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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Prospectively registered

Titles & IDs
Public title
Effect of blackcurrant consumption on physical fitness, bioenergetics and natural immunity during high intensity training; involvement of mitochondrial adaptation?
Scientific title
A crossover study examining blackcurrant consumption on physical fitness, immunity and mitochondrial adaptation during high intensity training in healthy subjects.
Secondary ID [1] 283650 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Fitness adaptation and natural immunity
290597 0
Fitness adaptation, bioenergetics and mitochondria number/mass, function and fagility. 290598 0
Condition category
Condition code
Inflammatory and Immune System 290984 290984 0 0
Normal development and function of the immune system

Study type
Description of intervention(s) / exposure
Study design- The study is divided into 2 stages, the first stage will establish a high intensity training (HIT) protocol together with appropriate biological measurements (listed below). The second stage will apply the HIT protocol to assess the additional fitness & health benefits of a consuming a blackcurrant extract prior to each HIT session.
Stage 1. This first stage of the study will establish a HIT protocol that will identify adaptive changes in fitness and health (focus on mitochondrial bioenergenesis and natural immunity). These changes will be assessed by physical, subjective and blood biochemical parameters.
Study participants - Participants will be assessed for their suitability by assessing their ability to do a short-cycle (5 km) with breathing apparatus on a stationary Wingate bike and a habitual Baecke questionnaire. During the trial, participants will be asked to complete on-line health and diet diaries each week (monitored by the trial co-ordinator) and asked to omit foods and dietary supplements that are high in antioxidants for the duration of the study (a list will given to all participants) .
Fitness assessments – (i) VO2 max. A stationary Wingate cycle ergometer will be used to assess participant’s VO2 max. This will require the participant to cycle at incrementally wattage until volitional fatigue. The rate of CO2 increase, heart rate and respiratory exchange ratio (ratio of CO2 exhaled vs. O2 inhaled) will also be measured. In addition, blood lactate will be measured immediately post exercise. (ii) 15K stationary cycle ergometer time-trial. Participants will initally be asked to donate blood (see listof tests below) and complete physiological (e.g. heart rate, O2/CO2 exchange, thigh /tenderness measurements) and subjective (VAS fatigue/pain) assessments. Subjects will then be asked to perform a 15K timed trial on a stationary Wingate bike as quickly as possible. The completion time plus heart rate, work output, O2/CO2 exchange will be assessed. Immediately post cycle, physiological and subjective evaluations will be repeated. The physiological parameters will then be continuously monitored over the first 10 mins of exercise recovery, followed by a final measurement taken 20 mins post exercise. Additional blood samples will be taken immediately post exercise and after 20 mins recovery. Blood collected during this fitness assessment will be analyzed for blood glucose & lactate, insulin, inflammatory markers (C-reactive protein, IL-6, IL-10) levels, as well as oxidative and antioxidant parameters. In addition, blood leukocyte and platelet mitochondria function (e.g. respirometry, pro- & anti-oxidant capacity, fragility) will be assessed.
HIT protocol - This will be performed over a 2-week period using a stationary Wingate cycle ergometer. The HIT protocol consists of a total of 6 HIT sessions over a 2-week period; 3 sessions every week. Participants will complete a 5 min warm-up cycle at 50W immediately prior to each HIT. The HIT protocol will consist of a repeated bout of 30 sec all-out cycling on a Wingate ergometer set at a resistance corresponding to 4.0% of the subject's body mass. Each bout will be separated by 1 min active recovery (light cycle at 30W). Incremental training will be implemented by increasing the number of repetitions from 6 repeats during first 2 sessions, to eight repeats during sessions 3 and 4 and then ten repeats during sessions 5 and 6. Within each HIT session, we aim to assess (i) leg swelling (thigh diameter & tenderness and (ii) VAS (fatigue, pain/soreness) and RPE evaluation.
Stage 2: The fitness assessment, HIT and biological parameters established in stage 1 will be applied. The trial is designed as a double-blind cross-over involving two 2-week HIT blocks sandwiched between the two fitness assessments (VO2max and a 15K cycle ergometer time-trial) at the beginning and end of each 2-week HIT block. The dietary intervention will be taken prior to each of the HIT session (see above for details)
Dietary Intervention - Participants will consume 3.2mg/Kg (anthocyanin equivalent) of a commercially-available anthocyanin-rich 30% blackcurrant extract (Just-The-Berries, NZ) OR a placebo (equivalent sugar and vitamin C present in the blackcurrant extract). Following a 2-week wash-out period, trial subjects will then cross-over the dietary interventions. The blackcurrant extract contains only blackcurrant and consists of 89% anthocyanin and 11% non-anthocyanin polyphenols). The blackcurrant extract will given to participants within opague gelatin capsules. Furthermore, neither the trial subjects nor the trial co-ordinator will know the order or the treatment being given in each arm of the study.
Intervention code [1] 288351 0
Other interventions
Comparator / control treatment
Opague gelatin capsules containing equivalent sugar and vitamin C present within the blackcurrant extract.
Control group

