title: Metabolic, cardiovascular, and perceptual responses to a thermogenic nutritional supplement at rest, during exercise, and recovery in men.
abstract: Twenty-one men (mean ± SD; age = 23.5 ± 2.6 years, BMI = 26.0 ± 2.4 kg-1·m-2) completed this randomized, double-blinded, placebo-controlled, crossover study to examine acute responses to a thermogenic nutritional supplement. Each testing session included: (a) 30 minutes resting, followed by placebo or thermogenic nutritional supplementation, (b) 50 minutes postsupplementation resting, (c) 60 minutes walking, and (d) 50 minutes postexercise recovery. Gas exchange variables and heart rate (HR) were recorded during each phase. Blood pressure was recorded during all phases except exercise. Ratings of perceived exertion (RPE) were recorded only during exercise. There were no significant differences for any of the measures between the supplement and placebo during the initial resting or postsupplementation phases. During exercise, energy expenditure (EE) (placebo = 18.98-19.06 kJ·min-1 and supplement = 19.44-19.82 kJ·min-1) and VO2 (placebo = 11.27-11.35 ml·kg-1·min-1; supplement = 11.64-11.82 ml·kg-1·min-1) were greater for the supplement than placebo. There were no differences in respiratory exchange ratio (RER), HR, or RPE between the supplement and placebo during exercise. Postexercise, only VO2 (placebo = 3.53-3.63 ml·kg-1·min-1; supplement = 3.71-3.84 ml·kg-1·min-1) was greater for the supplement than placebo, but there were no differences in EE, RER, HR, or blood pressure. These findings suggested that the specific blend of ingredients in the thermogenic nutritional supplement, when combined with exercise, increased the metabolic rate with minimal changes in cardiovascular function and no effect on RPE.
authors: 1Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska; and 2College of Dentistry, University of Nebraska Medical Center, Lincoln, Nebraska.
authors: Haley C
authors: HC
authors: Bergstrom
authors: Terry J
authors: TJ
authors: Housh
authors: Daniel A
authors: DA
authors: Traylor
authors: Robert W
authors: RW
authors: Lewis
authors: Kristen C
authors: KC
authors: Cochrane
authors: Nathaniel D M
authors: ND
authors: Jenkins
authors: Richard J
authors: RJ
authors: Schmidt
authors: Glen O
authors: GO
authors: Johnson
authors: Dona J
authors: DJ
authors: Housh
authors: Joel T
authors: JT
authors: Cramer
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D018592:Cross-Over Studies; D019587:Dietary Supplements; D004311:Double-Blind Method; D004734:Energy Metabolism / Q000187:drug effects / Q000502:physiology; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000187:drug effects / Q000502:physiology; D005082:Physical Exertion / Q000187:drug effects / Q000502:physiology; D011659:Pulmonary Gas Exchange / Q000187:drug effects / Q000502:physiology; D012146:Rest / Q000502:physiology*; D022722:Thermogenesis; D016138:Walking / Q000502:physiology*; D055815:Young Adult