Hermann J. Engels

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.

Use of Heart Rate Variability to Estimate LT and VT

The purpose of this study was to determine if changes in heart rate variability during incremental exercise could be used to estimate lactate threshold and ventilatory threshold in healthy adults. Twenty-four adults performed graded maximal cycle ergometry to volitional fatigue. Blood lactate, heart rate, RR interval, and respiratory gas exchange were monitored. Heart rate variability was analyzed using time domain indices (standard deviation and mean successive difference). A marked RR interval deflection point was found in the region of lactate threshold and ventilatory threshold, and was identified as the heart rate variability threshold. Mean differences between heart rate variability threshold, ventilatory threshold, and lactate threshold ranged from 0.06 +/- 0.3 to 0.12 +/- 0.2 L.min (-1). Correlations between the different measures ranged from 0.82 - 0.89. A small but significant difference was found between ventilatory threshold and lactate threshold (p < 0.05). There was not a significant difference between heart rate variability threshold and lactate threshold (p > 0.05), nor between heart rate variability threshold and ventilatory threshold (p > 0.05). The data suggest the heart rate variability threshold coincides with lactate threshold and ventilatory threshold during graded exercise and can be used for the detection of lactate threshold in healthy adults.

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 Low-Impact, Moderate-Intensity Exercise Training with and without Wrist Weights on Functional Capacities and Mood States in Older Adults

This study examined the effects of low-impact, moderate-intensity exercise training with and without wrist weights (0.68 kg·wrist–1) on functional capacities and mood states in older adults (age 68.6 ± 5.6, mean ± SD). Twenty-three senior citizens residing in the community were randomly assigned to wrist weight (WW; n = 12) and no-wrist weight (NW; n = 11) exercise groups while 11 matched subjects served as non-exercise controls (NE). Exercise training was performed for 10 weeks, 3 days/week, for 60 min/session and consisted of low-impact aerobic dance (50–70% of maximal heart rate) combined with exercises to promote muscular fitness, flexibility, and balance. Before and after the intervention, each participant’s aerobic fitness, muscular strength, flexibility, static and dynamic balance, skinfold thickness, and psychological mood states were assessed under standardized testing conditions. Exercise training resulted in significant improvements in peak oxygen uptake, lower extremity muscle strength, and psychological vigor (p < 0.05) but did not affect other fitness components (p > 0.05). There were no differences between the WW and NW exercise groups for any of the same variables studied (p > 0.05). No significant pre- to post-test changes were found for the NE control group (p > 0.05). It is concluded that 10 weeks of low-impact, moderate-intensity exercise training of the type that can be considered well-rounded in nature provides a sufficient stimulus to augment aerobic fitness, beneficially affects leg strength, and increases feelings of vigor in older adults. The present observations indicate that the use of light wrist weights has no beneficial or adverse effects on the measured training outcomes.

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.

Resting energy expenditure and delayed-onset muscle soreness after full-body resistance training with an eccentric concentration

Hackney, KJ, Engels, H-J, and Gretebeck RJ. Resting energy expenditure and delayed-onset muscle soreness after full-body resistance training with an eccentric concentration. J Strength Cond Res 22(5): 1602-1609, 2008-The purpose of this investigation was to determine the effect of an acute bout of high-volume, full-body resistance training with an eccentric concentration on resting energy expenditure (REE) and indicators of delayed-onset muscle soreness (DOMS). Eight resistance trained (RT) and eight untrained (UT) participants (mean: age = 23.5 years; height = 180.76 cm; weight = 87.58 kg; body fat = 19.34%; lean mass = 68.71 kg) were measured on four consecutive mornings for REE and indicators of DOMS: creatine kinase (CK) and rating of perceived muscle soreness (RPMS). Delayed-onset muscle soreness was induced by performing eight exercises, eight sets, and six repetitions using a 1-second concentric and 3-second eccentric muscle action duration. A two-factor repeated-measures analysis of variance revealed that REE was significantly (p < 0.05) elevated at 24, 48, and 72 hours post compared with baseline measures for both UT and RT groups. Ratings of perceived muscle soreness were significantly elevated within groups for UT and RT at 24 and 48 hours post and for UT only at 72 hours post compared with baseline (p < 0.05). Nonparametric analyses revealed that CK was significantly increased at 24 hours post for both UT and RT and at 48 and 72 hours post for UT only compared with baseline (p < 0.05). Resting energy expenditure and indicators of DOMS were higher in UT compared with RT on all measures, but no significant differences were determined. The main finding of this investigation is that full-body resistance training with an eccentric concentration significantly increased REE up to 72 hours postexercise in UT and RT participants.

