness. Methods: There were 21 males recruited and randomly assigned into this study. After a maximum strength test of bicep brachial, subjects performed an acute bout of bicep curl for 5 sets 10 reps with intensity of 80% and 40% 1RM prospectively. We measured the muscle strain and carotid diameter with ultrasound and vascular index with non-invasive vascular monitoring machine before and after the exercise. Results: High-intensity resistance training resulted in a decrease in muscle strain rate (0.10±0.01 cm/s) and AUC (239±20 cm2). In addition, low and high intensity both elicited an increase in baPWV (1200±20 cm/s and 1232±21 cm/s). Furthermore, vascular stiffness in resistance-only group was higher than combined exercise group (resistance+aerobic exercise) after subgrouping by the time spent with aerobic according to ACSM guidelines. There was a significant decrease in vascular diameter in resistance-only group (-0.16±0.11mm), suggesting vessels were stiffened following the acute bout of resistance exercise. Conclusion: There is positive relationship between exercise intensity and muscle stiffness, yet there is no relationship between muscle and vascular stiffness parameters we measured. Resistance exercise of high intensity would likely to increase peripheral vascular stiffness and it appeared to be dependent by aerobic time.