RESUMO
To determine whether exercise intensity influences acute HDL-C responses, 12 male recreational runners (24.8 +/- 4 yr) who ran 15-30 miles.wk-1 exercised on a motor driven treadmill at 60% (L) and 75% (H) VO2max. A counterbalanced experimental design was utilized and energy expenditure was 800 Kcal. Fasting blood samples were obtained 24 h before exercise (24 PRE), immediately post-(IPE), 1 h post- (1 h PE), 6 h post- (6 h PE), and 24 h post- (24 h PE) exercise and analyzed for HDL-C and HDL2&3-C. In addition, postheparin plasma samples, obtained 24 h PRE, 6 h PE, and 24 h PE were analyzed for lipolytic activity--LPLA and HTGLA. An exercise trial by time interaction was observed for HDL-C (P < 0.01). Post-hoc analysis revealed no change in HDL-C following the L trial. However, an increase in HDL-C was observed 24 h PE (P < 0.01) following the H trial. The increase in HDL-C was attributed to an elevated HDL3-C (P < 0.01), with no change in HDL2-C. Analysis of plasma lipolytic activity revealed an increase in LPLA 24 h PE (P < 0.05) which may be responsible for the postexercise alterations in HDL-C. However, HTGLA decreased 6 h PE (P < 0.01) and 24 h PE (P < 0.05). We conclude that increases in HDL-C levels following endurance activity are influenced, in part, by the exercise intensity.
Assuntos
HDL-Colesterol/sangue , Exercício Físico/fisiologia , Adulto , Análise de Variância , Colesterol/sangue , Fatores de Confusão Epidemiológicos , Teste de Esforço , Humanos , Lipase/sangue , Lipase Lipoproteica/sangue , Masculino , Consumo de Oxigênio , Volume Plasmático , Fatores de Tempo , Triglicerídeos/sangueAssuntos
Consumo de Oxigênio , Modalidades de Fisioterapia , Traumatismos da Medula Espinal/metabolismo , Adulto , Estimulação Elétrica , Metabolismo Energético/fisiologia , Feminino , Humanos , Articulação do Joelho/fisiologia , Masculino , Contração Muscular , Músculos/fisiologia , Traumatismos da Medula Espinal/terapia , Terapia Assistida por ComputadorRESUMO
The effect of blood glucose extraction on the perception of exertion was examined during prolonged arm exercise. Eight male subjects consumed in counter-balanced order a standard daily diet containing either (1) 75 g dihydroxyacetone and 25 g sodium pyruvate (DHAP) or (2) an isocaloric amount of placebo, to manipulate blood glucose extraction. Following each 7-day diet, subjects exercised to exhaustion at 60% of peak arm oxygen consumption. Ratings of perceived exertion (Borg, CR-10 scale) were obtained for the arms (RPE-A), legs (RPE-L), chest (RPE-C) and overall body (RPE-O) every 10 min of exercise. After 60 min of continuous exercise, blood samples were drawn from the radial artery and axillary vein. Ratings of perceived exertion did not differ between trials during the first 50 min of exercise. At the 60-min time point, perceived exertion was lower (P less than 0.01) in the DHAP than placebo trials for the arms (RPE-A: 4.25 vs 5.50) and overall body (RPE-O: 3.25 vs 4.00). These differences persisted throughout exercise. RPE-L and RPE-C did not differ between trials. Whole-arm arterial-venous glucose difference was higher (P less than 0.05) in the DHAP (1.00 mmol.l-1) than placebo (0.36 mmol.l-1) trials, as was fractional extraction of glucose (22.5 vs 9.0%). Respiratory exchange ratio was the same between trials. Triceps muscle glycogen was (1) higher in the DHAP than placebo trial at pre-exercise (P less than 0.05), (2) decreased during exercise and (3) did not differ between trials at exercise termination.(ABSTRACT TRUNCATED AT 250 WORDS)