Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12618000360213
Ethics application status
Approved
Date submitted
2/03/2018
Date registered
9/03/2018
Date last updated
17/07/2019
Date data sharing statement initially provided
17/07/2019
Type of registration
Prospectively registered

Titles & IDs
Public title
An almond, dried grape and dried cranberry (AGC) mix for improving endurance exercise performance in athletes
Scientific title
An almond, dried grape and dried cranberry (AGC) mix for improving endurance exercise performance in athletes
Secondary ID [1] 293274 0
None
Universal Trial Number (UTN)
U1111-1204-7575
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Cardiovascular fitness 305350 0
Aerobic fitness 306928 0
Condition category
Condition code
Cardiovascular 304633 304633 0 0
Normal development and function of the cardiovascular system
Musculoskeletal 306028 306028 0 0
Normal musculoskeletal and cartilage development and function

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Half of the participants will consume a mix almonds grapes and cranberries (daily intake of 75 grams of whole, raw, unsalted almonds, 25 grams of sultanas (dried grapes), 25 grams of dried cranberries), which are high in antioxidants, nitrates and arginine, while the other half of the participants will consume an amount of muesli bars that is of an equivalent energy intake. Both participant groups will consume their respective foods (almonds, sultanas and cranberries OR muesli bars) for 4 weeks. All foods will be provided to participants for free and participants may consume the foods in any portion size they desire (i.e. a single sitting or spread across the day) and their compliance will be assessed using a daily checklist, as well as any uneaten test foods being returned at testing visits.

Both groups will complete a five-week training program of standardised exercise training performed on participants own bikes that will be fitted with a stationary bike trainer, which essentially allows a road bike to function like an exercise bike in a gym. These training sessions will occur in participants' own homes and they will be required to exercise within specific, individualised heart rate zones (they will be provided and familiarised with heart monitors) for a prescribed duration. Participants will not be supervised during their training, but they will need to record their heart rate during training sessions and will also need to report the sessional rating of perceived exertion (RPE), which assesses how much effort was required for each session. During light training and tapering training, training compliance will be assessed by training impulse (which is a function of average heart rate and duration of exercise sessions) as recorded heart rate data can be analysed in Polar Pro Trainer 5 software. Due to the fatigue-induced changes in the function of the autonomic nervous system (including cardiovascular function), participants may have difficulty attaining the prescribed heart rate zones. Thus, during heavy training compliance will instead be determined by the function of sessional RPE and duration.

This training is split into three phases: a six-day period of light training, a 13-day period of heavy training, and a 13-day taper/recovery period. The initial six-days of light training will involve cycling for approximately 45 min per day, at a low/medium intensity, such that it will allow participants to recover from any pre-study training prior to the baseline assessments. Baseline testing is performed the day after completion of light training and then the dietary intervention (almonds, sultanas dried cranberries or control) begins and continues until the end of the study (i.e. for 4 weeks).

The day after baseline testing, participants complete 13 days of heavy training that is intended to induce substantial fatigue from which they will not recover by the testing session at the end of these 13 days (i.e. it is expected to reduce endurance performance). The heavy training program involves a strenuous, interval-style training schedule which requires participants to cycle for 124 min per day. Testing is again performed the day after completion of heavy training, with the 13-day tapering training phase then beginning the subsequent day. The taper training will involve cycling for approximately 50 min per day, at a medium intensity and includes 3 rest days. This will allow participants to recover from and adapt to the stimulus that was provided by the two weeks of heavy training, and is expected to increase performance to above baseline levels.

The rationale for this type of training program is to investigate whether almonds, sultanas and cranberries can reduce the impairment in exercise performance due to heavy physical training and/or induce a greater improvement in performance by the end of training, with both outcomes being advantageous for athletes.
Intervention code [1] 299563 0
Lifestyle
Intervention code [2] 300546 0
Treatment: Other
Comparator / control treatment
Half the participants will consume an isocaloric quantity of Golden Oats Baked Oaty Slice (i.e. eat an amount of Golden Oats Baked Oaty Slice that matches the energy intake of the mix of almonds, grapes and cranberries, without the associated intake of antioxidants, nitrates and arginine. Golden Oats Baked Oaty Slice is comprised of 47% wholegrain cereals, 17% butter, 13% golden syrup and 12% desiccated coconut, with the remaining ingredients reported in unspecified amounts. Both groups will be performing the same standardised training protocol.