Primary outcome [1] 290970 0
Changes in fitness, biogenerensis and immunity before and after HIT training.
(1) Exercise (physical and subject) parameters: VO2max L/min, O2/CO2 exchange, Heart rate, Work output, Lactate threshold, rating of perceived exertion (RPE), Fatigue, pain/soreness VAS & thigh swelling.
(2) Innate immunity. Circulating inflammatory markers (IL-6, IL-10, C-reactive protein), leukocyte immune responsiveness to bacterial (TLR4 /TL2 ligands) and viral (TLR7 ligands) antigens (ex vivo studies)
(3) Mitochondrial number, function (respirometry)and fagility status in circulating leukocytes and platelets.
Timepoint [1] 290970 0
The above assessment will be taken as part of the 15K cycle time-trial fitness assessment. Measruements will be be made before and immediately after the completion of the 15Km time trial and then after 20 mins recovery.
Secondary outcome [1] 305707 0
Changes in blood biochemistry (as indicators of change in general health and well-being). Antioxidant (FRAP, SOD, catalase, GPx), oxidative stress parameters (carbonyls, MDA) and insulin and free fatty acid profiles.
Timepoint [1] 305707 0
The above assessment will be taken as part of the 15K cycle time-trial fitness assessment. Measruements will be be made before and immediately after the completion of the time trial and then after 20 mins recovery.

Key inclusion criteria
Healthy persons of either gender
Minimum age
18 Years
Maximum age
60 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Participants in this study will be excluded if they have any of the following conditions: (i) blood borne diseases, e.g. hepatitis; (ii) clinically diagnosed high/low blood pressure; (iii) pregnant, or planning to get pregnant; (iv) recent bacterial or viral illness or vaccinations; (v) chronic illness that affects their immune system (e.g. lupus) or (vi) any medication that affects the properties of blood, e.g. clotting.
In addition subjects recruited for this study will be excluded if they have (i) any health conditions that affect their ability to perform the exercise regime required in this study (i.e. heart and/or breathing problems, hernia or injury) or (ii) intolerance, hypersensitivity or allergy to foods, especially fruit.

Study design
Purpose of the study
Educational / counselling / training
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Allocation is concealed. Allocation is assigned by a single fellow scientist who is not associated with the work. No participants or trial scientists undertaking the work are aware of the allocation. Allocation is held concealed until completion of the trial and analysis of the data is finalized.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomization using a spreadsheet random function
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s
The people administering the treatment/s
The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
Statistical analysis of data.
All trial data will be captured on study specific visit worksheets (except for online surveys) and transcribed to an access database, held at Plant and Food Research. Data will be expressed as mean +/- standard error of the mean.
(a) Exercise trial data analysis. Previous studies have shown that a sample size of 10 has a desired statistical power level of 0.8 with a probability level of 0.05. This is calculated on an anticipated effect size (Cohens’s d) of 1.159 based on paired SD for a difference in VO2 Max L/min. In this study, data will be analyzed using Statistical Analysis Software (SAS) 9.1 for Windows (version 5.1.2600). Using a repeated measures analysis of variance (ANOVA), comparison between conditions over time for each measure (independent variable) will also be determined, providing levels of significance for trial effect, treatment effect, and interaction effect between treatment and trial. A post-hoc tests will also be performed to identify significant differences at each time point. Values will be presented as means +/- standard deviation (or standard error) at a 95% significance level (P equal to 0.05). Pearson’s Product Moment Correlation Coefficient’s may also be assessed using SPSS 15.0 for Windows to investigate if there are any relationships between certain variables by giving an R-value between 0.0 and 1.00 (or -0.0 and -1.00).

