Impact of Cocoa Flavanols on Pulmonary Oxygen Uptake Kinetics and Exercise Tolerance in Sedentary Middle-aged Adults
Study Details
Study Description
Brief Summary
In recent years, there has been significant interest in dietary flavonoids (biologically active plant-derived compounds) as potential therapeutics. This is due to the capacity of flavonoids to enhance processes related to energy metabolism and cardiovascular health. We are interested in implementing a short-term supplementation regime (daily cocoa-flavanoid ingestion), in order to explore the possible beneficial effects of flavonoid-based interventions on responses to exercise. Hence, the objective of our study is to examine the impact of short term cocoa-flavanoid supplementation on processes related to energy use (oxygen utilisation). Our aim is to develop a novel intervention which improves cardiovascular health and enhances exercise tolerance.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
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N/A |
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Placebo Comparator: Placebo Placebo supplement, each capsule containing: 0mg total flavanols, matched for caffeine and theobromine content as experimental supplement (2.9 mg caffeine and 22.5 mg theobromine) and microcrystalline cellulose volume filler. Participants consume 4x capsules daily (2AM & 2PM after mixed meal for 7 days. |
Dietary Supplement: Placebo supplement
Microcrystalline filler, containing 0mg total flavanols.
|
| Experimental: Cocoa Flavanols Experimental supplement, each capsule containing: 316 mg CocoActiv (Naturex, Netherlands: 100mg total cocoa flavanols, 2.9 mg caffeine and 22.5 mg theobromine) and microcrystalline cellulose volume filler. Participants consume 4x capsules daily (2AM & 2PM) for 7 days. |
Dietary Supplement: Cocoa flavanols
Flavonoid-rich cocoa powder, containing 100mg total flavanols per 316mg.
|
Outcome Measures
Primary Outcome Measures
- Oxygen uptake kinetics [Over 3 week period (After 7 days of each intervention). Oxygen uptake measured for 9 minutes continuously during exercise bouts (3 min warm up period and 6 minutes of exercise transition)]
Oxygen uptake kinetics (including time constant, time delay and amplitude of the fundamental oxygen uptake response) will be determined by modelling oxygen uptake during exercise using a mono exponential function. The oxygen uptake data is measured on a breath-by-breath basis during exercise (on a cycle ergometer) using a gas analysis system and face mask. Oxygen kinetics will be measured during three moderate-intensity step exercise tests (at 80% of the gas exchange threshold) and during one severe-intensity (60%∆) step exercise test that is completed to failure.
- Exercise tolerance [Over 3 week period (After 7 days of each intervention).]
Participants capacity to exercise to the limit of tolerance, measured to the nearest second. Participants are instructed to exercise at a severe-intensity exercise load (representative of 60% ∆), on a cycle ergometer until volitional exhaustion.
Secondary Outcome Measures
- Heart rate [Over 3 week period (After 7 days of each intervention). Measured during the length of each exercise transition (9 minutes for each moderate intensity bout).]
Heart rate will be measured during moderate and severe-intensity exercise bouts, by short-range telemetry.
- Blood pressure [Over 3 week period (After 7 days of each intervention). Measured over 5 minutes before any exercise testing.]
Systolic and diastolic blood pressure will be assessed following 10 min of seated rest using an automated sphygmomanometer
- Blood lactate [Over 3 week period (After 7 days of each intervention). Measured immediately before and after exercise]
A finger prick blood sample will be taken to measure blood lactate pre- and post-exercise of each transition using a hand-held automated blood lactate analyser
- Physical activity and sedentary behaviour [Over 3 week period (In the 6 days preceding experimental testing)]
Physical activity levels will be assessed in the 6 days prior to visiting the laboratory by an accelerometer, worn on the hip during waking hours.
- Perceived workload [Over 3 week period (After 7 days of each intervention). Measured immediately before and after exercise]
Perceived mental workload will be measured pre and post exercise using NASA Task Load Index and BORG rating of perceived exertion scale.
Eligibility Criteria
Criteria
Inclusion Criteria:
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Aged 35-55 years
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Healthy (no known cardiovascular or metabolic disorders e.g. diabetes)
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Do not engage in regular structured physical training (i.e. less than two sessions for 60 minutes per week, for at least 1 year
Exclusion Criteria:
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Smokers
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Medical history of cardiovascular and/or metabolic disease, including diabetes and abnormal blood pressure
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Family history of cardiovascular disease
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Currently taking any medication
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Asthmatic
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Currently suffering from musculoskeletal injury
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Younger than 35 or older than 55 years old
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Known food allergies or special dietary requirements
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Currently taking any dietary supplements
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Currently engaging in >2 hours structured training per week
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | Research Institute for Sport & Exercise Sciences | Liverpool | United Kingdom |
Sponsors and Collaborators
- Liverpool John Moores University
Investigators
None specified.Study Documents (Full-Text)
None provided.More Information
Publications
None provided.- 18/SPS/014