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).

Study Overview

• Status: Completed
• Conditions: Exercise Performance
• Intervention / Treatment: Dietary supplement: Placebo of calcium; Dietary supplement: Rhodiola; Dietary supplement: Rhodiola and Cordyceps

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Actual): 13
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • California
    • San Luis Obispo, California, United States, 93407
      • California Polytechnic State University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 16 years to 28 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Triple

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Placebo of calcium; Participants will consume 250 mg of calcium	Dietary supplement: Placebo of calcium; Ingestion of 250 mg of calcium
Experimental: Rhodiola; Participants will consume 250 mg of Rhodiola	Dietary supplement: Rhodiola; Ingestion of 250 mg of Rhodiola
Experimental: Rhodiola and Cordyceps; Participants will consume a combination of 250 mg of Rhodiola and 225 mg of Cordyceps	Dietary supplement: Rhodiola and Cordyceps; Ingestion of 250 mg of Rhodiola and 225 mg of Cordyceps

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
VO2 max	Maximum oxygen consumption using the Bruce Protocol	90 minutes after baseline

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Gastrointestinal symptoms questionnaire	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.	Baseline, 90 minutes, 110 minutes
Blood glucose	Plasma glucose assessed by finger stick	Baseline, 90 minutes, 110 minutes
Blood lactate	Plasma lactate assessed by finger stick	Baseline, 90 minutes, 110 minutes

Collaborators and Investigators

• Sponsor: California Polytechnic State University-San Luis Obispo
• Investigators: Principal Investigator: Todd Hagobian, PhD, California Polytechnic State University-San Luis Obispo

Study record dates

Study Major Dates

• Study Start (Actual): May 1, 2019
• Primary Completion (Actual): December 1, 2019
• Study Completion (Actual): December 1, 2019

Study Registration Dates

• First Submitted: April 24, 2019
• First Submitted That Met QC Criteria: April 25, 2019
• First Posted (Actual): April 29, 2019

Study Record Updates

• Last Update Posted (Actual): January 27, 2021
• Last Update Submitted That Met QC Criteria: January 25, 2021
• Last Verified: January 1, 2021

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Calcium-Regulating Hormones and Agents; Calcium
• Other Study ID Numbers: CPKINE454

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No