John C. Wirth

No Ergogenic Effects of Ginseng (Panax Ginseng C.A. Meyer) during Graded Maximal Aerobic Exercise

OBJECTIVE To assess the effects of chronic supplementation with two different dosages of Panax ginseng C.A. Meyer on physiologic and psychological responses during graded maximal aerobic exercise. DESIGN Randomized, double-blind, placebo-controlled trial. SUBJECTS Thirty-six healthy men consuming an otherwise supplement-free diet who maintained their usual activity level. INTERVENTION A standardized P ginseng C.A. Meyer concentrate (G115) was added to the normal diet of study participants at a dosage level of either 200 or 400 mg/day, where 100 mg of the preparation is equivalent to 500 mg P gingseng root. MAIN OUTCOME MEASURES Submaximal and maximal aerobic exercise responses before and after an 8-week trial intervention. STATISTICAL ANALYSES PERFORMED Analysis of variance. RESULTS Thirty-one subjects completed the study. Supplementation with ginseng had no effect on the following physiologic and psychological parameters: oxygen consumption (mL/kg per minute), respiratory exchange ratio, minute ventilation (L/min), blood lactic acid concentration (mmol/L), heart rate (beats/min), and perceived exertion (P > .05). CONCLUSIONS Our data in healthy men do not offer support for claims that P ginseng C.A. Meyer is an ergogenic aid to improve submaximal and maximal aerobic exercise performance.

Effects of ginseng on secretory IgA, performance, and recovery from interval exercise

PURPOSE This study examined the efficacy of ginseng to modulate secretory immunoglobulin A (SIgA), exercise performance, and recovery from repeated bouts of strenuous physical exertion. METHODS Using a double-blind, placebo-controlled, randomized design, 38 active healthy adults supplemented their diets with a standardized ginseng concentrate (400 mg.d-1 of G115; equivalent to 2 g of Panax ginseng C.A. Meyer root material) or placebo (lactose) for 8 wk. Before and after the intervention, each subject performed three consecutive 30-s Wingate tests interspersed with 3-min recovery periods under controlled laboratory conditions. SIgA secretion rate (S-SIgA) and the relation of SIgA to total protein were calculated from measures of saliva flow rate (SFR), and absolute SIgA and salivary protein concentrations in timed, whole unstimulated saliva samples collected before and after exercise testing. Peak and mean mechanical power output (W.kg-1) was measured with an infrared-beam optical-sensor array, and exercise recovery heart rate (HRR) was determined electrocardiographically. RESULTS Twenty-seven subjects (12 placebo, 15 ginseng) completed the study. Compared with rest, S-SIgA, SIgA:protein ratio, and SFR were lower after exercise at baseline (P < 0.05). Similarly, both peak and mean mechanical power output declined (P < 0.01) across consecutive Wingate tests. Postintervention minus preintervention change scores for salivary parameters, exercise performance, and HRR were similar between ginseng- and placebo-treated groups (P > 0.05). CONCLUSION These findings do not support the hypothesis that ginseng may affect mucosal immunity as indicated by changes in secretory IgA at rest and after an exercise induced state of homeostatic disturbance. Supplementation with ginseng fails to improve physical performance and heart rate recovery of individuals undergoing repeated bouts of exhausting exercise.

Effects of ginseng supplementation on supramaximal exercise performance and short-term recovery.

The purpose of this study was to examine the effects of long-term ginseng supplementation on short, supramaximal exercise performance and short-term recovery. Using a double-blind protocol, 24 healthy, active women were randomly assigned to a ginseng (n = 12) or placebo (n = 12) treatment group. Each participant added a standardized extract of Panax ginseng C.A. Meyer (400 mg per day of G115) or placebo to their normal diet for 8 weeks (56–60 days). Before and after the trial period, each subject performed an all-out-effort, 30-second leg cycle ergometry test (Wingate protocol) followed by a controlled recovery under constant laboratory conditions. Nineteen subjects completed the study. Analysis of variance using pretest to posttest change scores revealed no significant difference between the ginseng and placebo study groups for the following variables measured: peak anaerobic power output, mean anaerobic power output, rate of fatigue, and immediate postexercise recovery heart rates (p > 0.05). In conclusion, the present data indicate that prolonged supplementation with ginseng (P. ginseng C.A. Meyer) has no ergogenic benefits during and in the recovery from short, supramaximal exercise.

Failure of chronic ginseng supplementation to affect work performance and energy metabolism in healthy adult females

Abstract Ginseng has long been used for various medicinal reasons in East Asia and has recently also become a popular nutritional supplement in Western countries. Although commonly alleged to increase work performance by enhancing the body resistance to stress and fatigue, human experimental research evidence to either support or refute these claims is limited and conflicting. Therefore, this randomized, double-blind, placebo-controlled study served to examine a group of healthy adult females who for eight weeks added 200 mg·day −1 of a concentrated extract of Panax Ginseng C.A. Meyer (n=10) or placebo (n=9) to their otherwise supplement-free normal diet. Before and after the trial intervention, each subject performed a graded maximal cycle ergometry test to exhaustion and completed a standard habitual physical activity questionnaire. It was observed that chronic ginseng supplementation had no effect on maximal work performance (J) and resting, exercise, and recovery oxygen uptake (VO 2 , ml·kg −1 ·min −1 ), respiratory exchange ratio (RER), minute ventilation (VE, L·min −1 ), heart rate (beats·min −1 ), and blood lactic acid (mmol·L −1 ) levels (p>0.05). Habitual physical activity scores of study participants were found to be similar between the placebo and ginseng treatment groups and at the beginning and end of the eight week trial period (p>0.05). The present data in healthy adult females indicate that chronic dietary supplementation with a standardized extract of Panax Ginseng C.A. Meyer does not result in an enhancement of work performance or a change in energy metabolism and improvement of the recovery response from maximal physical work.

Attitudes of Employees for an On-Campus Health Promotion Program at a Large Urban University

This article describes the results of a survey among employees at Wayne State University that were designed to determine the desire for and willingness to participate in a campus wellness program. All 4,300 employees were mailed a questionnaire during the period March-June 1989. Among the 2,401 respondents (56% response rate), 81% felt a wellness program should be offered and 57% indicated an intention to participate. A significantly higherpercentage ofBlacks (77%) and women (62%) stated they would participate as compared to Whites (51%) and men (51%). There was an inverse relationship between desire for the program and income level; those who held commercial health club memberships and resided closerto campus showed higher interest. In the overall sample, lunchtime activities were the most requested. Types of services most requested included health screening (e.g., cholesterol testing and fitness assessment) and exercise classes.

CLUSTER ANALYSIS OF LEVELS OF BODY FATNESS IN CHILDREN

The purpose of this study was to examine, using cluster analysis, the levels of body fatness as defined in the current national programs for children and youth fitness. A total of 1,056 examinees were drawn randomly from the published data of the National Children and Youth Fitness Study II, with 525 boys and 531 girls, ages 6 to 9 years. Their triceps and medial calf skinfold measures were used for the cluster analysis, including both the kth nearest-neighbor and the Wards minimum variance procedures. Although multimodal clusters were found at four age groups according to the kth nearest-neighbor procedure, the Ward procedure and plotting of these clusters did not support their existence. It was concluded that the levels of body fatness reported in the current national children and youth fitness programs were arbitrarily defined.