(b) Ex vivo cell experiment data analysis. Statistical significance for the comparison between two groups will be assessed using a paired Student's t-test. Multiple comparisons were assessed by a two-way ANOVA. Where appropriate, the original data will be transformed to achieve normality and constant variance in the residuals. Statistical significance for all indices was set at P less than or equal to 0.05 with a confidence level of 95%.

Recruitment status
Not yet recruiting
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment outside Australia
Country [1] 5674 0
New Zealand
State/province [1] 5674 0
Hamilton, Waikato, New Zealand

Funding & Sponsors
Funding source category [1] 288420 0
Government body
Name [1] 288420 0
The New Zealand Institute of Plant and Food Research
Address [1] 288420 0
Private Bag 92169 Auckland 1142
New Zealand
Country [1] 288420 0
New Zealand
Primary sponsor type
Government body
The New Zealand Institute of Plant and Food Research
Private Bag 92169 Auckland 1142
New Zealand
New Zealand
Secondary sponsor category [1] 287126 0
Name [1] 287126 0
Address [1] 287126 0
Country [1] 287126 0

Ethics approval
Ethics application status
Ethics committee name [1] 290296 0
The Central Health and Disability Ethics Committee
Ethics committee address [1] 290296 0
1 The Terrace C/- MEDSAFE, Level 6, Deloitte House 10 Brandon Street PO Box 5013 Wellington 6011
Ethics committee country [1] 290296 0
New Zealand
Date submitted for ethics approval [1] 290296 0
Approval date [1] 290296 0
Ethics approval number [1] 290296 0

Brief summary
Eating fruit as part of a daily diet is essential in the maintenance of health and well-being. Recent studies show that in addition to containing antioxidants, certain fruit contain other compounds that boost our body's defenses. Similarly, regular exercise has been shown to improve fitness and wellbeing. In this study we identify fruits that if eaten prior to exercise will facilitate the health benefits of regular exercise. The study is divided into 2 stages. Stage 1, will establish a high intensity exercise that if performed 3 days a week for 2-weeks will show an improvement in fitness and the body's defenses. In stage 2, this training strategy will be applied to determine whether eating blackcurrants before each exercise bout will improve the health effects observed from exercising alone. In stages 2 and 3, the participant will be asked to complete 2 fitness assessments on a cycle ergometer; VO2 max and a time trial over 15 Km; during these assessments the subjects breathing (O2/CO2 exchange) and heart rate will be monitor. Blood will also be taken to assess mitochondrial bioenergetics and natural immunity. The participation time required for stage 1 will be 24 days, whereas for stage 2, it will be 60 days due to the cross-over design of the study.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 44530 0
Dr Suzanne Hurst
Address 44530 0
NZ Institute for Plant and Food Research
Food Industry Science Centre
Batchelar Road
Palmerston North 4472
New Zealand

Country 44530 0
New Zealand
Phone 44530 0
+64 6 355 6231
Fax 44530 0
+64 6 351 7050
Email 44530 0
Contact person for public queries
Name 44531 0
Ms Kirsty Lyall
Address 44531 0
NZ Institute for Plant and Food Research
Ruakura Research Centre
Bisley Rd
Hamilton 3214
New Zealand
Country 44531 0
New Zealand
Phone 44531 0
Fax 44531 0
64 79594431
Email 44531 0
Contact person for scientific queries
Name 44532 0
Dr Suzanne Hurst
Address 44532 0
NZ Institute for Plant and Food Research
Food Industry Science Centre
Batchelar Road
Palmerston North 4472
New Zealand
Country 44532 0
New Zealand
Phone 44532 0
+64 6 355 6231
Fax 44532 0
+64 6 351 7050
Email 44532 0

No information has been provided regarding IPD availability
Summary results
No Results