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.

Bench/step training with and without extremity loading. Effects on muscular fitness, body composition profile, and psychological affect.

BACKGROUND: To study the effect of bench/step group exercise with and without extremity loading on muscular fitness, body composition, and psychological affect. EXPERIMENTAL DESIGN: a prospective training study. SETTING: general community fitness center. PARTICIPANTS: 44 healthy adult females (age: 21-51 yrs). INTERVENTIONS: 12 weeks of bench/ step exercise (3 sessions/week, 50 min/session, 60-90% HRmax). Subjects were randomly assigned to groups that trained with (WT, n=16) and without (NWT, n=16) 0.68 kg/ankle and 1.36 kg/hand weights while 12 subjects served as non-training controls (NTC). MEASURES: Pre- and postintervention muscular strength and endurance for knee and elbow flexion and extension, and for shoulder abduction and adduction were examined by isokinetic dynamometry. Body composition was assessed with hydrostatic weighing and psychological affect by questionnaire. RESULTS: Thirty-two subjects completed the study. ANOVA revealed that pre- to postintervention changes for body fat (2.6%), fat-free weight (+0.7 kg), fat weight (-1.9 kg), and knee flexion peak torque were significantly different in the bench/step exercise trained (WT+NWT) compared to the NTC study group. Specific comparisons of muscle strength and endurance change scores of WT+NWT relative to NTC, and of WT relative to NWT revealed no other significant differences between groups. Positive and negative affective states were similar among study groups before and after the intervention. CONCLUSIONS: Participation in bench/step group exercise improved body composition but was of limited or no value as a modality to change muscular fitness and psychological affect in healthy adult females. The use of ankle and hand weights failed to enhance training adaptations.

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 Ward's 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.

Vitamin B6 status and static muscle function. 2 case reports.

2 young adult females, identified as vitamin B6 deficient based on xanthurenic acid excretion levels following a loading dose of tryptophan, were tested twice during each of 3 menstrual cycles for static muscle strength and endurance of the handgrip muscles. During each of the last 2 cycles either a 25-mg dose of pyridoxine hydrochloride or a placebo were administered daily in the double-blind fashion. Measurement of 24-hour xanthurenic acid and 4-pyridoxic acid excretion levels indicated correction of the biochemical indicators of vitamin B6 deficiency. Results of the tests of static muscle strength and endurance indicated no substantial improvement following vitamin B6 supplementation.

Metabolic and hemodynamic responses to walking with shoulder-worn exercise weights: a brief report.

This study examined the acute physiological responses to steady-rate walking with additional weight carried at shoulder level. Sixteen healthy subjects completed two treadmill walking bouts with and without a 4.54-kg shoulder-worn load carriage system in place. Addition of the external shoulder weights resulted in small increases in level walking oxygen uptake (+0.44 ml.kg-1.min-1; +0.03 L.min-1) and minute ventilation volumes (+0.81 L.min-1) (p < 0.05). RER values, heart rate (+3 beats.min-1), and blood pressure responses [systolic blood pressure (SBP) + 4.5 mm Hg, diastolic blood pressure (DBP) + 1.3 mm Hg] were not significantly changed (p > 0.05). These findings indicate that the efficacy of shoulder-worn exercise weights to augment the physiological demand of walking exercise is marginal at best.

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.

The effect of physical training on the serum iron levels of college-age women.

Physical training in women has been found to be associated with a significant decrease in serum iron levels suggesting a state of deteriorating iron stores. To further study this phenomenon, seventeen women, aged 19 to 23 years, volunteered to participate in a 10-week physical training program to study the effect of training on serum iron levels. The training consisted of three 20-25 minute exercise bouts per week on a bicycle ergometer with individual workloads equivalent to approximately 70% of each subject's maximum aerobic capacity. Additionally, eight women, aged 19 to 28, volunteered to act as a control group. Assessments of hemoglobin (Hb), hematocrit (Hct), serum iron (SeFe), and maximum oxygen uptake (Vo2 max) were made on both groups prior to and at the conclusion of the training period. Upon completion of training, Vo2 max (ml/kg/min) increased by eleven percent (p less than .05) whereas Gb and Hct showed no significant changes for the trainign group with respect to the control group. Se Fe levels (microgram/100ml) in the training group did not differ significantly from those of the control group in both pre-training (128.8 +/- 7.6 vs 103.7 +/- 13.7, X +/- SE) and post-training (126.6 +/- 7.9 vs. 120.9 +/- 16.3, X +/- SE) conditions. Neither day of menstrual cycle nor use of oral contraceptives nor use of iron supplements was found to have any systematic effect on SeFe levels. The results suggest that short term physical training in college-age women does not significantly lower SeFe levels.

Nutritional Practices of Coaches in the Big Ten.

Many coaches in Big Ten schools still burden their athletes with a protein-rich precompetition meal. This survey indicates that coaches need-and want-more and better information about nutrition.

Influence of caffeine on metabolic and cardiovascular functions during sustained light intensity cycling and at rest.

This study assessed the influence of caffeine on metabolic and cardiovascular functions during sustained, light intensity cycling and at rest. Eight healthy, recreationally active adults participated in four randomly assigned, double-blind experimental trials of 60 min upright seated cycle exercise (30% VO2 max) or equivalent rest with caffeine (5 mg.kg-1) or placebo consumed 60 min prior to data collection. Gas exchange was measured by open-circuit spirometry indirect calorimetry. Global blood flow was evaluated by thoracic impedance cardiography and arterial blood pressure by auscultation. A repeated measures ANOVA indicated that pretrial caffeine increased oxygen uptake and energy expenditure rate (p < 0.05) but did not change respiratory exchange ratio. Systolic, diastolic, and mean arterial blood pressure were elevated following caffeine intake (p < 0.05). Cardiac output, heart rate, stroke volume, and systemic vascular resistance were not significantly different between caffeine and placebo sessions. For each of the metabolic and hemodynamic variables examined, the effects of caffeine were similar during constant-load, light intensity cycling and at rest. These data illustrate that caffeine's mild thermogenic influence can be mediated without a major shift in substrate oxidation mixture. Caffeine at this dosage level alters cardiovascular dynamics by augmenting arterial blood pressure.