Efficacy of a Botanical Supplement with Concentrated Echinacea purpurea for Increasing Aerobic Capacity

The present investigation evaluated the efficacy of a botanical supplement that delivered a concentrated dose of Echinacea purpurea (8 grams day？1). The participants were 13 apparently healthy, recreationally active college students (VO2 max: 51？mL O2/kg*min). The participants were provided with a 30-day supplementation regime. Data regarding maximum aerobic capacity was collected through pre- and posttesting surrounding the 30-day supplementation regime. The participants were instructed to maintain normal levels of physical activity and exercise during the experimental period. The levels of physical activity and exercise were monitored via the Leisure and Physical Activity Survey. The participants did not report any significant increases in aerobic physical activity or exercise during the supplementation period. Paired samples t-test analysis did not reveal a significant difference in maximum aerobic capacity, , . Presupplementation maximum aerobic capacity ( , ) was similar to postsupplementation values ( , ). This study suggests that botanical supplements containing a concentrated dose of Echinacea purpurea is not an effective intervention to increase aerobic capacity of recreationally active individuals. 1. Introduction Maximal oxygen consumption (VO2 max) is the amount of oxygen the human body can utilize in muscles and/or tissues. VO2 max testing is the laboratory standard for assessing aerobic fitness [1]. Low aerobic fitness is associated with congestive heart failure, anemia, and obstructive pulmonary disease [2]. VO2 max is determined by both the capacity of oxygen delivery to the blood stream and the capacity of oxygen extraction from blood [3]. Botanical supplements have been studied for decades, some of which have been associated with health or performance benefits [4]. Echinacea is an herbal supplement that is derived from the North American Purple Coneflower plant and has shown some potential mechanisms that, with supplementation, could augment oxygen transport. Echinacea supplementation was found to increase VO2 max likely through an increase in the number and size of red blood cells, hemoglobin, and hematocrit associated with increases in serum erythropoietin [1]. Recent research suggests Echinacea induced erythrocythemia and VO2 max results in an increase in serum erythropoietin (EPO) [1, 5]. This glycoprotein hormone, primarily produced in the kidneys, regulates red blood cell production. EPO improves exercise performance by increasing oxygen blood transport, which results in a greater VO2 max [6]. The increase in red blood cell mass