Guayusa Extract on Exercise Training
Study Details
Study Description
Brief Summary
Guayusa extract is a caffeinated Amazonian 'super-leaf' belonging to the holly species that contains a very unique blend of polyphenol antioxidants and caffeine (~20% caffeine, 30% chlorogenic acids, 5% catechins). It is also remarkably low in tannins which are responsible for the bitter taste found in most teas - giving it a sweet flavor profile. As such, it is marketed as an ingredient that can help support energy and performance with potential health-related benefits due to its antioxidant properties. Indeed, ingredients such as these are often consumed by individuals prior to exercise in order to help improve exercise performance, or otherwise to support health-related goals. Whereas several studies have suggested that caffeine and chlorogenic acid consumption may improve performance, mood, and concentration, and some evidence in animals have linked catechin consumption to improved health outcomes, no studies have previous studied whether guayusa extract supplementation helps to support exercise performance in humans. In this study, we will test the whether dietary supplementation with the botanical organic guayusa extract helps support (1) the desire to exercise and exercise performance throughout a 6-week high intensity exercise training program, and thus (2) helps support the physiological adaptations (including body composition, fasting metabolic biomarkers, blood pressure and heart rate, submaximal and maximal exercise performance and fuel metabolism, and changes in the gut microbiome/mycobiome) to a 6-week high intensity exercise training program.
Question 1: Does organic guayusa extract supplementation support the desire to train and training load in physically-active women performing a high-intensity exercise training program?
Question 2: Does organic guayusa extract supplementation support physiological adaptation to exercise (including body composition, fasting metabolic biomarkers, blood pressure and heart rate, submaximal and maximal exercise performance and fuel metabolism, and changes in the gut microbiome/mycobiome) in physically-active women performing a high-intensity exercise training program?
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
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N/A |
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Experimental: Organic Guayusa Extract + High Intensity Exercise Participants will consume an organic guayusa extract supplement that contains caffeine and antioxidants each day for 6 weeks while completing the exercise training program on 3 days/week. On days that participants exercise, they will consume the supplement 30-60 minutes before exercise training. On days they do not exercise, they will consume the capsules upon waking. |
Dietary Supplement: Organic Guayusa Extract
Supplementation: Participants will supplement daily with organic guayusa extract, which is a caffeinated Amazonian 'super-leaf' belonging to the holly species that contains a very unique blend of polyphenol antioxidants and caffeine (~20% caffeine, 30% chlorogenic acids, 5% catechins) during 6 weeks of high intensity exercise training. Investigators and participants will be blinded to condition.
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| Placebo Comparator: Placebo + High Intensity Exercise Participants will consume a placebo consisting of maltodextrin each day for 6 weeks while completing the exercise training program. The placebo will be provided in capsule identical in appearance to the active supplement. On days that participants exercise, they will consume the placebo 30-60 minutes before exercise training. On days they do not exercise, they will consume the capsules upon waking. |
Dietary Supplement: Placebo
Participants will supplement daily with placebo (maltodextrin). Investigators and participants will be blinded to condition.
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Outcome Measures
Primary Outcome Measures
- Desire to Exercise [Throughout 6-week training period.]
Desire to Exercise will be assessed Primarily via the Assessment of Exercise Readiness using a 41-item Exercise Readiness Questionnaire.
- Exercise Adherence [Throughout 6-week training period.]
Exercise training session adherence will be assessed across all exercise training sessions as a primary quantitative indicator of desire to exercise. Adherence will be assessed as the actual number of completed exercise sessions among participants in each group relative (i.e., percent, %) to the number of total planned exercise sessions. Group differences in session adherence will be compared by chi squared tests.
- Exercise Training Load [Throughout 6-week training period.]
Resistance Exercise Training Volume (normalized to bodyweight) will be quantified in each resistance training workout (2x/week) and used as a quantitative indicator of exercise performance/effort.
Secondary Outcome Measures
- Desire to Exercise Secondary Measures [Throughout 6-week training period.]
Secondary assessments of Desire to Exercise will include visual analog scales (range 0 - 50, with 0 indicating lower desire and 50 indicating higher desire) used to assess readiness immediately before exercise sessions to "exercise right now", to "invest physical energy right now" and to "invest mental energy right now".
- Exercise Training Performance [Throughout 6-week training period.]
Secondary assessments of exercise training performance will include performance during a) a weekly airbike interval exercise session (Avg W), b) a weekly 500 m row (time to completion, Avg W), and c) the time (min) taken to complete the weekly metabolic conditioning workout.
- VO2peak [baseline, <7 days after completing the intervention]
VO2peak will be assessed during a ramp test on a electronically-braked cycle ergometer performed to volitional exhaustion with pulmonary gas exchange analysis.
- Submaximal Exercise Fat Oxidation [baseline, <7 days after completing the intervention]
Submaximal Exercise Fat Oxidation (%) will be assessed during exercise at a fixed power (i.e., 75W) on an electronically-braked cycle ergometer with pulmonary gas exchange analysis.
- Submaximal Exercise Blood Pressure [baseline, <7 days after completing the intervention]
Submaximal Systolic and Diastolic Exercise Blood Pressure (mmHg) will be assessed during exercise at a fixed power (75W) on an electronically-braked cycle ergometer.
- Fasting metabolic biomarkers [baseline, <7 days after completing the intervention]
Total cholesterol, HDL-cholesterol, LDL-cholesterol, non-HDL cholesterol, triglycerides, glucose, insulin, c-peptide, GLP-1, GIP
- Fasting total cholesterol [baseline, <7 days after completing the intervention]
Total cholesterol will be assessed from a fasting blood sample.
