Thompson P D, Lewis S, Varady A, Areskog N, Popp R, Debusk R, Haskell W
Med Sci Sports Exerc. 1981;13(5):303-9.
We have recently reported improved exercise performance with untrained limbs in 10 men after 11 wk of either arm (N = 5) or leg (N = 5) endurance training. To examine the changes in cardiac function produced by short-term training, we used echocardiography to measure cardiac function at rest, and systolic time intervals (STIs) to measure cardiac function during trained and untrained limb exercise. We repeated all studies after autonomic blockade with atropine and propranolol in order to observe non-autonomic changes in cardiac function. Training had little effect on cardiac size or performance at rest, although with autonomic blockade, cardiac mass increased in the leg-training group and resting left ventricular ejection time (LVET) was prolonged when the two training groups were combined. During submaximal exercise with both trained and undrained limbs and at similar heart rates before and after training, LVET for the combined groups was increased with and without autonomic blockade. This increase in LVET is most consistent with an increased cardiac stroke volume. Short-term endurance training appears to result in improved exercise cardiac function that is in part independent of altered autonomic control or adaptations in trained skeletal muscle.
我们最近报道，10名男性在进行11周的上肢（N = 5）或下肢（N = 5）耐力训练后，未经训练的肢体的运动表现得到改善。为了研究短期训练对心脏功能的影响，我们使用超声心动图测量静息时的心脏功能，并使用收缩期时间间期（STIs）测量训练肢体和未训练肢体运动时的心脏功能。在用阿托品和普萘洛尔进行自主神经阻滞之后，我们重复了所有研究，以观察心脏功能的非自主神经变化。训练对静息时的心脏大小或功能影响很小，尽管在自主神经阻滞后，腿部训练组的心脏质量增加，并且将两个训练组合并时静息左心室射血时间（LVET）延长。在训练肢体和未训练肢体进行次最大运动期间，以及训练前后心率相似时，合并组的LVET在有或没有自主神经阻滞的情况下均增加。LVET的这种增加与心搏量增加最为一致。短期耐力训练似乎可改善运动时的心脏功能，这部分独立于自主神经控制的改变或训练的骨骼肌的适应性变化。
