Thermogenic Effect of a High Energy, Pre-exercise Supplement

The thermogenic effect of a high energy supplement was examined in ten healthy and physically active female subjects that underwent two testing sessions administered in a randomized and double-blind fashion. The subjects reported to the Human Performance Laboratory after at least a 3-hour post-absorptive state and were provided either 120 ml of the supplement (SUP), or 120 ml of a placebo (PL). Following ingestion the subjects rested in a semi-recumbent position for 3 hours. The area under the curve analysis revealed no difference in oxygen consumption between SUP and PL for the 3 hours study period. No difference in energy expenditure was seen between SUP (.92±.16 kcal·min) and PL (.89±.17 kcal·min). A signifi cant difference in the utilization of stored fat as an energy source was seen between the groups during the 3 hours study (.42±.18 kcal·min and .24±.10 kcal·min in SUP and PL, respectively). These differences were seen in the fi rst (.35 ±.19 kcal·min and .20±.13 kcal·min in SUP and PL, respectively) and second hour (.46±.21 kcal·min and .24±.11 kcal·min in SUP and PL, respectively), but not in the third hour (.47±.25 kcal·min and .33±.20 kcal·min in SUP and PL, respectively). No differences in heart rate, blood pressure or mood were seen between the groups. The results indicate that although acute ingestion of this supplement does not increase energy expenditure, it does appear to stimulate a signifi cant increase in fat utilization.