摘要
Background:Decaffeinated green tea extract(dGTE)can increase fat oxidation during leg exercise,but dGTE is unsuitable for many people(e.g.,those with injuries/disabilities),and its effects on arm exercise and women are unknown.Methods:Eight adults(23-37 years old,4 women)performed an incremental arm cycle test to measure peak oxygen uptake(VO_(2_(peak))),followed by four 1-h trials at 50%VO_(2_(peak).Subjects were randomly assigned to 650 mg of dGTE or placebo(PLA)for 4 weeks followed by a 4-week washout and crossover trial.Blood samples were obtained pre-exercise and post-exercise for glycerol and free fatty acid analysis.Respiratory gases were collected continuously.Results:VO_(2) showed no differences across trials((0.83-0.89)±(0.19-0.25)L/min,p=0.460),neither did energy expenditure((264-266)±(59-77)kcal,p=0.420)nor fat oxidation(dGTE=0.11 to 0.12 g/min vs.PLA=0.10 to 0.09 g/min,p=0.220).Fat oxidation as percentage of energy expenditure was not different for dGTE vs.PLA(23%±12%to 25%±11%vs.23%±10%to 21%±9%,p=0.532).Glycerol concentration increased post-exercise in all trials,independent of treatments(pre=(3.4-5.1)±(0.6-2.6)mg/dL vs.post=(7.9-9.8)±(2.6-3.7)mg/dL,p=0.867,η^(2)=0.005 for interaction),as did free fatty acid((3.5-4.8)±(1.4-2.2)mg/dL vs.(7.2-9.1)±(2.6-4.5)mg/dL,p=0.981,η^(2)=0.000).Conclusion:Chronic dGTE supplementation had no effect on lipolysis and fat oxidation during arm cycle exercise in men and women.
基金
University Grants Program 242545,San Diego State University。
作者简介
Corresponding author:Jochen Kressler.E-mail address:jkressler@mail.sdsu.edu。
