Effects of Wild Ginseng Extract on Exercise Performance, Cognitive Function, and Fatigue Recovery Using College Students: a Randomized Cross-Over, Placebo-Controlled, and Double-Blind Study
Effects of Wild Ginseng Extract on Exercise Performance, Cognitive Function, and Fatigue Recovery Using College Students: a Randomized Cross-Over, Placebo-Controlled, and Double-Blind Study
The goal of this clinical trial was to learn if Wild Ginseng extract (WG) influences exercise performance, cognitive function, and fatigue recovery from the exercise.
The main questions to answer were:
The investigators will compare WG to a Placebo (a look-alike substance that contains no substance) to see if WG works.
Participants will:
Dietary supplements are used by athletes worldwide. In the United States, the Dietary Supplement Health Education Act has defined dietary supplements as something added to the diet, mainly vitamins, minerals, protein, herbs or botanicals, and metabolites/constituents/extracts, or a combination of any of these ingredients. In the realm of sports performance enhancement, the quest for safe and effective ergogenic aids continues to evolve. With the evolving landscape of supplementation, a significant portion of the Americans tends to favor very specific supplements.
Among the plethora of natural substances garnering attention, wild ginseng extract emerges as a compelling candidate. Ginseng is widely used for its promising healing and restorative properties as well as for its possible tonic effect in traditional medicine and has recently become a popular supplement in Western Countries. There are a multitude of variations among ginseng: among those, Korean ginseng is most notable for its efficacy. To date there have been numerous studies utilizing Korean ginseng attempting to establish an increase in either sports performance, cognitive function, or fatigue recovery. The use of ginseng thus far has not proved much success in the realm of performance enhancement. Conversely, notable achievements have been observed in the realms of cognitive enhancement and fatigue mitigation. The wild ginseng extract has exhibited promising results in ameliorating psychomotor performance and mitigating the effects of chronic fatigue associated with various pathological conditions.
Some issues arise from previous studies of ginseng use as an ergonomic aid. First are the inadequate sample sizes that are being utilized. Secondly are the varying dosages that are being used throughout the study. The issues that arise with all previous studies are the varying doses along with inadequate sample sizes. The limitations of previous investigations lie predominantly in their emphasis on chronic effects, or their exclusive focus on specific domains such as endurance sports and cognitive function. Consequently, there remains a notable scarcity of research delving into the acute impacts of wild ginseng extract on exercise performance, cognitive function, and fatigue recovery. Therefore, the primary objective of this study was to elucidate the effects of wild ginseng extract on exercise performance, cognitive function, and fatigue recovery.
This study is a double-blind, placebo-controlled crossover experiment with two trials (WG and placebo). Twelve healthy adult males (age=31±6.86 years) were randomly assigned to either WG or placebo groups with 2-week wash-out period. After a brief explanation of procedures, exercises, risks, and benefits associated with the study, each participant gave written consent before participation. The study was approved by the College's Institutional Review Board. Participants completed a questionnaire before the initiation of the experiment. Any of the participants who had any health issues, injuries, metabolic, cardiovascular, pulmonary disease, or intake of medication and or herbal supplementation were excluded from the trials.
Before the test, The investigators had a pre-familiarization that was conducted 3-5 days prior to the experiment. During the pre-familiarization, The investigators conducted a VO2 max test, body composition measurements, and cognitive function test. Body Composition. Body weight, height, percentage of body fat, blood pressure (mmHg), and heart rate (beats/min) were assessed. Body weight and height (weight in kilograms, height in meters) were measured using a wall stadiometer (PAT #290237, Novel Products, USA). Body fat (kg) was measured by skin fold (PAT#3,008,239, Beta Technology, USA). Blood pressure (mmHg) was measured using a blood pressure gauge (BP791IT, Omron, Japan). Heart rate (beats/min) was assessed by using a heart rate monitor (S120, Polar, USA). After the pre-familiarization, the experiments began. A Korean wild ginseng extract drink or placebo was given 90 minutes before the cycling exercise began. Power, strength, and cognitive function tests were conducted before, during, and after the experiment.
