Svedenhag J, Wallin B G, Sundlöf G, Henriksson J
Acta Physiol Scand. 1984 Apr;120(4):499-504. doi: 10.1111/j.1748-1716.1984.tb07413.x.
The effect of physical training on muscle sympathetic activity (MSA) was studied by comparing resting levels of MSA in 8 well-trained racing cyclists and in 8 age-matched untrained subjects (mean age 22 yrs). In addition, MSA was determined for 5 untrained subjects before and after an 8-week training program on cycle ergometers (training group). Recordings were made from the peroneal nerve at the knee with the subject in recumbent position. The well-trained cyclists were characterized by a clearly higher maximal oxygen uptake (VO2 max) and lower heart rate at submaximal exercise (180 W) than their untrained counterparts. These variables were also significantly changed with training in the training group. In contrast, there were no training-related effects on MSA. Thus, MSA expressed as either the number of sympathetic bursts/100 heart beats (+2%, NS) or bursts/min (-10%, NS) did not differ between the well-trained cyclists and the untrained controls. Furthermore, no changes in MSA occurred with training in the training group (bursts/100 heart beats: +8%, NS; bursts/min -2%, NS). Individual variations in MSA were large and independent of training state. It is concluded that differences in physical conditioning do not account for the large inter-individual differences in MSA in resting man.
通过比较8名训练有素的自行车赛车手和8名年龄匹配的未训练受试者（平均年龄22岁）的肌肉交感神经活动（MSA）静息水平，研究了体育锻炼对MSA的影响。此外，还对5名未训练受试者在进行为期8周的自行车测力计训练计划之前和之后的MSA进行了测定（训练组）。受试者仰卧位时，在膝盖处的腓总神经进行记录。训练有素的自行车赛车手的特征是，与未训练的同龄人相比，其最大摄氧量（VO2 max）明显更高，在次最大运动量（180 W）时心率更低。训练组中这些变量也因训练而发生了显著变化。相比之下，训练对MSA没有相关影响。因此，以交感神经爆发次数/100次心跳（+2%，无显著性差异）或爆发次数/分钟（-10%，无显著性差异）表示的MSA，在训练有素的自行车赛车手和未训练的对照组之间没有差异。此外，训练组在训练后MSA没有变化（爆发次数/100次心跳：+8%，无显著性差异；爆发次数/分钟：-2%，无显著性差异）。MSA的个体差异很大，且与训练状态无关。得出的结论是，身体状况的差异并不能解释静息状态下人体MSA存在的个体间巨大差异。
