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

• Autores: Malcolm T. Whitehead, Tyler D. Martin, Timothy P. Scheett, Michael J. Webster
• Localización: Journal of strength and conditioning research: the research journal of the NSCA, ISSN 1064-8011, Vol. 26, Nº. 7, 2012, págs. 1928-1933
• Idioma: inglés
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• Resumen

  • 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.