Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12622001477718
Ethics application status
Approved
Date submitted
3/11/2022
Date registered
23/11/2022
Date last updated
23/11/2022
Date data sharing statement initially provided
23/11/2022
Date results provided
23/11/2022
Type of registration
Retrospectively registered

Titles & IDs
Public title
Exercise training in older men and the effect on brain derived neurotrophic factor (BDNF).
Scientific title
Serum brain-derived neurotrophic factor (BDNF) and time-trial performance in older untrained men
Secondary ID [1] 308290 0
NIL
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Ageing 328072 0
Neuroplasticity 328073 0
Condition category
Condition code
Neurological 325133 325133 0 0
Studies of the normal brain and nervous system
Physical Medicine / Rehabilitation 325134 325134 0 0
Other physical medicine / rehabilitation

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Eight untrained healthy males aged 53–64 years performed a familiarisation session at the Exercise & Sports Science Laboratories located on the Bathurst campus. Each session was supervised by a qualified Exercise Scientist. The session included the cycling time trial which comprised a 30 s maximal effort sprint for every 4.5 min of lower intensity pace for a total of 25 min. Although the participants self-selected the gears and cadence throughout the entire 25 min, the actual time trial required them to cover as much distance as possible and be fully expended at the end of 25 min. Between 7-10 days following this, the participant returned to complete the initial self-paced time trial.

The exercise training intervention followed a mixed method of training over a 12 week period which commenced 7 days following the initial self-paced time trial. and was conducted in the University resistance training gym on the Bathurst campus. Each session was supervised by a qualified exercise scientist. The first session was aerobic, the second session was strength, and the third session was mixed aerobic and strength for a total of 3 sessions per week. At the third session, participants could start with either aerobic or strength training. Aerobic exercises were performed on the cycle ergometer, treadmill or rowing machine and progressed from 15–55 min over the 12 weeks. All bouts of aerobic exercise followed the time trial protocol of 30 s maximal effort sprint for every 4.5 min of lower intensity, and targeted an intensity of > 70% peak heart rate for the lower intensity sections and > 80% peak heart rate for the sprint sections. Resistance exercises targeting the major muscle groups were performed on pulley-weight machines (chest press, seated row, lat pulldown, shoulder press, leg press, leg curl, squats and lunges). Participants progressed from 2 sets of 3 exercises to 4 sets of 8 exercises over the 12 weeks. All sets were performed at loads permitting completion of 10 repetitions, with loads increasing when 12–15 repetitions were completed on the final set. At the first mixed session, 15 min of aerobic activity and 2 sets of 3 strength exercises were performed. At the final mixed session, 27 min aerobic activity and 2 sets of 8 strength exercises were performed. All exercise sessions were fully supervised by qualified personnel who checked compliance using session checklists completed after each session. Instruction and supervision for each session for each participant was provided by the Chief Investigator with the training program undertaken within the University Bathurst campus resistance training facility.

Between 3-7 days after completing the last training session, participants returned to the laboratory to complete a post training self paced cycling time trial for comparison of the pre-training trial.
Intervention code [1] 324743 0
Treatment: Other
Comparator / control treatment
Self paced cycling trial was completed before and after a 12-week aerobic and resistance training intervention. A series of measures evaluating skeletal muscle performance and serum brain derived neurotrophic factor was measured.
Control group
Active

Outcomes
Primary outcome [1] 332956 0
Changes in BDNF following 12 weeks of exercise training along with changes in performance.

This was assessed by a 4-ml blood sample collected via aseptic venipuncture at the same time of the day for each participant from the antecubital vein while resting in a seated position for the determination of resting serum BDNF levels pre- and post-training. Participants were not required to fast before each blood collection. The blood was allowed to clot for at least 30 min at room temperature and was then centrifuged (Heraeus™ Primo™ R, Thermo Fisher, Waltham, MA) for 10 min at 2200 relative centrifugal force at 20 °C. The supernatant was decanted and stored in a -80 °C freezer until assayed. Serum concentrations of BDNF were measured using a MILLIPLEX kit (Human Pituitary Bead Panel 2, EMD Millipore, Billerica, MA) according to the manufacturer’s instructions. Samples and BDNF standards were measured in duplicate and results reported in this study were obtained with a sample dilution of 1 part serum to 10 parts sample diluent. The 96-well plate was incubated overnight with agitation on a plate shaker (ThermoMixer® C, Eppendorf, Hamburg, Germany) at 700 rpm and 4 °C and the plate was run using MAGPIX® with xPONENT software (Luminex, Austin, TX). The sensitivity as reported in the MILLIPLEX kit literature was 2.45 pg/ml with an intraassay and interassay CV of <10 and <15%, respectively.
Timepoint [1] 332956 0
Post 12 week training intervention
Secondary outcome [1] 415329 0
Changes in self-paced exercise performance post 12 week exercise training was primarily assessed by power output derived from Velotron 3D software (Version 1.0, RacerMate Inc., Seattle, WA) normalised to lean leg mass and calculated as power output (W)/lean leg mass (kg). In addition, distance covered and heart rate will be measured to assess changes.
Timepoint [1] 415329 0
Post 12 week-exercise training
Secondary outcome [2] 415944 0
Peak force assessed by right knee extensor strength measured on an isokinetic dynamometer whilst seated with their arms folded across their chest and their hips and upper bodies strapped firmly to the seat.
Timepoint [2] 415944 0
pre and post training 12 weeks of training
Secondary outcome [3] 415945 0
Rate of force development was assessed by knee extensor muscle activation using the twitch interpolation technique. The electrical current was delivered using a single square-wave pulse with a width of 200 µs at 400 V. The current applied was increased in incremental steps until the resting M wave and evoked twitch torque amplitude plateaued. The current was then increased by a further 10% to ensure supra-maximal activation of the nerve.
Timepoint [3] 415945 0
Pre and post training 12 weeks of training
Secondary outcome [4] 415946 0
Time to peak force was assessed by knee extensor muscle activation using the twitch interpolation technique. The electrical current was delivered using a single square-wave pulse with a width of 200 µs at 400 V. The current applied was increased in incremental steps until the resting M wave and evoked twitch torque amplitude plateaued. The current was then increased by a further 10% to ensure supra-maximal activation of the nerve.
Timepoint [4] 415946 0
pre and post 12 weeks of training
Secondary outcome [5] 415947 0
half relaxation time was assessed by knee extensor muscle activation using the twitch interpolation technique. The electrical current was delivered using a single square-wave pulse with a width of 200 µs at 400 V. The current applied was increased in incremental steps until the resting M wave and evoked twitch torque amplitude plateaued. The current was then increased by a further 10% to ensure supra-maximal activation of the nerve.
Timepoint [5] 415947 0
Pre and post 12 weeks of training
Secondary outcome [6] 415948 0
Contraction duration was assessed by knee extensor muscle activation using the twitch interpolation technique. The electrical current was delivered using a single square-wave pulse with a width of 200 µs at 400 V. The current applied was increased in incremental steps until the resting M wave and evoked twitch torque amplitude plateaued. The current was then increased by a further 10% to ensure supra-maximal activation of the nerve.
Timepoint [6] 415948 0
Pre and post 12 weeks of training

