Cordyceps and Rhodiola are two common herbal supplements marketed and consumed as adaptogens to athletes with regard to enhanced performance. The effects of these supplements has been well studied in animals but whether or not the same effects translate to humans is still unclear. Thus, the primary purpose of this study is to determine whether combined supplementation of Rhodiola and Cordyceps, compared to Rhodiola alone and placebo, will demonstrate a greater improvement in oxygen consumption (ie. VO2 max).

Herbal supplements are consumed worldwide with surveys approximating five billion dollars spent annually by consumers in the United States alone. Herbal supplements, such as Rhodiola and Cordyceps, both of which are considered to be adaptogens, remain popular among athletes. These adaptogens act as antioxidants, which have been speculated to confer endurance performance benefits by delaying muscle fatigue via the attenuation of muscle damage accumulation and its related by-products during prolonged or exhaustive exercise. Nevertheless, previous research investigating the individual effects of Rhodiola and Cordyceps on aerobic training performance remain equivocal. Moreover, literature elucidating the potential additive effects of Rhodiola and Cordyceps in human subjects are scarce. Therefore, the purpose of the present study is to determine the acute, additive influence of oral Rhodiola and Cordyceps supplementation on VO2 max, with secondary variables of interest being plasma glucose and lactate concentration, and measures of gastrointestinal distress.

Inclusion Criteria:

• Body Mass Index between 18.5 and 35 kg/m^2
• Non-smoking (assessed by Health History Questionnaire)
• English-speaking
• Regular participation in physical activity (>4 hours per week)

Exclusion Criteria:

• Medical conditions that prohibit physical activity (assessed by Health History Questionnaire)
• Pregnant women or women expecting/trying to become pregnant
• BMI greater than or equal to 35 kg/m^2
• Current smoker (assessed by Health History Questionnaire)