Abstract des Autors

The purpose of this study was to examine the effect of preliminary walking on free fatty acid (FFA) responses and calculated substrate utilization during a 40-min treadmill run. Repeated 12-hour post-prandial measures were obtained on six endurance trained subjects (M VO2 max = 69.3 ml/kg) running at approximately 65 of their maximal aerobic power; preceded by rest in the without warm-up (WOW) trial or by a 20-min walk at approximately 27 of their maximal aerobic power in the with warm-up (WW) trial. Significantly different quadratic trends in FFA concentrations were found between trials. The WW trial displayed mean FFA concentrations above resting levels at sampling periods throughout the run. The WOW trial showed a fall in the mean FFA concentrations after the first 10 min of running, a return to approximately resting levels after 20 min, and elevated concentrations at 40 min. The percentage of energy derived from fat metabolism (calculated from steady state respiratory exchange ratios) was significantly higher in the WW trial (p<.05). It was calculated that a mean of 23.1 grams of carbohydrate was spared during exercise by the warm-up procedure. It was concluded that a low energy expenditure warm-up is sufficient to facilitate FFA mobilization and utilization during a subsequent submaximal run. Verf.-Referat