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Completed

NCT Number: NCT03929575

Effects of Herbal Supplements on Endurance Exercise Performance

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).

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Key information

Conditions

Exercise Performance

Age range

18 year–30 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

California Polytechnic State University

San Luis Obispo, California, 93407, United States

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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)

Treatment and study plan

Placebo of calcium

Dietary Supplement

Ingestion of 250 mg of calcium

Rhodiola

Dietary Supplement

Ingestion of 250 mg of Rhodiola

Rhodiola and Cordyceps

Dietary Supplement

Ingestion of 250 mg of Rhodiola and 225 mg of Cordyceps

Primary outcomes

  1. VO2 max

    Time frame: 90 minutes after baseline

    Maximum oxygen consumption using the Bruce Protocol

Secondary outcomes

  1. Gastrointestinal symptoms questionnaire

    Time frame: Baseline, 90 minutes, 110 minutes

    Section 1 contains 6 questions assessing upper abdominal problems (reflux, heartburn, bloating, cramps, vomiting, and nausea). Section 2 contains 7 questions assessing lower abdominal problems (intestinal cramps, flatulence, urge to defecate, left abdominal pain, right abdominal pain, loose stool, and diarrhea). Section 3 contains 4 questions assessing systematic problems (dizziness, headache, muscle cramp, and urge to urinate). Each of the 17 questions is answered using a 10-point scale ranging from 0 (no problem at all) to 10 (the worst it has ever been). Each of the 3 sections will be scored separately. Section 1 will be scored on a scale of 0-60. Section 2 will be scored on a scale of 0-70. Section 3 will be scored on a scale of 0-40.

  2. Blood glucose

    Time frame: Baseline, 90 minutes, 110 minutes

    Plasma glucose assessed by finger stick

  3. Blood lactate

    Time frame: Baseline, 90 minutes, 110 minutes

    Plasma lactate assessed by finger stick

Sponsors and collaborators

Lead sponsor

California Polytechnic State University-San Luis Obispo

Other

Registry information

Important dates

Study start
2019
Primary completion
2019
Study completion
2019
First posted
Apr 29, 2019
Registry last updated
Jan 27, 2021

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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