The purpose of this study was three-fold. We wanted to (1) determine if supplementation with an echinacea-based dietary supplement (ECH) would increase several blood parameters that could affect oxygen carrying capacity in the body, (2) determine if ECH would increase VO2max in trained endurance athletes, and (3) examine the effectiveness of two different doses of the ECH on all outcome variables. We hypothesized that supplementation with ECH would increase oxygen carrying capacity (as measured by RBCs, EPO, ferritin, hemoglobin (Hb), and hematocrit (Hct) levels), improve VO2max, and that the maximum dose would be most effective at increasing these outcomes.