Department of Bioenergetics and Physiology of Exercise, Medical University of Gdansk, 80-210 Gdansk, Poland.
Department of Health and Life Sciences, Gdansk University of Physical Education and Sport, 80-336 Gdansk, Poland.
Nutrients. 2023 Jun 30;15(13):2981. doi: 10.3390/nu15132981.
Changes in serum concentration of methylarginines and amino acids after exercise are well documented, whereas the effects of exercise applied together with fasting are still debated and not thoroughly studied. Thus, we hypothesised that alterations in methylarginines such as ADMA, SDMA and L-NMMA might be responsible for decreased exercise performance after 8 days of fasting. Additionally, we propose that conditions in which the human body is exposed to prolonged fasting for more than a week elicit a distinctly different response to exercise than after overnight fasting. A group of 10 healthy men with previous fasting experience participated in the study. The exercise test was performed until exhaustion with a gradually increasing intensity before and after the 8-day fast. Blood samples were collected before and immediately after exercise. ADMA, SDMA, L-NMMA, dimethylamine and amino acids were analysed in serum samples by ID-LC-MS/MS. SDMA, L-NMMA and dimethylamine significantly decreased after 8 days of fasting, whereas ADMA did not change. BCAA, Phe, alanine and some other amino acids increased after fasting. Exercise-induced changes in amino acids were distinct after an 8-day fast compared to overnight fasting. A decrease in physical performance accompanied all of these alterations. In conclusion, our data indicate that neither methyl-arginine changes nor the Trp/BCAA ratio can explain exercise-induced fatigue after fasting. However, the observed decrease in hArg concentration suggests the limited synthesis of creatine, possibly contributing to reduced physical performance.
运动后血清甲基精氨酸和氨基酸浓度的变化已有充分的文献记载，而运动与禁食联合应用的影响仍存在争议，且尚未得到深入研究。因此，我们假设 ADMA、SDMA 和 L-NMMA 等甲基精氨酸的变化可能是 8 天禁食后运动能力下降的原因。此外，我们提出，人体暴露于超过一周的长时间禁食的情况下，对运动的反应与一夜禁食后明显不同。一组有过禁食经验的 10 名健康男性参与了这项研究。在 8 天禁食前后，进行了逐渐增加强度的直至力竭的运动测试。在运动前和运动后立即采集血样。通过 ID-LC-MS/MS 分析血清样本中的 ADMA、SDMA、L-NMMA、二甲胺和氨基酸。SDMA、L-NMMA 和二甲胺在 8 天禁食后显著下降，而 ADMA 没有变化。BCAA、Phe、丙氨酸和其他一些氨基酸在禁食后增加。与一夜禁食相比，8 天禁食后运动引起的氨基酸变化明显不同。所有这些变化都伴随着体力活动能力的下降。总之，我们的数据表明，甲基精氨酸的变化或 Trp/BCAA 比值都不能解释禁食后运动引起的疲劳。然而，观察到的 hArg 浓度降低表明肌酸的合成有限，可能导致体力活动能力下降。