Eligibility
Key inclusion criteria
Sedentary males aged 50 - 64 were eligible to participate who had not participated in any regular exercise for more than 6 months. Healthy non-smokers and free of any musculoskeletal injuries.
Minimum age
50 Years
Maximum age
65 Years
Sex
Males
Can healthy volunteers participate?
Yes
Key exclusion criteria
Recent contraindications to exercise, medications contraindicated to exercise, musculoskeletal injury causing inability to exercise, smoking history.

Study design
Purpose of the study
Treatment
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Other
Other design features
All participants will complete the same 12-week exercise training intervention, with outcome measures collected before and after completion of the intervention, and with participants acting as their own control
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
A priori power analysis for a repeated-measures ANOVA was performed with input parameters: effect size, Type I error probability of 0.05, desired statistical power of 0.80, number of groups, and number of measurements. A Shapiro-Wilk test for normality conducted and all data met the assumptions of linear statistics. The effect of training on measures obtained before and after the 12 week training program and pre and post the cycling time trials were identified through a paired t-test. Between and within group differences in measures obtained during the time trial identified through a repeated measures two-way ANOVA. The source of significance was located using uncorrected Fisher’s LSD test.

Data are presented as mean ± SD, significance set at P < 0.05. Effect sizes were calculated by dividing the difference in means by average standard deviation, and magnitudes were assessed using the following criteria: = 0.19 = trivial, 0.20–0.49 = small, 0.50–0.79 = moderate, and > 0.80 = large.

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
10/07/2012
Date of last participant enrolment
Anticipated
Actual
31/01/2014
Date of last data collection
Anticipated
Actual
30/04/2014
Sample size
Target
8
Accrual to date
Final
8
Recruitment in Australia
Recruitment state(s)
NSW
Recruitment postcode(s) [1] 38871 0
2795 - Bathurst

Funding & Sponsors
Funding source category [1] 312539 0
University
Name [1] 312539 0
Charles Sturt University
Country [1] 312539 0
Australia
Primary sponsor type
University
Name
Charles Sturt University
Address
Building 12.92
Panorama Ave
Bathurst, NSW 2795
Country
Australia
Secondary sponsor category [1] 314297 0
None
Name [1] 314297 0
Address [1] 314297 0
Country [1] 314297 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 311869 0
Charles Sturt University Human Research Ethics Committee
Ethics committee address [1] 311869 0
Ethics committee country [1] 311869 0
Australia
Date submitted for ethics approval [1] 311869 0
Approval date [1] 311869 0
09/07/2012
Ethics approval number [1] 311869 0

Summary
Brief summary
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 122662 0
Prof Francesco Marino
Address 122662 0
School of Allied Health, Exercise & Sports Science
Building 1292
Panorama Ave
Charles Sturt University
Bathurst NSW 2795
Country 122662 0
Australia
Phone 122662 0
+61 02 63384048
Fax 122662 0
Email 122662 0
[email protected]
Contact person for public queries
Name 122663 0
Francesco Marino
Address 122663 0
School of Allied Health, Exercise & Sports Science
Building 1292
Panorama Ave
Charles Sturt University
Bathurst NSW 2795
Country 122663 0
Australia
Phone 122663 0
+61 02 63384048
Fax 122663 0
Email 122663 0
[email protected]
Contact person for scientific queries
Name 122664 0
Francesco Marino
Address 122664 0
School of Allied Health, Exercise & Sports Science
Building 1292
Panorama Ave
Charles Sturt University
Bathurst NSW 2795
Country 122664 0
Australia
Phone 122664 0
+61 02 63384268
Fax 122664 0
Email 122664 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
Possible identification of individuals


What supporting documents are/will be available?




Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
SourceTitleYear of PublicationDOI
EmbaseSerum brain-derived neurotrophic factor (BDNF) and self-paced time-trial performance in older untrained men.2023https://dx.doi.org/10.1371/journal.pone.0285628
N.B. These documents automatically identified may not have been verified by the study sponsor.