34 research outputs found
Effect of Six Weeks of Oral \u3ci\u3eEchinacea purpurea\u3c/i\u3e Supplementation On Nitric Oxide Production
Echinacea purpurea, a purple coneflower plant of the compositae family (Asteraceae), is native to North America and commonly used as an herbal supplement to enhance immune function. Echinacea purpurea has been shown to stimulate macrophage activity which is a known stimulator of nitric oxide (NO) production. Echinacea purpurea supplementation (8,000 mg·d-1) in untrained (42.5 ± 1.6 mL·kg-1·min-1) males was shown to elicit a 63% increase (p \u3c 0.05) in serum erythropoietin (EPO) following two weeks of supplementation. This is supported in part by earlier findings which indicated that four weeks of Echinacea purpurea supplementation demonstrated a non-significant increase in maximal oxygen uptake (VO2max). It is plausible that Echinacea-induced EPO production may stimulate physiological responses independent of and/or in addition to erythropoiesis. There is also evidence suggesting EPO has vasculo-protective effects including the activation of endothelial nitric oxide synthase (eNOS). Based on these findings, a proposed non-hematological response to the Echinacea-induced increase in EPO could be enhanced NO production. The purpose of this investigation was to determine whether six weeks of oral Echinacea purpurea supplementation augmented NO production as a result of an Echinacea-induced increase in EPO and/or Echinacea-induced macrophage activity
Alteration of immune function in women collegiate soccer players and college students
The purpose of this study was to monitor the stress-induced alteration in concentrations of salivary immunoglobulin (S-IgA) and cortisol and the incidence of upper respiratory tract infections (URTI) over the course of a 9-week competitive season in college student-athletes and college students. The subjects consisted of 14 NCAA Division III collegiate female soccer athletes (19.8 ± 1.0 years, mean ± SD) and 14 female college students (22.5 ± 2.6 years). Salivary samples were collected for 9 weeks during a competitive soccer season. S-IgA and cortisol concentrations were determined by enzyme linked immunosorbent assay (ELISA). A training and performance questionnaire was given to the subjects every week, to record the subjects’ session rating of perceived exertion (RPE) for all the training, load, monotony and strain, as well as any injuries or illnesses experienced. The between groups ANOVA procedure for repeated measures showed no changes in salivary concentrations of IgA and cortisol. Chisquare analysis showed that during the 9-week training season injury and illness occurred at a higher rate among the soccer players. There was a significant difference at baseline between soccer and control SIgA levels (p ≤ 0.05). Decreased levels of SIgA and increases in the indices of training (load, strain and monotony) were associated with an increase in the incidence of illness during the 9-week competitive soccer season
Effectiveness of Glycerol as a Rehydrating Agent
On two occasions, 8 male subjects completed a dehydration protocol, immediately followed by a 180-min rehydration protocol, then a subsequent exercise bout. During each dehydration session, subjects lost 3.1 +/- 0.4% body weight (BW)following discontinuous exercise in the heat (40 degreesC, 33% rh). During the first 30 min of rehydration, subjects ingested either 1.0-g glycerol . kg body weight(-1) + 30% of the total rehydration water volume (GLY), or 30% of the total rehydration water volume without glycerol (CON). The five remaining ingestions (every 30 min) were equal to 14% of the remaining fluid volume and were identical in nature. Fluid volume ingested equaled fluid volume lost during dehydration. Following the 180 min rehydration period, subjects cycled (similar to 50% (V) over dot (2peak)) in the heat (40 degreesC, 33% rh) until volitional exhaustion. Three observations were made: (a) Following glycerol-induced rehydration, time to volitional exhaustion was greater during the subsequent exercise bout in the heat (CON: 38.0 +/- 2.0, GLY 42.8 +/- 1.0 min, p \u3c .05); (b) glycerol-induced rehydration significantly increased plasma volume restoration within 60 min and at the end of the 180-min rehydration period; and (c) total urine volume was lower and percent rehydration was greater following GLY, but neither was significantly different
The Effect of 4 Wk of Oral Echinacea Supplementation On Serum Erythropoietin and Indices of Erythropoietic Status
The purpose of this investigation was to determine whether echinacea supplementation results in alterations of erythroid growth factors and erythropoietic status. Twenty-four men age 24.9 +/- 4.2 y, height 1.7 +/- 0.8 m, weight 87.9 +/- 14.6 kg, and 19.3% +/- 6.5% body fat were grouped using a double-blind design and self-administered an 8000-mg/d dose of either echinacea (ECH) or placebo (PLA) in 5 x 400 mg x 4 times/d for 28 d. Blood samples were collected and analyzed for red blood cells (RBCs), hematocrit (Hct), hemoglobin (Hb), mean corpuscular volume, mean corpuscular hemoglobin content, prostaglandin E (2), ferritin, erythropoietin (EPO), interleukin 3 (IL-3), and granulocyte-macrophage-colony-stimulating factor using automated flow cytometry and ELISA. ANOVA was used to determine significant differences (P \u3c= 0.05). EPO was greater (P \u3c 0.001) in ECH at Days 7, 14, and 21 and reflected a 44%, 63%, and 36% increase, respectively. IL-3 was greater (P = 0.011) in ECH at Days 14 and 21, which indicated a 65% and 73% increase, respectively. These data indicate that ECH supplementation resulted in an increase in EPO and IL-3 but did not significantly alter RBCs, Hb, or Hct