The muesli bars will be provided to participants for free and and compliance will be assessed using a daily checklist, as well as any uneaten test foods being returned at testing visits.
Control group
Active

Outcomes
Primary outcome [1] 303885 0
Endurance exercise performance as assessed by five-minute cycling time-trial performance.
Timepoint [1] 303885 0
All timepoints (post-light training, post-heavy training and post-taper).
Primary timepoint is post-taper
Secondary outcome [1] 340361 0
Choice reaction time (at rest and during submaximal exercise) as assessed using the Deary-Liewald Reaction Time Task computer program.
Timepoint [1] 340361 0
All timepoints (post-light training, post-heavy training and post-taper)
Secondary outcome [2] 340362 0
Rate of heart rate increase (rHRI) at the onset of exercise, as assessed using a chest heart rate monitor.
Timepoint [2] 340362 0
All timepoints (post-light training, post-heavy training and post-taper)
Secondary outcome [3] 343632 0
Serum creatine kinase and lactate dehydrogenase as assessed from a serum assay.
Timepoint [3] 343632 0
All timepoints (post-light training, post-heavy training and post-taper)
Secondary outcome [4] 343633 0
Daily analyses of life demands for athletes (DALDA) responses
Timepoint [4] 343633 0
All timepoints (post-light training, post-heavy training and post-taper)
Secondary outcome [5] 343750 0
Diet quality as assessed by 3-day food diaries completed in the week prior to each testing visit, which will be analysed in Foodworks nutritional analysis software.
Timepoint [5] 343750 0
All timepoints (light training, heavy training and taper)
Secondary outcome [6] 343823 0
Exercise Economy as assessed by oxygen consumption via indirect calorimetry/gas analysis.
Timepoint [6] 343823 0
All timepoints (post-light training, post-heavy training and post-taper)
Secondary outcome [7] 344023 0
Urinary F2-Isoprostanes
Timepoint [7] 344023 0
All timepoints (post-light training, post-heavy training and post-taper)
Secondary outcome [8] 344024 0
Urinary nitrates
Timepoint [8] 344024 0
All timepoints (post-light training, post-heavy training and post-taper)
Secondary outcome [9] 344025 0
Urinary nitrites
Timepoint [9] 344025 0
All timepoints (post-light training, post-heavy training and post-taper)
Secondary outcome [10] 344026 0
Plasma F2-Isoprostanes
Timepoint [10] 344026 0
All timepoints (post-light training, post-heavy training and post-taper)
Secondary outcome [11] 344027 0
Plasma nitrates
Timepoint [11] 344027 0
All timepoints (post-light training, post-heavy training and post-taper)
Secondary outcome [12] 344028 0
Plasma nitrites
Timepoint [12] 344028 0
All timepoints (post-light training, post-heavy training and post-taper)

Eligibility
Key inclusion criteria
Male and aged 18-60 years.
*Non-smoker (minimum 6 months).
*Competitive standard cyclist or triathlete (minimum 6 months training at least 3 times per week)
*Have not consumed greater than 30 g/day of nuts or nut products (e.g. butter, meal, oil etc.) during the four weeks prior to familiarisation.
*Have not consumed greater than 50 g/day of grapes and/or sultanas or grape juice (greater than 1 litre week) during the four weeks prior to familiarisation.
*Have not consumed greater than 50 g/day fresh or dried cranberries or greater than 1 litre/day of cranberry juice during the four weeks prior to familiarisation.
*No allergies to almonds, sultanas or cranberries
*Do not answer yes to any question on page 1 of the Exercise and Sport Science Australia, Sports Medicine Australia and Fitness Australia Adult Pre-Exercise Health Screening Tool.
Minimum age
18 Years
Maximum age
60 Years
Sex
Males
Can healthy volunteers participate?
Yes
Key exclusion criteria
Participants will be excluded from the study if they meet any of the following criteria:
*Have a cardiovascular or metabolic condition that imposes a health risk during exercise.
*Have a gastrointestinal disorder that effects nutrient absorption.
*Regularly use any medication or supplements that may alter heart rate (HR) or exercise performance
*Regularly use anti-inflammatory drugs.
*Are unable to chew hard foods such as nuts.
*Take vitamin, mineral, herbal supplementation or medications that may have an impact on study outcomes.
*Are already involved in another research project within 30 days of commencement of the present study that in the opinion of the investigators may influence the outcomes for this study.
*Are unwilling to provide urine samples or have blood withdrawn via venepuncture.
*Show unwillingness to be randomised to either experimental group.
*Failure to satisfy the investigator regarding suitability to participate for any other reason.
*Are unwilling or unable to provide written consent.

