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Trial registered on ANZCTR


Registration number
ACTRN12617000041358
Ethics application status
Approved
Date submitted
4/01/2017
Date registered
10/01/2017
Date last updated
10/01/2017
Type of registration
Retrospectively registered

Titles & IDs
Public title
The effects of d-aspartic acid supplementation in resistance-trained men over a three month training period: A randomised controlled trial.
Scientific title
D-aspartic acid supplementation in resistance-trained men over a three month training period and its effects on hormones, neural adaptation and training outcomes.
Secondary ID [1] 290837 0
None
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Healthy resistance-trained men 301513 0
Condition category
Condition code
Alternative and Complementary Medicine 301227 301227 0 0
Other alternative and complementary medicine
Musculoskeletal 301239 301239 0 0
Normal musculoskeletal and cartilage development and function

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Supplement study with a randomised, double-blinded, and placebo-controlled research design.

Supplement: D-aspartic acid.
Dose: 6 grams per day.
Duration: Administered every day for 12 weeks.
Mode: Oral administration by opaque pill capsules.

Adherence to daily supplementation was controlled for via check-ups and prompts at supervised training sessions.

Participants trained four days per week, with supervised sessions conducted a minimum of once per week, with additional monitoring of adherence conducted via training logs. Supervised resistance training sessions were conducted by a trained exercise physiologist at the University laboratory gym. The training sessions that the participants could not make at the University gym were conducted at the gym the participant normally exercised at.

Both groups (DAA and Placebo) began training after baseline testing and continued for 12 weeks. The prescribed training involved five exercises that included 3-5 sets of various repetition maximum (RM) prescriptions (2RM – 10RM). Prescription of intensity was as close to failure on the last repetition, thus training intensity ranged approximately from 70% to 95% of the participant's one repetition maximum. A primary lift was prescribed for each day – deadlift, bench press, good morning/stiff-leg deadlift and squat, with accessory exercises for balance and volume. Types of equipment for the exercises included barbell, machine, dumbell and bodyweight. Each training session lasted for approximately 1-1.5 hours.

There was no direct personalisation of the training program with respect to exercises and relative prescription, however, as the prescription was based on repetition maximums the absolute loads lifted and training volume was personalised session by session according to the RM target. If a participant found they could perform more or less than the load for an exercise the load was increased or decreased the following session to keep them with the repetition range target. All participants performed the same exercises, and no other personalisation of the training program was implemented.
Intervention code [1] 296761 0
Treatment: Other
Comparator / control treatment
An equal-weight, visually-matched placebo (rice flour) was administered to the placebo group. Both Placebo and the d-aspartic acid groups were exposed to the same training program.
Control group
Placebo

Outcomes
Primary outcome [1] 300637 0
Total testosterone, via electrochemiluminescence immunoassay, on a Roche E170 system.
Timepoint [1] 300637 0
Baseline, and at 6 and 12 weeks after intervention commencement.
Primary outcome [2] 300638 0
Free testosterone, calculated from total testosterone, sex-hormone-binding globulin and albumin using the Vermeulen equation.
Timepoint [2] 300638 0
Baseline, and at 6 and 12 weeks after intervention commencement.
Secondary outcome [1] 330467 0
Estradiol, via chemiluminescent microparticle immunoassay, on an Abbott i2000.
Timepoint [1] 330467 0
Baseline, and at 6 and 12 weeks after intervention commencement.
Secondary outcome [2] 330468 0
Sex-hormone-binding globulin, via electrochemiluminescence immunoassay, on a Roche E170 system.
Timepoint [2] 330468 0
Baseline, and at 6 and 12 weeks after intervention commencement.
Secondary outcome [3] 330469 0
Albumin, via bromocresol green succinate buffer method (BCG), on an Abbott ARCHITECT c16000.
Timepoint [3] 330469 0
Baseline, and at 6 and 12 weeks after intervention commencement.
Secondary outcome [4] 330470 0
Calf muscle thickness, using B-mode ultrasound imaging on an Echo Blaster 128 family scanner and Echo Wave II v2.3.6 software.
Timepoint [4] 330470 0
Baseline, and at 6 and 12 weeks after intervention commencement.
Secondary outcome [5] 330471 0
Quadriceps muscle thickness, using B-mode ultrasound imaging on an Echo Blaster 128 family scanner and Echo Wave II v2.3.6 software.
Timepoint [5] 330471 0
Baseline, and at 6 and 12 weeks after intervention commencement.
Secondary outcome [6] 330472 0
Quadriceps muscle cross-sectional area, using B-mode ultrasound imaging with the extended-field-of-view methodology on an Echo Blaster 128 family scanner and Echo Wave II v2.3.6 software.
Timepoint [6] 330472 0
Baseline, and at 6 and 12 weeks after intervention commencement.
Secondary outcome [7] 330475 0
Evoked V-waves in the calf muscles (neural change) using a 1 ms square wave pulse, delivered by a constant current stimulator (DS7AH).
Timepoint [7] 330475 0
Baseline, and at 6 and 12 weeks after intervention commencement.
Secondary outcome [8] 330476 0
Evoked H-waves in the calf muscles (neural change) using a 1 ms square wave pulse, delivered by a constant current stimulator (DS7AH).
Timepoint [8] 330476 0
Baseline, and at 6 and 12 weeks after intervention commencement.
Secondary outcome [9] 330477 0
Maximal Isometric force of the leg extensors using an isokinetic dynamometer - KinCom 125, version 5.32.
Timepoint [9] 330477 0
Baseline, and at 6 and 12 weeks after intervention commencement.
Secondary outcome [10] 330478 0
Maximal Isometric force of the plantar flexors using an isokinetic dynamometer - KinCom 125, version 5.32.
Timepoint [10] 330478 0
Baseline, and at 6 and 12 weeks after intervention commencement.

