无训练年轻女性骑车与跑步的脂肪氧化动力学及最大脂肪氧化研究

Fat Oxidation Kinetics and Maximal Fat Oxidation of Untrained Young Women during Cycling and Running

目的：比较无训练年轻女性骑车与跑步的脂肪氧化动力学、最大脂肪氧化强度（Fatmax）和最大脂肪氧化率（MFO）的差异。方法：12名无训练年轻女性采用递增负荷模式分别完成自行车测试和跑台测试．测定每级负荷运动过程中机体的气体代谢指标．采用每级负荷后30秒气体代谢数据计算脂肪氧化率，通过3阶数多项式拟合曲线确定脂肪氧化动力曲线及Fatmax和MFO。结果：运动强度和运动方式对脂肪氧化率均有影响。随着运动强度增加．脂肪氧化率呈先增加后减少的变化趋势。骑车的脂肪氧化率在50％-60％V02max强度阶段呈现相对较高水平（4．48-4．68mg/min／kg），跑步的脂肪氧化率在50％～65％V02max强度阶段呈现相对较高水平（6．36-6．67mg／min／kg）。相同强度跑步运动脂肪氧化率高于骑车运动．最大脂肪氧化强度和最大脂肪氧化率也高于骑车运动（56．51±2．50％V02max vs 53．18±3．25％V02max，P〈0．05；6．71±1．15mg／min／kg vs 4．74±1．67mg／min／kg，P〈0．001）。骑车和跑步诱导脂肪氧化率达最大的95％以上强度范围分别为44．86。60．60％V02max和48．21～65．41％V02max。结论：相同强度运动，跑步脂肪氧化率高于骑车．且跑步最大脂肪氧化强度和最大脂肪氧化率也高于骑车，提示在对肥胖、糖尿病及与脂肪代谢相关的其他疾病的运动干预中，跑步的干预效果可能优于骑车。

Objective The aim of the study is to compare the fat oxidation kinetics, exercise intensity eliciting maximal fat oxidation（Fatmax） and maximal fat oxidation rate（MFO） of untrained young women during cycling and running. Methods 12 healthy untrained young women performed two incremental exercise tests respectively on a cycle ergometer and a treadmill,and the gas metabolism data in the last 30 seconds of each load were measured to calculate fat oxidation rate,and then a 3rd polynomial fitting curve was used to determine fat oxidation kinetics curve,Fatmax, and MFO. Results As exercise intensity increased, fat oxidation rate tended to increase first and then decrease. The higher levels of fat oxidation rate was seen in cycling at 50%-60% VO2max （4.48-4.68 mg/min/kg）,and in running at 50%-65% VO2max（6.36±6.67 mg/min/kg）. Fat oxidation rates were significantly higher during the running than thecycling at the same intensity,and Fatmax and MFO were significantly higher during running than cycling （56.51±2.50%VO2max vs 53.18±3.25%VO2max,P 〈 0.05 ;6.71±1.15 mg/min/kg vs 4.74±1.67 mg/min/kg,P 〈 0.001）. The intensity,at which fat oxidation more than 95%MFO,were 44.86-60.60%VOEmax for cycling and 48.21%-455.4 1%VO2max for running. Conclusion Fat oxidation rates, Fatmax and MFO were higher during running than cycling at the same intensity,suggesting that running could be better than cycling in the exercise intervention for obesity, diabetes and others associated with fat metabolism disorder.