Resting Metabolic Rate after Endurance Exercise Training

• Autores: Man-Gyoon Lee, Darlene A. Sedlock, Michael G. Flynn, Gary H. Kamimori
• Localización: Medicine & Science in Sports & exercise: Official Journal of the American College of Sports Medicine, ISSN 0195-9131, Vol. 41, Nº. 7, 2009, págs. 1444-1451
• Idioma: inglés
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• Dialnet Métricas: 2 Citas
• Resumen

  • Purpose: 1) To examine the effect of a 12-wk endurance exercise training program on RMR and 2) to provide insight into the mechanisms responsible for alterations in RMR that may occur after exercise training.

    Methods: Male participants (19-32 yr) in an exercise group (EX; n = 9) performed jogging and/or running 3-4 d[middle dot]wk-1, 25-40 min per session, at 60%-80% V[spacing dot above]O2max, whereas subjects in a control group (CON; n = 10) maintained their normal activity patterns. Body composition, V[spacing dot above]O2max, RMR, epinephrine, norepinephrine, total thyroxine, free thyroxine, insulin, free fatty acids, and glucose were measured before and after the intervention.

    Results: Training resulted in a significant increase in V[spacing dot above]O2max in EX (46.2 +/- 1.2 to 51.0 +/- 1.3 mL[middle dot]kg-1[middle dot]min-1, P < 0.001). Absolute and relative values for RMR did not significantly change in EX after training. Mean values for epinephrine, norepinephrine, total thyroxine, insulin, and glucose did not significantly change in either group; however, free thyroxine decreased significantly after training in EX (P = 0.04). Training also resulted in a significant increase in free fatty acid concentration in EX (0.37 +/- 0.03 to 0.48 +/- 0.04 mmol[middle dot]L-1, P < 0.001). RMR in CON decreased significantly when expressed as an absolute value (P < 0.01) and relative to body weight (P < 0.01), fat-free mass (P < 0.01), and fat mass (P = 0.04).

    Conclusions: The mechanism for the decrease in CON is unknown, but it may be related to seasonal variations in RMR. Training may have prevented a similar decline in RMR in EX and may be related to a training-induced increase in fat oxidation.