This study investigated within-subject variability in the circulating metabolome under controlled conditions, and whether divergent exercise training backgrounds were associated with alterations in the circulating metabolome assessed in resting samples. Thirty-seven men comprising of endurance athletes (END; body mass, 71.0 ± 6.8 kg; fat-free mass index, 16.9 ± 1.1 kg/m²), strength athletes (STR; 94.5 ± 8.8 kg; 23.0 ± 1.8 kg/m²), and recreationally active controls (CON; 77.6 ± 7.7 kg; 18.1 ± 1.0 kg/m²) provided blood samples after an overnight fast on two separate occasions controlled for time of day of sampling, recent dietary intake, time since last meal, and time since last exercise training session. A targeted profile of metabolites, performed using liquid chromatography and mass spectrometry on plasma samples, identified 166 individual metabolites and metabolite features, which were analyzed with intraclass correlation coefficients, a multilevel principal component analysis, and univariate t tests adjusted for multiple comparisons. The median intraclass correlation coefficient was .49, with 46 metabolites displaying good reliability and 31 metabolites displaying excellent reliability. No difference in the abundance of any individual metabolite was identified within groups when compared between visits, but a combined total of 44 metabolites were significantly different (false discovery rate <0.05) between groups (END vs. CON, 42 metabolites; STR vs. CON, 10 metabolites; and END vs. STR, five metabolites). Under similar measurement conditions, the reliability of resting plasma metabolite concentrations varies largely at the level of individual metabolites with ∼48% of metabolites displaying good-to-excellent reliability. However, a history of exercise training was associated with alterations in the abundance of ∼28% of metabolites in the targeted profile employed in this study.

本研究调查了受控条件下循环代谢组的受试者内变异性，以及不同的运动训练背景是否与静息样本中评估的循环代谢组的改变相关。37 名男性，包括耐力运动员（END；体重，71.0 ± 6.8 kg；去脂体重指数，16.9 ± 1.1 kg/m 2 ）、力量运动员（STR；94.5 ± 8.8 kg；23.0 ± 1.8 kg ^/ m ² ), 和娱乐活动控制 (CON; 77.6 ± 7.7 kg; 18.1 ± 1.0 kg/m ²) 在两个不同的场合提供了隔夜禁食后的血液样本，这些样本控制了一天中的采样时间、最近的饮食摄入量、自上次进餐以来的时间以及自上次运动训练以来的时间。使用液相色谱法和质谱法对血浆样品进行代谢物的靶向分析，确定了 166 种单独的代谢物和代谢物特征，并通过组内相关系数、多级主成分分析和针对多重比较调整的单变量 t 检验对其进行了分析。组内相关系数中位数为 0.49，其中 46 种代谢物显示出良好的可靠性，31 种代谢物显示出极佳的可​​靠性可靠性。在访问之间进行比较时，组内没有发现任何单个代谢物的丰度差异，但总共有 44 种代谢物在组间有显着差异（错误发现率 <0.05）（END 与 CON，42 种代谢物；STR 与 CON） ，10 种代谢物；END 与 STR，5 种代谢物）。在类似的测量条件下，静息血浆代谢物浓度的可靠性在单个代谢物水平上差异很大，约 48% 的代谢物显示出良好到极好的可靠性。然而，运动训练的历史与本研究中使用的目标概况中约 28% 的代谢物丰度的改变有关。