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Central randomisation by computer
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
The first participant will be allocated to the control or AGC group via coin flip. Subsequent participants will be randomised to the (almond, dried grape and cranberry) AGC or control intervention by minimisation (Altman & Bland 2005) based on their age, BMI and endurance exercise (time-trial) performance to ensure the treatment groups are matched at baseline on these characteristics.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?


The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
In two recent studies conducted in our laboratory which evaluated the effects of a similar heavy training period followed by a taper on 5TT performance, the average work done at the end of the taper was 107.7 kJ with a pooled standard deviation of 9.84 kJ (Bellenger et al. 2016; 2017). Yi et al (2014) reported a 5.3% greater time-trial performance (effect size of 0.58) compared with placebo following four weeks of consuming 75 g/day of almonds. Thus, demonstrating a similar magnitude of increase in 5TT performance in the present study as being statistically significant in a two-tailed test with 80% power and at an a-level of 0.05 would require 96 participants to complete the study (48 AGC mix, 48 comparator foods). One hundred and eight participants will be recruited to account for a drop-out of ~10%. This is a conservative power analysis given that, in addition to using the same dose of almonds used by Yi et al (2014), in the present study participants will also consume dried grapes and cranberries, which may potentially induce a greater effect on performance.

Data will be presented as mean ± standard deviation (SD) for descriptive statistics and as means ± standard error (SEM) for reporting estimated effects. Statistical analysis will be performed using Stata/IC 15.1 (StataCorp, 2017). The effects of AGC and comparator foods on the dependent measures over time will be analysed using linear mixed effects models, with fixed effects entered as outcome measures, treatment allocation, and timepoint, and participant ID entered as a random effect. All covariances in the covariance matrix will be set to zero. Covariates will include age, training compliance, and dietary intervention compliance. If participants drop out, their available data will be used in the analysis provided the data due to drop-out are missing at random. The random effects mixed model will use all remaining available data in the analysis, and this will constitute an intention to treat analysis. A sensitivity analysis will then be performed using only data from participants who completed all aspects of the protocol (i.e. no missing data). If data is normally distributed, relationships will be assessed using Pearson’s correlation coefficient. If data is not normally distributed, it will be log transformed and analysed using non-parametric analyses. Repeated measures analyses will be used to evaluate relationships between different parameters. Statistical significance will be set at an alpha level of 0.05.

Recruitment
Recruitment status
Recruiting
Date of first participant enrolment
Anticipated
14/03/2018
Actual
9/04/2018
Date of last participant enrolment
Anticipated
21/10/2019
Actual
Date of last data collection
Anticipated
30/04/2020
Actual
Sample size
Target
108
Accrual to date
74
Final
Recruitment in Australia
Recruitment state(s)
SA