- Fasting HDL-cholesterol [baseline, <7 days after completing the intervention]
HDL-cholesterol will be assessed from a fasting blood sample.
- Fasting non-HDL cholesterol [baseline, <7 days after completing the intervention]
Non-HDL cholesterol will be assessed from a fasting blood sample.
- Fasting triglycerides [baseline, <7 days after completing the intervention]
Triglycerides will be assessed from a fasting blood sample
- Fasting Glucose [baseline, <7 days after completing the intervention]
Glucose will be assessed from a fasting blood sample
- Fasting insulin [baseline, <7 days after completing the intervention]
insulin will be assessed from a fasting blood sample
- Fasting c-peptide [baseline, <7 days after completing the intervention]
Fasting c-peptide will be assessed from a fasting blood sample
- Fasting GLP-1 [baseline, <7 days after completing the intervention]
Fasting GLP-1 will be assessed from a fasting blood sample
- Fasting GIP [baseline, <7 days after completing the intervention]
Fasting GIP will be assessed from a fasting blood sample
- Fasting IL-6 [baseline, at 1 week during the intervention, <7 days after completing the intervention]
IL-6 will be assessed from a fasting blood sample
- Fasting IL-10 [baseline, at 1 week during the intervention, <7 days after completing the intervention]
IL-10 will be assessed from a fasting blood sample
- Fasting TNFa [baseline, at 1 week during the intervention, <7 days after completing the intervention]
TNFa will be assessed from a fasting blood sample
- Fasting triiodothyronine (T3) [baseline, at 1 week during the intervention, <7 days after completing the intervention]
Triiodothyronine (T3) will be assessed from a fasting blood sample
- Fasting thyroxine (T4) [baseline, at 1 week during the intervention, <7 days after completing the intervention]
Thyroxine (T4) will be assessed from a fasting blood sample
- Fasting Progesterone [baseline, at 1 week during the intervention, <7 days after completing the intervention]
Progesterone will be assessed from a fasting blood sample
- Fasting Testosterone [baseline, at 1 week during the intervention, <7 days after completing the intervention]
Testosterone will be assessed from a fasting blood sample
- Fasting Estrogen [baseline, at 1 week during the intervention, <7 days after completing the intervention]
Estrogen will be assessed from a fasting blood sample
- Fasting Cortisol [baseline, at 1 week during the intervention, <7 days after completing the intervention]
Cortisol will be assessed from a fasting blood sample
- Fasting Adiponectin [baseline, <7 days after completing the intervention]
Adiponectin will be assessed from a fasting blood sample
- Fasting Leptin [baseline, <7 days after completing the intervention]
Leptin will be assessed from a fasting blood sample
- Fasting Adipsin [baseline, <7 days after completing the intervention]
Adipsin will be assessed from a fasting blood sample
- Fasting Lipocalin [baseline, <7 days after completing the intervention]
Lipocalin will be assessed from a fasting blood sample
- Fasting Plasminogen activator inhibitor-1 (PAI-1) [baseline, <7 days after completing the intervention]
Plasminogen activator inhibitor-1 (PAI-1) will be assessed from a fasting blood sample
- Fasting Resistin [baseline, <7 days after completing the intervention]
Resistin will be assessed from a fasting blood sample
Other Outcome Measures
- Rating of Perceived Exertion [Throughout 6-week training period.]
RPE will be assessed following each exercise session to determine subjective effort for each session on a scale of 1-10, where 1 is lowest perceived effort (e.g., rest) and 10 is greatest perceived effort.
Eligibility Criteria
Criteria
Inclusion Criteria:
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Females
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18-45 years, inclusive
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Physically active >=150 min/wk Moderate Intensity or >=75 min/wk Vigorous Intensity PA) for >=3 months
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BMI < 35 kg/m2
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Otherwise healthy and ready to participate in an exercise program as indicated by responses on the 2021 Physical Activity Readiness Questionnaire Plus (PAR-Q+)
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Habitual caffeine consumption <=200 mg/day OR 2-week washout of current caffeine usage prior to participation
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No current dietary supplementation OR 2-week washout of current supplement usage prior to participation
Exclusion Criteria:
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Current injury or illness that precludes exercise participation
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Current nicotine or cannabis use
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Use of prescription ADD/ADHD, anti-depressant, or other central acting medication, or previously diagnosed ADD/ADHD, clinically depressed, or generalized anxiety disorder
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Current taking prescription stimulants (i.e., Adderall, Ritalin, Vyvanse, etc.)
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Participants with a history of metabolic, hepatorenal, musculoskeletal, autoimmune, or neurologic disease; or currently taking thyroid, hormonal, hyperlipidemic, hypoglycemic, anti-hypertensive, anti-inflammatory, or anti-coagulant medications.
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Treated for Metabolic Syndrome or having been clinically diagnosed with, or taking medication for a cardiometabolic-disorder (e.g., Pre-diabetes, Type II diabetes, high blood pressure, obesity, hypercholesterolemia, etc.)
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Currently pregnant or lactating
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Diagnosed allergy to any ingredient present within the study treatments
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Current competitive NCAA athlete
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Inability or unwillingness to comply with the controls and conditions of the study
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | Integrative Laboratory of Applied Physiology and Lifestyle Medicine | Iowa City | Iowa | United States | 52242 |
Sponsors and Collaborators
- Nathaniel Jenkins
Investigators
None specified.Study Documents (Full-Text)
None provided.More Information
Publications
None provided.- 202110443