Laaksonen Marko S, Kalliokoski Kari K, Kyröläinen Heikki, Kemppainen Jukka, Teräs Mika, Sipilä Hannu, Nuutila Pirjo, Knuuti Juhani
Turku Positron Emission Tomography Centre, University of Turku, FIN-20521 Turku, Finland.
Am J Physiol Heart Circ Physiol. 2003 Mar;284(3):H979-86. doi: 10.1152/ajpheart.00714.2002. Epub 2002 Nov 21.
The effects of dynamic and intermittent isometric knee extension exercises on skeletal muscle blood flow and flow heterogeneity were studied in seven healthy endurance-trained men. Regional muscle blood flow was measured using positron emission tomography (PET) and an [(15)O]H(2)O tracer, and electromyographic (EMG) activity was recorded in the quadriceps femoris (QF) muscle during submaximal intermittent isometric and dynamic exercises. QF blood flow was 61% (P = 0.002) higher during dynamic exercise. Interestingly, flow heterogeneity was 13% (P = 0.024) lower during dynamic compared with intermittent isometric exercise. EMG activity was significantly higher (P < 0.001) during dynamic exercise, and the change in EMG activity from isometric to dynamic exercise was tightly related to the change in blood flow in the vastus lateralis muscle (r = 0.98, P < 0.001) but not in the rectus femoris muscle (r = -0.09, P = 0.942). In conclusion, dynamic exercise causes higher and less heterogeneous blood flow than intermittent isometric exercise at the same exercise intensity. These responses are, at least partly, related to the increased EMG activity.
我们对7名健康的耐力训练男性进行了研究，以探讨动态和间歇性等长伸膝运动对骨骼肌血流及血流异质性的影响。使用正电子发射断层扫描（PET）和[（15）O]H（2）O示踪剂测量局部肌肉血流，并在次最大强度间歇性等长运动和动态运动期间记录股四头肌（QF）的肌电图（EMG）活动。动态运动期间QF血流高出61%（P = 0.002）。有趣的是，与间歇性等长运动相比，动态运动期间血流异质性降低了13%（P = 0.024）。动态运动期间EMG活动显著更高（P < 0.001），并且从等长运动到动态运动时EMG活动的变化与股外侧肌血流变化密切相关（r = 0.98，P < 0.001），但与股直肌血流变化无关（r = -0.09，P = 0.942）。总之，在相同运动强度下，动态运动比间歇性等长运动引起的血流更高且异质性更低。这些反应至少部分与EMG活动增加有关。
