Haralambie G, Berg A
Eur J Appl Physiol Occup Physiol. 1976 Dec 6;36(1):39-48. doi: 10.1007/BF00421632.
In eight groups of healthy male athlets, aged 19-44 years, serum urea, alpha-amino nitrogen and free tyrosine were determined before and after physical exercise of different duration. Exercise was competitional running, skiing, march or bicycle ergometer work, its duration between 15 and 765 min. The results were compared with previous data from this laboratory and those of other authors. After about 60-70 min of exertion, there is a significant fall in serum amino nitrogen and a rise in urea and free tyrosine; the magnitude of these changes correlated well to the duration of exercise. Likewise, there is a significant correlation between increase in serum urea and decrease in amino nitrogen. The observed changes strongly suggest an increased breakdown of nitrogen-containing compounds during prolonged exercise.
在八组年龄为19 - 44岁的健康男性运动员中，测定了不同时长体育锻炼前后的血清尿素、α - 氨基氮和游离酪氨酸。锻炼项目为竞技跑步、滑雪、行军或自行车测力计运动，时长在15至765分钟之间。将结果与该实验室之前的数据以及其他作者的数据进行了比较。在大约60 - 70分钟的运动后，血清氨基氮显著下降，尿素和游离酪氨酸升高；这些变化的幅度与运动时长密切相关。同样，血清尿素的增加与氨基氮的减少之间存在显著相关性。观察到的变化强烈表明在长时间运动期间含氮化合物的分解增加。
