None listed
Conditions
Brief summary
The mechanisms underlying performance increases following anthocyanin supplementation have not been elucidated. However, a review examining dietary anthocyanin intake postulates that performance improvements may be mediated by increases in endothelial nitric oxide and subsequent enhanced muscle blood flow (Cook & Williams, 2019). In addition, the same review highlighted that most studies reporting performance benefits utilised a chronic BE loading regime but also provided an acute dose immediately before exercise, therefore raising the question if any performance benefits were due to the intake of the final acute dose, or a result of chronic loading. Due to the lack of research examining the effects of acute versus chronic BE supplementation on exercise performance the primary aim of this research was to examine the effects of a single acute dose of blackcurrant extract (BE) on exercise performance compared to 7-day supplementation. A secondary aim is to determine if any respiratory benefits exist with supplementation, and finally if BE supplementation (acute or chronic) in healthy exercising individuals improves respiratory function. The proposed dose of blackcurrant extract is 4.3 mg/kilogram body weight. Subjects will take an acute dose of either placebo or BE 60 minutes before completing an incremental cycling test to exhaustion, followed by 15 minutes rest, and then complete a 4 km time trial. BE and PL will be administered in purple, berry flavoured gelatin capsules. Following the acute trial, subjects will supplement for 7-days and return to the lab to complete the testing again. A 7-day washout will occur before completing the protocols again but consuming the alternative supplement. Two familiarisation trials will be completed to calculate the coefficient of variation (CV ) of the exercise protocol and for subjects to become accustomed to the protocols and testing, thereby reducing any potential learning effects. There will be no supplementation at the familiarisation trials.
Interventions
Subjects will consume blackcurrant extract (BE) powder administered in opaque, purple, berry flavoured gelatin capsules at a dose of 4.3 mg/kg body weight. Supplementation will be 60 minutes before exercise for the acute trial and for 7 days (one dose per day taken orally in gelatin capsules) before the next exercise trial. The number of placebo capsules will match the quantity needed to administer a 4.3 mg/kg body weight dose of BE. Subjects will be oversupplied with capsules and a countback wi
Subjects will consume blackcurrant extract (BE) powder administered in opaque, purple, berry flavoured gelatin capsules at a dose of 4.3 mg/kg body weight. Supplementation will be 60 minutes before exercise for the acute trial and for 7 days (one dose per day taken orally in gelatin capsules) before the next exercise trial. The number of placebo capsules will match the quantity needed to administer a 4.3 mg/kg body weight dose of BE. Subjects will be oversupplied with capsules and a countback will be done to ensure supplementation adherence. The exercise protocol is an incremental V'O2 max test of 3 minute stages increasing 30 watts every 3 minutes until exhaustion and/or an inability to maintain a cycling cadence of > 75 rpm. Following the completion of the incremental test, subjects will have a 15 minute rest, and then be required to complete a maximal 4 km time trial as fast as possible. All cycling tests will be performed on a calibrated cycle ergometer. Subjects will then repeat the trial after consuming an acute dose of the alternative supplement (BC/PL) and then consume a daily dose for a period of 7 days before completing the exercise protocol again. There is a 7-day washout period between chronic and acute supplementation trials.
Sponsors
University of Auckland
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Treatment
Masking
Blinded (masking used) (Subject, Caregiver, Outcomes Assessor)
Eligibility
Sex/Gender
All
Age
16 Years to 55 Years
Healthy volunteers
Yes
Inclusion criteria
Trained male and female cyclists with a training history of > 2 years, No chronic health conditions or respiratory conditions (i.e. asthma or exercise-induced asthma or breathlessness), no acute respiratory illness within the last month, no medications that affect respiratory, cardiovascular or immune function, and over 16 years of age
Exclusion criteria
None
Outcome results
None listed