Lipid oxidation in fit young adults during postexercise recovery

To evaluate the hypothesis that lipid oxidation predominates in postexercise recovery, we examined healthy men ( n = 6; age = 21.2 ± 0.6 yr) and women ( n = 6; age = 22.8 ± 2.1 yr) during and after two exercise tasks [89 min at 45% and 60 min at 65% of peak rate of oxygen consumption (V̇o2 peak)] as well as a time-matched resting control trial (Con). Exercise bouts were matched for energy expenditure. Respiratory exchange ratios (RER) during exercise at 65% V̇o2 peak for both men and women (0.95 ± 0.01 and 0.93 ± 0.02) were significantly higher than 45% V̇o2 peak (0.89 ± 0.01 and 0.86 ± 0.02) and Con trials (0.86 ± 0.01 and 0.86 ± 0.02, respectively). During recovery, for men RER values were 0.78 ± 0.01 and 0.76 ± 0.01 after 45% and 65% exercise, respectively. For women, values were 0.79 ± 0.01 and 0.78 ± 0.01. These were significantly lower than during both the preexercise resting period and the corresponding no-exercise Con period (0.82 ± 0.01 and 0.83 ± 0.01, mean RER for men and women, respectively). Hence, the contribution of lipid oxidation to energy supply increased significantly during recovery compared with preexercise levels, and it was greater after exercise than during the time-matched, no-exercise Con period. It is concluded that, although carbohydrate is the major fuel source during moderate- to high-intensity exercise, 1) there is substantial postexercise lipid oxidation; and 2) lipid oxidation is the same during postexercise recovery whether the relative power output is 45% or 65% of V̇o2 peak when energy expenditure of exercise is matched.

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An Underfeeding Study in Healthy Men and Women Provides Further Evidence of Impaired Regulation of Energy Expenditure in Old Age

Journal of Nutrition ◽

10.1093/jn/131.6.1833 ◽

2001 ◽

Vol 131 (6) ◽

pp. 1833-1838 ◽

Cited By ~ 31

Author(s):

Sai Krupa Das ◽

Julio C. Moriguti ◽

Megan A. McCrory ◽

Edward Saltzman ◽

Christopher Mosunic ◽

...

Keyword(s):

Energy Expenditure ◽

Old Age ◽

Men And Women ◽

Healthy Men

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Sex Disparities in Thermoregulatory and Metabolic Responses to Mild Cold Exposure Largely Explained by Differences in Body Mass and Body Surface Area

Journal of the Endocrine Society ◽

10.1210/jendso/bvab048.665 ◽

2021 ◽

Vol 5 (Supplement_1) ◽

pp. A326-A326

Author(s):

Yoanna M Ivanova ◽

Tracy Swibas ◽

François Haman ◽

Kerry L Hildreth ◽

Yubin Miao ◽

...

Keyword(s):

Energy Expenditure ◽

Glucose Uptake ◽

Skin Temperature ◽

Body Mass ◽

Body Surface ◽

Cold Exposure ◽

Metabolic Responses ◽

Mean Skin Temperature ◽

Men And Women ◽

Healthy Men

Abstract Sex-related differences in thermoregulatory responses to cold exposure, such as differences in metabolic heat production and fuel selection, are often attributed to differences in morphology and body composition. Whether these differences persist in response to cold when comparing lean, healthy men and women with equivalent total body mass (BM, heat producing capacity) and body surface areas (BSA, heat loss capacity) remains unknown. In this study, we aimed to compare thermoregulatory and metabolic responses to cold exposure in both men and women, before and after matching for BM (± 0.6 kg) and BSA (± 0.01 m2). Data included in this study were derived from four previously published studies and an additional 13 men and 23 women who recently completed an identical 3h mild cold exposure protocol. Included in the analyses were 45 healthy men and 23 healthy women [27 years (95% CI: 25 to 28) in men vs. 34 years (95% CI: 30 to 38) in women, P = 0.0003], including 7 men and women of the same age [28 years (95% CI: 22 to 34) vs. 29 years (95% CI: 22 to 37), P = 0.78] matched for BM and BSA. Using a combination of indirect calorimetry, electromyography and positron emission tomography with 11C-acetate and 18F-fluorodeoxyglucose, we quantified mean skin temperature, whole-body energy expenditure (EE), shivering intensity, brown adipose tissue (BAT) oxidative metabolism and glucose uptake. The cold-induced decrease in mean skin temperature was greater in women than men [-6.4°C (95% CI: -6.7 to -6.0) vs. -5.4°C (95% CI: -5.8 to -5.1), P = 0.0004], whereas EE was higher in men compared to women both during room temperature and cold exposure, with the cold-induced increase in EE being slightly greater in men than women [3.8 kJ·min-1 (95% CI: 3.2 to 4.5) vs. 2.8 kJ·min-1 (95% CI: 2.0 to 3.7), P = 0.07]. In contrast, shivering intensity (%MVC) was higher in women compared to men [3.0 %MVC (95% CI: 2.1 to 3.8) vs.1.8 %MVC (95% CI: 1.5 to 2.2), P = 0.0069]. Cold exposure also increased BAT oxidative index to a similar magnitude in men and women, increasing ~4-fold in men and ~3-fold in women (effect of sex, P = 0.2067). Both fractional glucose uptake [0.022 min-1 (95%CI: 0.017 to 0.027) in men and 0.021 min-1 (95%CI: 0.013 to 0.030) in women, P = 0.02] and net glucose uptake in BAT [92 nmol.g-1.min-1 (95%CI: 69 to 115) in men and 91 nmol.g-1.min-1 (95%CI: 53 to 129) in women] were not different between the sexes without or with matching for BM and BSA. The sex differences in mean skin temperature, energy expenditure and shivering intensity were all lost once participants were matched for BM and BSA. The present results suggest that much of the sexual dimorphism in thermoregulatory and metabolic responses to mild cold exposure can be explained by differences in BM and BSA.

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To Study the Effect of Aprocitentan on the Electrical Activity of the Heart in Healthy Men and Women

Case Medical Research ◽

10.31525/ct1-nct04281342 ◽

2020 ◽

Author(s):

Keyword(s):

Electrical Activity ◽

Men And Women ◽

Healthy Men

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Faculty Opinions recommendation of Impact of chronic dietary red meat, white meat, or non-meat protein on trimethylamine N-oxide metabolism and renal excretion in healthy men and women.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.734611844.793560234 ◽

2019 ◽

Author(s):

J David Spence

Keyword(s):

Renal Excretion ◽

Red Meat ◽

White Meat ◽

Men And Women ◽

Healthy Men ◽

Meat Protein

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Dietary Fat Chain Length, Saturation, and PUFA Source Acutely Affect Diet-Induced Thermogenesis but Not Satiety in Adults in a Randomized, Crossover Trial

Nutrients ◽

10.3390/nu13082615 ◽

2021 ◽

Vol 13 (8) ◽

pp. 2615

Author(s):

Bret M. Rust ◽

Susan K. Raatz ◽

Shanon L. Casperson ◽

Sara E. Duke ◽

Matthew J. Picklo

Keyword(s):

Energy Expenditure ◽

Dietary Fatty Acids ◽

Degree Of Saturation ◽

Postprandial Period ◽

Men And Women ◽

Adult Men ◽

Randomized Crossover Trial ◽

Structural Differences ◽

Diet Induced Thermogenesis ◽

Postprandial Energy Expenditure

Structural differences in dietary fatty acids modify their rate of oxidation and effect on satiety, endpoints that may influence the development of obesity. This study tests the hypothesis that meals containing fat sources with elevated unsaturated fats will result in greater postprandial energy expenditure, fat oxidation, and satiety than meals containing fats with greater saturation. In a randomized, 5-way crossover design, healthy men and women (n = 23; age: 25.7 ± 6.6 years; BMI: 27.7 ± 3.8 kg/m2) consumed liquid meals containing 30 g of fat from heavy cream (HC), olive oil (OO), sunflower oil (SFO), flaxseed oil (FSO), and fish oil (FO). Energy expenditure and diet-induced thermogenesis (DIT) were determined by metabolic rate over a 240 min postprandial period. Serum concentrations of ghrelin, glucose, insulin, and triacylglycerol (TAG) were assessed. DIT induced by SFO was 5% lower than HC and FO (p = 0.04). Energy expenditure and substrate oxidation did not differ between fat sources. Postprandial TAG concentrations were significantly affected by fat source (p = 0.0001). Varying fat sources by the degree of saturation and PUFA type modified DIT but not satiety responses in normal to obese adult men and women.

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