Publications by authors named "Isabelle Harant"

Article Synopsis
  • * Results showed both age groups experienced similar improvements in cardiometabolic health and insulin sensitivity, but older men had a significant loss of muscle mass, highlighting a potential risk.
  • * The findings emphasize the importance of addressing muscle preservation in older adults during weight loss interventions, amidst rising obesity rates in an aging global population.
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Exercise is a powerful and effective preventive measure against chronic diseases by increasing energy expenditure and substrate mobilization. Long-duration acute exercise favors lipid mobilization from adipose tissue, i.e.

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We hypothesized that skeletal muscle contraction produces a cellular stress signal, triggering adipose tissue lipolysis to sustain fuel availability during exercise. The present study aimed at identifying exercise-regulated myokines, also known as exerkines, able to promote lipolysis. Human primary myotubes from lean healthy volunteers were submitted to electrical pulse stimulation (EPS) to mimic either acute intense or chronic moderate exercise.

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Article Synopsis
  • The study investigated how substrate availability affects fuel selection during exercise in endurance-trained cyclists, comparing performance in rested and fatigued conditions.
  • Eight male cyclists completed a 90-minute exercise session while measuring lipid oxidation and lipolysis after ingesting sucrose.
  • Results indicated that endurance exercise increases fat oxidation and influences fuel selection, emphasizing the importance of lipolysis and free fatty acid availability for effective fat utilization during physical activity.
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Cardiac natriuretic peptides (NP) are major activators of human fat cell lipolysis and have recently been shown to control brown fat thermogenesis. Here, we investigated the physiological role of NP on the oxidative metabolism of human skeletal muscle. NP receptor type A (NPRA) gene expression was positively correlated to mRNA levels of PPARγ coactivator-1α (PGC1A) and several oxidative phosphorylation (OXPHOS) genes in human skeletal muscle.

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Fat oxidation (FO) is optimized during low- to moderate-intensity exercise in lean and obese subjects, whereas high-intensity exercise induces preferential FO during the recovery period. After food intake during the postexercise period, it is unknown if FO differs according to the intensity exercise in overweight subjects. Fat oxidation was thus evaluated in overweight men after low- and high-intensity exercise during the recovery period before and after food intake as well as during a control session.

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Involvement of sympathetic nervous system and natriuretic peptides in the control of exercise-induced lipid mobilization was compared in overweight and lean men. Lipid mobilization was determined using local microdialysis during exercise. Subjects performed 35-min exercise bouts at 60% of their maximal oxygen consumption under placebo or after oral tertatolol [a beta-adrenergic receptor (AR) antagonist].

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Objective: Our objective was to compare the effect of different exercise intensities on lipid oxidation in overweight men and women.

Research Methods And Procedures: Nine young, healthy, overweight men and women were studied (age, 31.4 +/- 2.

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Objective: To explore sex differences in the regulation of lipolysis during exercise, the lipid-mobilizing mechanisms in the subcutaneous adipose tissue (SCAT) of overweight men and women were studied using microdialysis.

Research Methods And Procedures: Subjects matched for age, BMI, and physical fitness performed two 30-minute exercise bouts in a randomized fashion: the first test at 30% and 50% of their individual maximal oxygen uptake (Vo(2max)) and the second test at 30% and 70% of their Vo(2max).

Results: In both groups, an exercise-dependent increment in extracellular glycerol concentration (EGC) was observed.

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Head-down bed rest (HDBR) increases plasma levels of atrial natriuretic peptide (ANP) and decreases norepinephrine levels. We previously demonstrated that ANP promotes lipid mobilization and utilization, an effect independent of sympathetic nervous system activation, when infused into lean healthy men at pharmacological doses. The purpose of the present study was to demonstrate that a physiological increase in ANP contributes to lipid mobilization and oxidation in healthy young men.

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Purpose: This study was designed to evaluate whether a 4-month endurance training program could improve ANP- as well as isoproterenol-mediated (beta-adrenergic receptor agonist) in situ lipolysis and adipose tissue blood flow (ATBF) in the subcutaneous adipose tissue (SCAT) of untrained overweight subjects.

Methods: Ten overweight men aged 26.0 +/- 1.

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Objective: The aim of this study was to determine how training modifies metabolic responses and lipid oxidation in overweight young male subjects.

Research Methods And Procedures: Eleven overweight subjects were selected for a 4-month endurance training program. Before and after the training period, they cycled for 60 minutes at 50% of their VO(2)max after an overnight fast or 3 hours after eating a standardized meal.

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