Eligibility
Key inclusion criteria
Participants must have been performing regular resistance training exercise for at least three days per week for the previous two years
Participants must have the ability to bench press 100% of their bodyweight
Minimum age
18 Years
Maximum age
36 Years
Gender
Males
Can healthy volunteers participate?
Yes
Key exclusion criteria
Participants with acute medical conditions were excluded.
Participants with chronic medical conditions were excluded.
Participants currently taking any ergogenic or testosterone boosting supplements were excluded.

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)
Group allocation was managed by a technical officer, while the primary investigator and participants was kept blind to group assignment throughout the experimental intervention, and data analysis.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Participants were randomly allocated to treatment groups following a block randomisation procedure (block size of four) based on a computer-generated list of random numbers.
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
Parallel
Other design features
Phase
Type of endpoint(s)
Statistical methods / analysis

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
NSW
Recruitment postcode(s) [1] 14966 0
2560 - Campbelltown

Funding & Sponsors
Funding source category [1] 295266 0
University
Name [1] 295266 0
Western Sydney University, HDR Candidate Support Funding.
Address [1] 295266 0
Sport and Exercise Science
School of Science and Health, Campbelltown Campus
Western Sydney University,
Narellan Road, Campbelltown NSW 2560 Australia
Country [1] 295266 0
Australia
Primary sponsor type
University
Name
Western Sydney University
Address
Sport and Exercise Science
School of Science and Health, Campbelltown Campus
Western Sydney University,
Narellan Road, Campbelltown NSW 2560 Australia
Country
Australia
Secondary sponsor category [1] 294092 0
None
Name [1] 294092 0
Address [1] 294092 0
Country [1] 294092 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 296600 0
University of Western Sydney Human Research Ethics Committee (EC00314)
Ethics committee address [1] 296600 0
Human Ethics Officer
Research Engagement, Development and Innovation (REDI)
Western Sydney University
Locked Bag 1797
Penrith NSW 2751
Ethics committee country [1] 296600 0
Australia
Date submitted for ethics approval [1] 296600 0
04/03/2013
Approval date [1] 296600 0
28/03/2013
Ethics approval number [1] 296600 0
H10087

Summary
Brief summary
Recent research has shown that resistance-trained men who supplemented with 6 g.d-1 of d-aspartic acid (DAA) over 14 days significantly reduced total testosterone and free testosterone levels. The long-term training consequences of reduced testosterone from DAA supplementation are currently unknown. The primary objective of this study was to evaluate the effectiveness of DAA to increase basal testosterone levels over three months of resistance training. A secondary objective was to establish potential mechanisms for changes in strength and hypertrophy. Based on our previous findings, it was hypothesised that the DAA group would experience decreased total testosterone and free testosterone. In addition, it was hypothesised that the DAA group would experience increased strength, explained by improved neural plasticity.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 71438 0
Mr Geoffrey Melville
Address 71438 0
Building 20, Room 23, Campbelltown Campus
University of Western Sydney
Locked Bag 1797
Penrith NSW 2751
Country 71438 0
Australia
Phone 71438 0
+61246203917
Fax 71438 0
+61246203020
Email 71438 0
g.melville@hotmail.com
Contact person for public queries
Name 71439 0
Mr Geoffrey Melville
Address 71439 0
Building 20, Room 23, Campbelltown Campus
University of Western Sydney
Locked Bag 1797
Penrith NSW 2751
Country 71439 0
Australia
Phone 71439 0
+61246203917
Fax 71439 0
+61246203020
Email 71439 0
g.melville@hotmail.com
Contact person for scientific queries
Name 71440 0
Mr Geoffrey Melville
Address 71440 0
Building 20, Room 23, Campbelltown Campus
University of Western Sydney
Locked Bag 1797
Penrith NSW 2751
Country 71440 0
Australia
Phone 71440 0
+61246203917
Fax 71440 0
+61246203020
Email 71440 0
g.melville@hotmail.com

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary