THE EFFECT OF ELEUTHEROCOCCUS SENTICOSUS (SIBERIAN GINSENG) ON SUBSTRATE UTILIZATION AND PERFORMANCE DURING PROLONGED CYCLING

444 It has been suggested that Eleutherococcus senticosus (ES), also known as Siberian ginseng or ciwuija, has the ability to increase fat utilization in man. This implies a sparing effect of muscle glycogen stores, and possible enhancement in performance during prolonged work. Recent well-designed studies have shown no effect on short duration work; however, there are no studies investigating long duration work. Therefore, it was the purpose of this study to examine the physiological responses to supplementation of ES on endurance cyclists. Using a randomized, double-blind crossover design, 10 highly-trained men (28 ±1 yr, VO2max 56.9 ±1.8 ml·kg−1·min−1) cycled for 120 min at ∼60% VO2max followed by a simulated 10-km time trial. Diet was controlled and ES (1200-mg·day−1) or a placebo (P) were administered for seven days prior to each of the two trials. Oxygen consumption, respiratory exchange ratio, and heart rate were recorded every 30-min and rating of perceived exertion, plasma lactate, and plasma glucose were recorded every 20 min during the 120 min of steady state. 10-km performance time was recorded for the time trial. There were no significant differences (P>0.05) between the ES and P groups at any steady-state measurement point or during the cycling time trial (ES, 18.41 ±0.49; P, 18.21 ±0.57 min). These results suggest that ES supplementation does not alter steady-state substrate utilization or 10-km cycling performance time. Supplement provided by PacificHealth Laboratories, Inc.