title: Effect of exercise intensity on fat utilization in males and females.
abstract: This study was conducted to assess fat utilization across different exercise intensities and between males and females. Eleven males and 11 females completed a maximal test and four submaximal trials at 40%, 50%, 60%, and 70% VO(2) peak. The VO(2) peak and ventilatory threshold (VT) were assessed during the maximal test. Caloric expenditure (Cal), carbohydrate (COX), and fat oxidation (FOX) were measured during each submaximal trial. Maximal fat oxidation (Fmax) was determined as the intensity where the highest FOX was observed. There was no main effect of intensity on FOX. FOX was higher in (p < 0.05) in women than in men at 40% VO(2)peak. The Fmax occurred most frequently at 60% VO(2)peak and correlated with VT (r = 0.62) and VO(2) peak (r = 0.64). In conclusion, despite the fact that Fmax is most frequently observed at 60% VO(2) peak, rates of fat oxidation remained statistically similar across intensities from 40% to 70% VO(2)peak. Women oxidized more fat than men at 40% VO(2)peak, but this gender difference did not occur at higher intensities. It appears that exercising within the moderate intensity domain will produce similar rates of fat utilization.
authors.affiliation: Human Performance Laboratory, Department of Health and Exercise Science, The College of New Jersey, Ewing, New Jersey, USA. kang@tcnj.edu
authors.forename: Jie
authors.initials: J
authors.lastname: Kang
authors.forename: Jay R
authors.initials: JR
authors.lastname: Hoffman
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: Ratamess
authors.forename: Avery D
authors.initials: AD
authors.lastname: Faigenbaum
authors.forename: Michael
authors.initials: M
authors.lastname: Falvo
authors.forename: Michael
authors.initials: M
authors.lastname: Wendell
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism*; D000328:Adult; D004734:Energy Metabolism; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D010101:Oxygen Consumption; D005082:Physical Exertion / Q000502:physiology*; D011446:Prospective Studies; D012737:Sex Factors; D016526:Workload