Funding & Sponsors
Funding source category [1] 297902 0
Charities/Societies/Foundations
Name [1] 297902 0
International Nut and Dried Fruit Council Foundation.
Country [1] 297902 0
Spain
Primary sponsor type
Individual
Name
Professor Jon Buckley
Address
University of South Australia, School of Health Science; Alliance for Research in Exercise, Nutrition and Activity
108 North Terrace, Adelaide, South Australia, 5000
Country
Australia
Secondary sponsor category [1] 297983 0
Individual
Name [1] 297983 0
Professor Kevin Croft
Address [1] 297983 0
University of Western Australia
35 Stirling Hwy, Crawley WA, 6009
Country [1] 297983 0
Australia
Secondary sponsor category [2] 298735 0
Individual
Name [2] 298735 0
Associate Professor Alison Coates
Address [2] 298735 0
University of South Australia, School of Health Science; Alliance for Research in Exercise, Nutrition and Activity
108 North Terrace, Adelaide, South Australia, 5000
Country [2] 298735 0
Australia
Secondary sponsor category [3] 298736 0
Individual
Name [3] 298736 0
Dr Alison Hill
Address [3] 298736 0
University of South Australia, School of Pharmacy and Medical Sciences; Alliance for Research in Exercise, Nutrition and Activity
108 North Terrace, Adelaide, South Australia, 5000
Country [3] 298736 0
Australia
Secondary sponsor category [4] 298737 0
Individual
Name [4] 298737 0
Dr Max Nelson
Address [4] 298737 0
University of South Australia, School of Health Science; Alliance for Research in Exercise, Nutrition and Activity
108 North Terrace, Adelaide, South Australia, 5000
Country [4] 298737 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 298952 0
University of South Australia Human Research Ethics Committee
Ethics committee address [1] 298952 0
14-38 St Bernards Rd, Magill SA 5072
Ethics committee country [1] 298952 0
Australia
Date submitted for ethics approval [1] 298952 0
02/02/2018
Approval date [1] 298952 0
08/02/2018
Ethics approval number [1] 298952 0
200372

Summary
Brief summary
The main aim of this study is to assess whether consuming a mix of almonds, dried grapes and dried cranberries daily for four weeks can improve recovery from fatigue and exercise performance compared with a control snack. The secondary aims are to investigate the relationship between consumption of these foods and blood and urinary markers of training-induced stress/damage and choice reaction time at rest and during exercise. Additionally, this study aims to evaluate the whether changes in heart rate can be used to predict changes in endurance exercise performance.

Almonds are a rich source of arginine and antioxidants, while grapes and cranberries are also rich sources of antioxidants and nitrates. Studies have shown that dietary antioxidants improve endurance exercise performance by reducing exercise-induced damage to muscle. In addition, an increased dietary intake of arginine, nitrates and nitrites has been shown to improve endurance exercise performance in recreational athletes due to increases in blood flow to muscles. Thus, combining almonds, which are a good source of antioxidants and arginine, with grapes and cranberries, which are good sources of antioxidants and nitrates, may reduce exercise-induced damage to contracting muscle and promote increased muscle and brain blood flow. This in turn might reduce fatigue and promote improvements in endurance exercise performance.

The period of heavy training is designed to produce negative changes in all of the outcomes discussed above, thus it is desirable for AGC to reduce the magnitude of these negative changes, in addition to resulting in superior changes in the outcomes following the taper training, when measures should be at their peak values.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 78766 0
Prof Jon Buckley
Address 78766 0
University of South Australia, City East campus, 108 North Terrace, Adelaide, SA 5001
Country 78766 0
Australia
Phone 78766 0
+61 8 830 21853
Fax 78766 0
Email 78766 0
[email protected]
Contact person for public queries
Name 78767 0
Prof Jon Buckley
Address 78767 0
University of South Australia, City East campus, 108 North Terrace, Adelaide, SA 5001
Country 78767 0
Australia
Phone 78767 0
+61 8 830 21853
Fax 78767 0
Email 78767 0
[email protected]
Contact person for scientific queries
Name 78768 0
Prof Jon Buckley
Address 78768 0
University of South Australia, City East campus, 108 North Terrace, Adelaide, SA 5001
Country 78768 0
Australia
Phone 78768 0
+61 8 830 21853
Fax 78768 0
Email 78768 0
[email protected]

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
IPD will not be made public as the study is not publicly funded. The study was funded privately through industry and the IPD remains the intellectual property of the industry partner.


What supporting documents are/will be available?

Doc. No.TypeCitationLinkEmailOther DetailsAttachment
2392Study protocold’Unienville, NMA, Hill, AM, Coates, AM, Yandell C, Nelson, MJ & Buckley, JD 2019 'The effects of almond, dried grape and dried cranberry consumption on endurance exercise performance, recovery and psychomotor speed: protocol of a randomised controlled trial', BMJ Open Sport and Exercise Medicine, Under Review  



Results publications and other study-related documents

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