Investigating the effects of pine back extract and black currants on the athletic performance of endurance athletes.
Investigating the efficacy of pine bark extract and black currant supplements on athletic performance in endurance athletes.
University of Otago, Department of Physiology
26 participants
Feb 13, 2025
Interventional
Conditions
Summary
The primary aim of this study is to determine if two commercially available supplements can improve athletic performance by enhancing VO2max (a measure of aerobic capacity), submaximal substrate utilization, lung function, muscle oxygenation, nitric oxide levels, and blood lactate levels. We hypothesize that these supplements, which are typically used to promote health and longevity in older or diseased populations, can also provide a competitive edge to athletes by improving various physiological functions and performance metrics.
Eligibility
Inclusion Criteria41
- Endurance Athletes:
- Cyclists (Road, Track, or Mountain bike)
- Triathletes/Duathletes
- Long Distance Runners
- a) Endurance Discipline Requirement:
- Athletes competing within A or B grades regionally or nationally in endurance disciplines such as cycling, triathlon, duathlon, or long-distance running will be selected to ensure consistency. Amateurs with low baseline aerobic capacities often show more significant improvements in VO2max, potentially skewing the results. Selecting athletes at this competitive level provides a more reliable baseline for evaluating the effects of administered supplements.
- b) Exercise Testing Modality:
- All athletes will complete exercise testing on a cycle ergometer. This ensures uniformity in testing procedures and facilitates direct comparison of results.
- Biological Sex:
- Biological Male
- Biological Female
- a) Biological Sex:
- Including an even spread of biological males and females ensures a comprehensive
- understanding of supplement effects across sexes. Sex differences in metabolism,
- cardiovascular function, and exercise response may influence study outcomes, making
- it essential to include a diverse participant pool. Aiming for equal representation of male
- and female participants enhances validity by reducing the potential for bias and ensures
- a balanced assessment of supplement efficacy across sexes
- b) Menstruation Monitoring:
- Female participants will be selected based on menstrual status. Regular menstruation
- indicates normal endocrine function, so these participants will be included in this study.
- To ensure consistency in hormonal fluctuations, menstrual cycles of female participants
- will be monitored, and testing will be conducted at consistent phases of their cycles. Any
- non-menstruating females on birth control will also be included but will not require the
- same monitoring as they will observe a consistent hormonal status throughout the study
- period.
- Age:
- Males: 20-50
- Females: 20-35
- a) Cardiovascular Risk Mitigation:
- Setting age limits for males (20-50) and females (20-35) reduces the risk of cardiovascular complications during exercise testing. Individuals above these age brackets may have underlying cardiovascular conditions or decreased exercise tolerance, increasing the likelihood of adverse events during physical exertion. This age limit also helps to exclude any biological females in perimenopause, who may exhibit hormonal fluctuations affecting exercise performance.
- b) Aerobic Fitness Control:
- Age can significantly impact aerobic fitness, so including participants within specific age ranges allows for better control of age-related physiological changes. This ensures a more homogeneous sample and facilitates accurate comparison of results across individuals.
- Ability to Provide Informed Consent
- total VO2max tests
- total submaximal exercise tests
- total spirometry tests
- total diffusion capacity tests
- Daily supplementation for 2 weeks
- a) Ability to Provide Informed Consent:
- Participants must possess the capacity to understand and consent to the requirements of the study, including exercising to failure in four total VO2max tests, two diffusion capacity tests in total (2 weeks apart), and taking a daily supplement for 2 weeks. This requires comprehension of the purpose, procedures, potential risks, and benefits of the study. Providing informed consent demonstrates the participant's willingness to engage in the study voluntarily and signifies their understanding of the protocol's demands. Ensuring participants can provide informed consent upholds ethical research standards, protects participant autonomy, and facilitates adherence to the study's rigorous protocol, promoting the validity and reliability of the research findings.
Exclusion Criteria37
- Antioxidant Supplementation:
- a) Exclusion of Participants Supplementing with Antioxidants:
- Individuals currently supplementing with antioxidants, including green tea and similar
- substances, are excluded unless willing to abstain from supplementation for a specified
- washout period (typically 3-4 weeks). This exclusion is implemented to avoid potential
- interference of antioxidant supplementation with the intended effects of the
- administered supplement on aerobic fitness.
- Medical Considerations:
- a) Exclusion of Participants with Medical Conditions:
- Individuals with pre-existing medical conditions that could affect exercise performance or safety are excluded from participation. These will be determined based on responses to the Physical Activity Readiness Questionnaire 2024 (Warburton et al., 2011). This ensures that participants are free from conditions that may confound study results or pose increased risk during physical activity.