Ginseng does not Enhance Psychological Well-Being in Healthy, Young Adults: Results of a Double-Blind, Placebo-Controlled, Randomized Clinical Trial

OBJECTIVE Ginseng is a popular, commercially available dietary supplement that is purported to have a number of psychological benefits. The purpose of this study was to examine these claims, with specific reference to ginsengs effects on affect and mood. DESIGN Prospective, double-blind, placebo-controlled, randomized clinical trial. PARTICIPANTS/SETTING Eighty-three adults (40 women, 43 men) participated in this study (mean age = 25.7 year). Participants were recruited from within a university community and at area health clubs. INTERVENTION Participants were randomly assigned to one of three experimental conditions: placebo (lactose), 200 mg ginseng, or 400 mg ginseng. The ginseng preparation used in this study consisted of the Panax ginseng C A Meyer concentrate G115 in capsular format. Each participant was given a 60-day allotment of their respective supplement along with written instructions about the proper intake and storage of the capsules during the 8-week study period. MAIN OUTCOME MEASURES Positive affect, negative affect, and total mood disturbance. Measures were obtained pre- and post-intervention. STATISTICAL ANALYSES PERFORMED Repeated measures multivariate analysis of variance was used. Because there were three dependent variables, and in an effort to minimize the experimentwise-error rate, alpha was adjusted using the Bonferroni technique (i.e., P < .05/3 = P < .016). RESULTS Ginseng supplementation had no effect on positive affect, negative affect, or total mood disturbance (all P > .016). CONCLUSION The present findings do not support claims that chronic ginseng supplementation--at either its clinically recommended level or at twice that level--enhances affect or mood in healthy young adults.

Effect of Caffeine on LT, VT and HRVT

UNLABELLED Caffeine has many diverse physiological effects including central nervous system stimulation. Ventilatory threshold and a recently described heart rate variability threshold both have a relationship with autonomic control that could be altered by caffeine consumption. The purpose of this investigation was to determine the influence of caffeine on lactate, ventilatory, and heart rate variability thresholds during progressive exercise. Using a randomized placebo controlled, double-blind study design, 10 adults performed 2 graded maximal cycle ergometry tests with and without caffeine (5 mg·kg⁻¹). Respiratory gas exchange, blood lactate concentrations, and heart rate variability data were obtained at baseline and throughout exercise. RESULTS At rest, caffeine (p<0.05) increased blood lactate, oxygen consumption, carbon dioxide production, and minute ventilation. For indices of heart rate variability at rest, caffeine increased (p<0.05) the coefficient of variation, while standard deviation, and mean successive difference displayed non-significant increases. During progressive exercise, minute ventilation volumes were higher in caffeine trials but no other parameters were significantly different compared to placebo tests. CONCLUSION These data demonstrate the robustness of the lactate, ventilatory and heart rate variability thresholds when challenged by a physiological dose of caffeine.

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.

Effects of Exercise on S-IGA and URS in Postmenopausal Women

32 postmenopausal women were randomized to a 16-week home-based walking program or control group. Before and after the intervention, each subject completed a graded maximal treadmill test to establish VO(2)max and resting saliva was collected to determine levels of salivary immunoglobulin A. The 16-week walking program resulted in an increase in VO(2)max (+10.4%; p<0.01). Repeated measures ANOVA revealed a marked increase in the resting secretion rate of salivary immunoglobulin A (+37.4%; p<0.05) in the exercise group following training. Independent of study group, both before and after the intervention, the secretion rate of salivary immunoglobulin A ( - 32.3%) and saliva flow rate (- 29.3%) were reduced following acute maximal exercise (p<0.05). Weekly upper respiratory symptomatology logs revealed that the number of incidences of upper respiratory symptoms throughout the intervention period were the same and the duration per incidence (control: 5.3±1.5 days; exercise: 6.3±2.2 days) were similar between study groups. These findings in postmenopausal women support that the secretion rate of salivary immunoglobulin A and saliva flow rate are reduced immediately following maximal exercise. Moreover, a 16-week moderate intense walking program can increase the secretion of salivary immunoglobulin A without affecting upper respiratory symptomatology.