Echinacea-based dietary supplement does not increase maximal aerobic capacity in endurance-trained men and women

Purpose: Determine if an echinacea-based dietary supplement (EBS) provided at two different doses (a regular dose (RD) - 8,000mg/d vs. a double dose (DD) - 16,000mg/d) would increase erythropoietin (EPO) and other blood markers involved in improving aerobic capacity and maximal oxygen consumption (VO2max) in endurance-trained men. Secondly, to determine if any sex differences exist between male and female endurance-trained athletes. Methods: Forty-five endurance athletes completed three visits during a 35-day intervention. Participants were randomized into placebo (PLA) (n=8 men, n=7 women), RD of EBS (n=7 men, n=8 women), or DD of EBS (n=15 men) for the 35-day intervention period. At baseline, weight, body composition, and VO2max were measured. Blood was drawn to measure EPO, ferritin, red blood cells, white blood cells, hemoglobin, and hematocrit. At the mid-intervention visit blood was collected. At the post-intervention visit, all measurements from the baseline visit were obtaine