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NCT Number: NCT04370353

Impact of Cocoa Flavanols on Pulmonary Oxygen Uptake Kinetics and Exercise Tolerance in Sedentary Middle-aged Adults

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.

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Key information

Conditions

Aging Behavior Sedentary Behavior

Age range

35 year–55 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Research Institute for Sport & Exercise Sciences

Liverpool, United Kingdom

Who can participate

Healthy volunteers accepted: Yes

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

Inclusion criteria

  • Aged 35-55 years
  • Healthy (no known cardiovascular or metabolic disorders e.g. diabetes)
  • 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

  • Smokers
  • Medical history of cardiovascular and/or metabolic disease, including diabetes and abnormal blood pressure
  • Family history of cardiovascular disease
  • Currently taking any medication
  • Asthmatic
  • Currently suffering from musculoskeletal injury
  • Younger than 35 or older than 55 years old
  • Known food allergies or special dietary requirements
  • Currently taking any dietary supplements
  • Currently engaging in >2 hours structured training per week

Treatment and study plan

Cocoa flavanols

Dietary Supplement

Flavonoid-rich cocoa powder, containing 100mg total flavanols per 316mg.

Placebo supplement

Dietary Supplement

Microcrystalline filler, containing 0mg total flavanols.

Primary outcomes

  1. Oxygen uptake kinetics

    Time frame: 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.

  2. Exercise tolerance

    Time frame: 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 outcomes

  1. Heart rate

    Time frame: 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.

  2. Blood pressure

    Time frame: 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

  3. Blood lactate

    Time frame: 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

  4. Physical activity and sedentary behaviour

    Time frame: 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.

  5. Perceived workload

    Time frame: 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.

Sponsors and collaborators

Lead sponsor

Liverpool John Moores University

Other

Registry information

Official study title

Investigating the Impact of Cocoa Flavanol Supplementation on Pulmonary Oxygen Uptake Kinetics and Exercise Tolerance in Sedentary Middle-aged Adults

Important dates

Study start
2018
Primary completion
2019
Study completion
2019
First posted
Apr 30, 2020
Registry last updated
Apr 30, 2020

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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