Improved Running Economy and Maximal Oxygen Consumption After 4-Weeks of Oral Echinacea Supplementation

Abstract

Echinacea is an herbal supplement primarily utilized as an immunostimulant. Evidence from animal and cell culture models indicate that Echinacea may increase oxygen transport capacity. PURPOSE: The purpose of this investigation was to determine the effects of four-weeks of oral Echinacea supplementation on erythropoietin, red blood cell count, running economy, and VO2 max. METHODS: Twenty-four males (aged 24.9 ± 4.2 yr, height 178.9 ± 7.9 cm, weight 87.9 ± 14.6 kg, body fat 19.3 ± 6.5 %) were supplemented with either 8000 mg-d-1 of Echinacea (ECH) (n=12) or a placebo (PLA) (n=12). Blood samples were collected prior to and every 7-d during supplementation and analyzed for erythropoietin and red blood cells. Maximal graded exercise tests were administered to measure VO2 max, running economy, and heart-rate responses. Significant between groups differences were determined from ANOVA with significance set at P ≤ 0.05. RESULTS: Erythropoietin increased significantly in ECH at days 7 (15.75 ± 0.64 vs. 10.01 ±0.73mU·mL-l), 14 (18.88 ± 0.71 vs. 11.02 ± 0.69 mU·mL-1), and 21 (16.06 ± 0.55 vs. 9.20 ± 0.55 mU·mL-1). VO2 max increased significantly in ECH (1.47 ± 1.28 vs. -0.13 ± 0.52 %). Running economy improved significantly in ECH as indicated by a decrease in submaximal VO2 during the first 2 stages of the graded exercise test (Stage 1: −1.50 ± 1.21 vs. 0.60 ±1.95; Stage 2: −1.67 ± 1.43 vs. 0.01 ± 1.03%; ECH and PLA, respectively). CONCLUSION: These data suggest that Echinacea supplementation results in significant increases in erythropoietin, VO2max, and running economy. Supported by donations from Puritan's Pride, Holbrook, NY and the A.K. and E.G. Lucas Endowment for Faculty Excellence, Office of the Vice President for Research, The University of Southern Mississippi.