Composition of WG and Placebo Ingredient Ginseng Drink (%) Placebo (%) Korea Wild Ginseng Extract 0.25 0.00 Soy Powder 1.5 1.5 Almond Paste 1.5 1.5 Isomaltooligosaccharide 1.0 1.0 Fructooligosaccharide 0.75 0.75 Refined Salt 0.95 0.95 Scented Almond 0.05 0.05 Xanthan Gum 0.95 0.95 Sodium Bicarbonate 0.95 0.95 Soybean Extract 0.5 0.5 Water 93.15 93.15 Scented Ginseng 0.00 0.25 Caramel Coloring 0.00 0.06
VO2 max test: The participants were initially tested on a cycle ergometer to determine their maximal aerobic capacity (VO2 max) to accurately prescribe exercise intensities for endurance performance. During the VO2 max test, the participants exercised on cycle ergometer (894E, Monark, Sweden) with an initial work rate equal to 60 W and a pedaling rate of 60 revolutions per minute (rpm) for 2 minutes. Thereafter, the work rate increased by 30W every 2 minutes until the participant reached exhaustion, which was determined when participants met at least 2 of the following conditions: (a) inability to keep up the pedaling rate of 60 rpm for more than 5 seconds with verbal encouragement, (b) respiratory exchange ratio (RER) 1.10, (c) rating of perceived exertion (RPE) ≧19 (Borg 6-20 scale), or (d) volitional fatigue.
Cycling exercise: The participants performed the cycling exercise to assess endurance performance for 30 minutes at 70-75% of VO2 max. The cycle ergometer (984E, Monark, Sweden) was used to perform the cycling exercise.
Exercise Performance measurements Power: Power (Watts/kg) was evaluated by peak (average) power test using automatic Powercycle (Powercycle, USA). The participants performed a 2-minute warm-up by cycling at 100 to 120 repetitions per mins (rpm) with a power of 100 to 120 Watts. They performed four bouts of maximal acceleration for approximately 3 to 4 seconds on a verbal command with standardized encouragement. Data was recorded for 6.5 crank revolutions. The length of seat height was selected by each participant.
Strength: Isometric knee extensor and flexor strength (kg) was measured by a muscle testing system (Lafayette, USA). The participants sat on the table in supine position, and the knee and hip are positioned 90 degrees. The participants were instructed to remain seated and place both hands on the table. The dynamometer force pad was placed proximal to the ankle joint, and the knee extensor strength was quantified in pound force. All participants performed two maximal trials for 3 to 5 seconds with a 30 second rest interval. The higher value of two trials was recorded with normalized as a direct percentage of body weight (%BW).
Endurance performance: The participant performed the 10-mile time trial to assess endurance performance (second) using cycle ergometer. The cycle ergometer (984E, Monark, Sweden) was used to perform the time trial cycling. The workload was standardized for each participant by setting the resistance to achieve 70% VO2 max. Participants received standard encouragement to complete the time trial as quickly as possible and the time to complete the 10-mile distance was recorded.
Blood Analysis Glucose, IL-6, myoglobin, and total antioxidant capacity (TAC) were measured using about 2.5- 3 ml of blood withdrawn from an antecubital vein before, during, and after the cycling performances. The total volume of blood withdrawn per test was less than 34 ml. Therefore, total amount of blood withdrawn for all tests was less than 136 ml over the 44 days of experimental period (34 ml x 4 tests = 136 ml) A trained phlebotomist used the same standardized procedure used in doctors' offices and labs to collect blood. All blood samples were drawn into a tube containing ethylenediamine tetra-acetic acid (EDTA) to prevent coagulation. The blood was centrifuged, and the upper layer of plasma was transferred into a conical tube and stored at -20°C. Plasma lactate was then analyzed by lactic dehydrogenase enzymatic method (Sigma, USA). Serum was analyzed for glucose, IL-6, myoglobin, and total antioxidant capacity (TAC). Glucose level was analyzed by oxidase/Trinder endpoint method (Fisher, USA). IL-6 was analyzed by commercially available enzyme-linked immunosorbent assay (ELISA, EMD Millipore, Germany). Myoglobin was analyzed by enzyme immunoassay (ELISA, Biocheck, USA). Total antioxidant capacity (TAC) was analyzed using an antioxidant assay kit. All measurements were performed in duplicate.
Cognitive Performance To assess cognitive function, psychomotor vigilance task (PVT) and delayed-match-to-sample task (DMS) were taken before and after each exercise. The PVT test is composed of 40 trials for 5 minutes to assess mean reaction time (msec). The DMS was taken 20 minutes with 20 trials to assess memory.
Fatigue Fatigue rates were measured utilizing a rate of perceived exertion (RPE), scale of muscle soreness, and a fatigue questionnaire that was provided.
Inclusion Criteria:
Exclusion Criteria:
• Having health problems, injuries, metabolic, cardiovascular, or pulmonary disease.