De Souza Silveira Raul, Carlsohn Anja, Langen Georg, Mayer Frank, Scharhag-Rosenberger Friederike
University Outpatient Clinic, Center of Sports Medicine, Potsdam University, Potsdam, Germany ; Swiss Federal Institute of Sport Magglingen, Magglingen, Switzerland.
University Outpatient Clinic, Center of Sports Medicine, Potsdam University, Potsdam, Germany ; Department of Health Sciences, University of Education Schwaebisch Gmuend, Schwaebisch Gmuend, Germany.
J Int Soc Sports Nutr. 2016 Jan 25;13:4. doi: 10.1186/s12970-016-0115-1. eCollection 2016.
Exercising at intensities where fat oxidation rates are high has been shown to induce metabolic benefits in recreational and health-oriented sportsmen. The exercise intensity (Fatpeak) eliciting peak fat oxidation rates is therefore of particular interest when aiming to prescribe exercise for the purpose of fat oxidation and related metabolic effects. Although running and walking are feasible and popular among the target population, no reliable protocols are available to assess Fatpeak as well as its actual velocity (VPFO) during treadmill ergometry. Our purpose was therefore, to assess the reliability and day-to-day variability of VPFO and Fatpeak during treadmill ergometry running.
Sixteen recreational athletes (f = 7, m = 9; 25 ± 3 y; 1.76 ± 0.09 m; 68.3 ± 13.7 kg; 23.1 ± 2.9 kg/m(2)) performed 2 different running protocols on 3 different days with standardized nutrition the day before testing. At day 1, peak oxygen uptake (VO2peak) and the velocities at the aerobic threshold (VLT) and respiratory exchange ratio (RER) of 1.00 (VRER) were assessed. At days 2 and 3, subjects ran an identical submaximal incremental test (Fat-peak test) composed of a 10 min warm-up (70 % VLT) followed by 5 stages of 6 min with equal increments (stage 1 = VLT, stage 5 = VRER). Breath-by-breath gas exchange data was measured continuously and used to determine fat oxidation rates. A third order polynomial function was used to identify VPFO and subsequently Fatpeak. The reproducibility and variability of variables was verified with an intraclass correlation coefficient (ICC), Pearson's correlation coefficient, coefficient of variation (CV) and the mean differences (bias) ± 95 % limits of agreement (LoA).
ICC, Pearson's correlation and CV for VPFO and Fatpeak were 0.98, 0.97, 5.0 %; and 0.90, 0.81, 7.0 %, respectively. Bias ± 95 % LoA was -0.3 ± 0.9 km/h for VPFO and -2 ± 8 % of VO2peak for Fatpeak.
In summary, relative and absolute reliability indicators for VPFO and Fatpeak were found to be excellent. The observed LoA may now serve as a basis for future training prescriptions, although fat oxidation rates at prolonged exercise bouts at this intensity still need to be investigated.
已有研究表明，在脂肪氧化率较高的强度下进行锻炼，对休闲型和以健康为导向的运动员具有代谢益处。因此，当旨在为脂肪氧化及相关代谢效应制定运动处方时，引发最高脂肪氧化率的运动强度（脂肪峰值）就格外令人关注。尽管跑步和步行在目标人群中可行且受欢迎，但在跑步机测功时，尚无可靠的方案来评估脂肪峰值及其实际速度（VPFO）。因此，我们的目的是评估跑步机测功跑步过程中VPFO和脂肪峰值的可靠性及每日变异性。
16名休闲运动员（女性7名，男性9名；年龄25±3岁；身高1.76±0.09米；体重68.3±13.7千克；身体质量指数23.1±2.9千克/米²）在测试前一天采用标准化饮食，于3个不同日期进行2种不同的跑步方案。在第1天，评估峰值摄氧量（VO2peak）、有氧阈速度（VLT）和呼吸交换率为1.00时的速度（VRER）。在第2天和第3天，受试者进行相同的次最大递增测试（脂肪峰值测试），包括10分钟热身（70%VLT），随后是5个阶段，每个阶段6分钟，递增幅度相同（第1阶段=VLT，第5阶段=VRER）。连续测量逐次呼吸气体交换数据，并用于确定脂肪氧化率。使用三阶多项式函数来确定VPFO，进而确定脂肪峰值。通过组内相关系数（ICC）、皮尔逊相关系数、变异系数（CV）以及平均差异（偏差）±95%一致性界限（LoA）来验证变量的可重复性和变异性。
VPFO和脂肪峰值的ICC、皮尔逊相关系数和CV分别为0.98、0.97、5.0%；以及0.90、0.81、7.0%。VPFO的偏差±95%LoA为-0.3±0.9千米/小时，脂肪峰值的偏差±95%LoA为-2±8%VO2peak。
总之，发现VPFO和脂肪峰值的相对和绝对可靠性指标都非常出色。尽管在此强度下长时间运动时的脂肪氧化率仍需研究，但观察到的一致性界限现在可为未来的训练处方提供依据。
Zotero 插件