Running Economy and Maximal Oxygen Consumption After 4 Weeks of Oral Echinacea Supplementation
Whitehead, MT, Martin, TD, Scheett, TP, and Webster, MJ. Running economy and maximal oxygen consumption after 4 weeks of oral Echinacea supplementation. J Strength Cond Res 26(7): 1928–1933, 2012—The purpose of this investigation was to determine the effects of 4 weeks of oral Echinacea (ECH) supplementation on erythropoietin (EPO), red blood cell (RBC) count, running economy (RE), and V[Combining Dot Above]O2max. Twenty-four men aged 24.9 ± 4.2 years, height 178.9 ± 7.9 cm, weight 87.9 ± 14.6 kg, body fat 19.3 ± 6.5% were grouped using a double-blind design and self-administered an 8,000-mg·d−1 dosage of either ECH or placebo (PLA) in 5 × 400 mg × 4 times per day for 28 days. Blood samples were collected and analyzed for RBCs and EPO using automated flow cytometery and enzyme-linked immunosorbent assay. Maximal graded exercise tests (GXTs) were administered to measure V[Combining Dot Above]O2max, RE, and heart-rate responses. Analysis of variance was used to determine statistically significant differences (P ≤ 0.05). The EPO increased significantly in ECH at 7 days (ECH: 15.75 ± 0.64, PLA: 10.01 ± 0.73 mU·ml−1), 14 days (ECH: 18.88 ± 0.71, PLA: 11.02 ± 0.69 mU·ml−1), and 21 days (ECH: 16.06 ± 0.55, PLA: 9.20 ± 0.55 mU·ml−1). V[Combining Dot Above]O2max increased significantly in ECH (ECH: 1.47 ± 1.28, PLA: −0.13 ± 0.52%). Running economy improved significantly in ECH as indicated by a decrease in submaximal V[Combining Dot Above]O2 during the first 2 stages of the GXT (stage 1: ECH −1.50 ± 1.21, PLA 0.60 ± 1.95%; stage 2: ECH −1.67 ± 1.43, PLA 0.01 ± 1.03%). These data suggest that ECH supplementation results in significant increases in EPO, V[Combining Dot Above]O2max, and running economy
Sodium Bicarbonate Supplementation Improves Hypertrophy-Type Resistance Exercise Performance
The aim of the present study was to examine the effects of sodium bicarbonate (NaHCO3) administration on lower-body, hypertrophy-type resistance exercise (HRE). Using a double-blind randomized counterbalanced design, 12 resistance-trained male participants (mean +/- A SD; age = 20.3 +/- A 2 years, mass = 88.3 +/- A 13.2 kg, height = 1.80 +/- A 0.07 m) ingested 0.3 g kg(-1) of NaHCO3 or placebo 60 min before initiation of an HRE regimen. The protocol employed multiple exercises: squat, leg press, and knee extension, utilizing four sets each, with 10-12 repetition-maximum loads and short rest periods between sets. Exercise performance was determined by total repetitions generated during each exercise, total accumulated repetitions, and a performance test involving a fifth set of knee extensions to failure. Arterialized capillary blood was collected via fingertip puncture at four time points and analyzed for pH, [HCO3 (-)], base excess (BE), and lactate [Lac(-)]. NaHCO3 supplementation induced a significant alkaline state (pH: NaHCO3: 7.49 +/- A 0.02, placebo: 7.42 +/- A 0.02, P \u3c 0.05; [HCO3 (-)]: NaHCO3: 31.50 +/- A 2.59, placebo: 25.38 +/- A 1.78 mEq L-1, P \u3c 0.05; BE: NaHCO3: 7.92 +/- A 2.57, placebo: 1.08 +/- A 2.11 mEq L-1, P \u3c 0.05). NaHCO3 administration resulted in significantly more total repetitions than placebo (NaHCO3: 139.8 +/- A 13.2, placebo: 134.4 +/- A 13.5), as well as significantly greater blood [Lac(-)] after the exercise protocol (NaHCO3: 17.92 +/- A 2.08, placebo: 15.55 +/- A 2.50 mM, P \u3c 0.05). These findings demonstrate ergogenic efficacy for NaHCO3 during HRE and warrant further investigation into chronic training applications
An Isoenergetic Very Low Carbohydrate Diet Improves Serum HDL Cholesterol and Triacylglycerol Concentrations, the Total Cholesterol to HDL Cholesterol Ratio and Postprandial Lipemic Responses Compared With a Low Fat Diet in Normal Weight, Normolipidemic Women
Very low carbohydrate diets are popular, yet little is known about their effects on blood lipids and other cardiovascular disease risk factors. We reported previously that a very low carbohydrate diet favorably affected fasting and postprandial triacylglycerols, LDL subclasses and HDL cholesterol (HDL-C) in men but the effects in women are unclear. We compared the effects of a very low carbohydrate and a low fat diet on fasting lipids, postprandial lipemia and markers of inflammation in women. We conducted a balanced, randomized, two-period, crossover study in 10 healthy normolipiclemic women who consumed both a low fat (\u3c30% fat) and a very low carbohydrate (\u3c10% carbohydrate) diet for 4 wk each. Two blood draws were performed on separate days at 0, 2 and 4 wk and an oral fat tolerance test was performed at baseline and after each diet period. Compared with the low fat diet, the very low carbohydrate diet increased (P +/- 0.05) fasting serum total cholesterol (16%), LDL cholesterol (LDL-C) (15%) and HDL-C (33%) and decreased serum triacylglycerols (- 30%), the total cholesterol to HDL ratio (- 13%) and the area under the 8-h postprandial triacylglycerol curve (-31 %). There were no significant changes in LDL size or markers of inflammation (C-reactive protein, interleukin-6, tumor necrosis factor-a) after the very low carbohydrate diet. In normal weight, normolipiclemic women, a short-term very low carbohydrate diet modestly increased LDL-C, yet there were favorable effects on cardiovascular disease risk status by virtue of a relatively larger increase in HDL-C and a decrease in fasting and,postprandial triaclyglycerols