- b) Exclusion of Pregnant Participants:
- Pregnancy introduces physiological changes that may affect exercise tolerance, cardiovascular responses, and hormonal status. Excluding pregnant individuals ensures participant safety and minimizes potential risks associated with exercise testing during pregnancy.
- c) Recent Major Illness or Surgery:
- Excluding individuals who have recently undergone major surgery or experienced significant illness ensures that participants are in stable health condition and minimizes potential complications during exercise testing.
- d) Medication Use:
- Screening for medication use, beyond hormonal therapy and antioxidants, may be
- necessary to identify potential medications that could influence exercise performance or
- physiological responses. In particular, asthma medications will be excluded as they can
- interfere with lung function measures such as spirometry and diffusion capacity.
- Excluding participants on certain medications helps maintain the integrity of the study
- results.
- Inability To Provide Informed Consent
- a) Exclusion of Participants unable to provide informed consent:
- Participants must possess the capacity to comprehend and consent to the VO2max test protocol, agree to undergo two blood draws, multiple finger or ear lobe pricks, and perform exercise until failure. This requires understanding the purpose, procedures, potential risks, and benefits of the test. Inability to provide informed consent may stem from cognitive impairment, language barriers, or legal incapacitation, preventing individuals from fully understanding and consenting to the requirements of the study.
- Excluding participants unable to provide informed consent safeguards ethical research conduct and ensures participant autonomy and welfare. It also guarantees adherence to the study's rigorous protocol, which includes blood sampling and maximal exercise testing.
- Biological Sex
- a) Exclusion of Hormonal Therapy:
- Excluding individuals on hormonal therapy ensures that the effects of these medications
- on physiological parameters, including VO2max, are minimised. Hormonal therapies can
- influence metabolism, cardiovascular function, and exercise performance, potentially
- confounding the study results. Females on oral contraceptives will be accepted for the
- study. However, athletes on anabolic or steroidal agents will not be included to avoid any
- potential confounding effects on the study outcomes.
- b) Menstruation Monitoring:
- Female participants who have lost their periods due to conditions such as Relative
- Energy Deficiency in Sport (RED-S) will be excluded from the study to maintain
- homogeneity in the sample and avoid potential confounding effects on study outcomes.
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Interventions
There will be two interventional groups, both of which will receive one of two different supplements for 2 weeks in total. The two supplements are: Zestt Wellness's Liquid Breathe +, and Plasmaide. 1. Breathe + by Zestt Wellness Actives: Boysenberry and blackcurrant, japonica saphora’s flavonoid quercetin, and probiotic BLISK12. Full Ingredient List: Boysenberry and blackcurrant, japonica saphora’s flavonoid quercetin, and probiotic BLISK12. Dosage: 35mL per day, 1-2 hours before exercise, containing: Anthocyanins (boysenberry and blackcurrant): 2625 mg, Quercetin: 175 mg, Chelated zinc: 5.25 mg, UMF 20+ Manuka honey: 175 mg. 2. Plasmaide by Plasmaide: Actives: Pinus pinaster stem bark extract. Full Ingredient List: Water, Emulsifier (Xanthan Gum) (E415), Sodium Chloride, Black Carrot Extract, Southern Fulvic Acid, Watermelon Flavour, Acidity Regulator (Citric Acid) (E330), Pine Bark Extract, Preservatives (E202, E211), Sweetener (Steviol Glycosides). Dosage: 2 packets (90 mL total) per day (1 packet 30 to 60 minutes before and after exercise). Pinus pinaster stem bark extract equivalent to dry stem bark 520g/90 mL (1 serving: 260g/45ml). Participants will be asked to continue to undertake their usual and prescribed training programs throughout the study. Before VO2max and submaximal exercise testing, the participant will be well rested and would have refrained from intense exercise for at least 24 hours. All four exercise tests will be conducted at similar times of the day for each participant. They will be normally hydrated and would have refrained from taking any non-habituated stimulants, supplements, or medications, and refrain from eating a large meal within 2-3 hours of the test. Participants will also be asked to abstain from vape or cigarette smoking 4 hours before exercise, along with alcohol 12 hours before each test. Patients will perform all four exercise tests in their daily habituated state to preserve normalcy and establish a reliable baseline for any exercise testing. This includes preserving normal sleep routines, medications, and food and coffee consumption. These requirements will be advised during recruitment, prior to any exercise testing. Participants will be asked to return their empty bottles of supplement upon their final exercise test.
Locations(1)
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ACTRN12625000302459