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Trial registered on ANZCTR


Registration number
ACTRN12619001497190
Ethics application status
Approved
Date submitted
9/10/2019
Date registered
30/10/2019
Date last updated
30/10/2019
Date data sharing statement initially provided
30/10/2019
Type of registration
Retrospectively registered

Titles & IDs
Public title
Effectiveness of strength “snacks” for improving strength, muscle mass, and muscular performance in healthy males.
Scientific title
Efficacy of strength “snacks” for improving strength, muscle mass, and neuromuscular performance in healthy males.
Secondary ID [1] 299507 0
Nil
Universal Trial Number (UTN)
U1111-1241-6893
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Loss of muscle mass and strength. 314751 0
Condition category
Condition code
Musculoskeletal 313079 313079 0 0
Normal musculoskeletal and cartilage development and function
Physical Medicine / Rehabilitation 313288 313288 0 0
Other physical medicine / rehabilitation

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
1. Efficacy of strength “snacks” for improving strength, muscle mass, and neuromuscular performance in healthy males.

2. Resistance training (RT) is the only known non-pharmacological intervention for improving strength and muscle mass, both of which play significant roles in maintaining and improving human health. Despite this, engagement in RT remains poor, with common barriers to participation including a lack of time and a high perception of difficulty associated with commonly-recommended RT programs. There is a need, therefore, for identification of RT interventions that are time efficient, low in complexity, and enjoyable to perform. Recent evidence suggests that high-load, low-volume RT can achieve outcomes that are similar-to-superior to traditional lower-load and higher-volume RT, with the added benefit of eliciting more positive affective responses (Buckner et al, 2018). Hence these RT protocols have the potential to promote more engagement in RT and be more sustainable long-term, both of which are likely to lead to improved population health outcomes. This project will provide new evidence for the effectiveness of low complexity, high-load and low-volume RT for improving strength, muscle mass, and neuromuscular performance, as well as the influence of these interventions for eliciting positive affective responses that may improve long-term RT adherence.

3. All of the necessary resources described below are currently available for use within the School of Exercise and Nutrition Sciences laboratories, Building J, Deakin University Burwood campus:
Resistance training intervention: Machine-based plate-loaded resistance training equipment, specifically leg press, chest press, seated row, leg extension, and leg curl machines.
Strength assessments: Dynamic (1-RM) strength assessment requires a leg press and chest press machine. Isometric (MVIC) strength assessment requires an isokinetic dynamometer.
Thigh muscle mass assessment: Requires a pQCT (peripheral quantitative computed tomography) scanner.
Body composition assessment: Requires a DXA (dual x-ray absorptiometry) scanner.
Neuromuscular performance assessment: Requires a portable force platform, isometric mid-thigh pull (IMTP) rig, and associated software (e.g., Ballistic Measurement System).
Subjective responses assessment: Requires access to the relevant questionnaires (session rating of perceived exertion, session rating of perceived discomfort, the feeling scale, perceived recovery scale, and the self-efficacy for exercise questionnaire), which are all freely available online.

4. Procedures
Study overview: The study will follow a randomised, parallel-group design. Participants will undertake one of two resistance training interventions for 8 weeks (2 sessions per week): 1) low-volume, high-load strength “snacking” (SNACK group) or 2) traditional higher-volume, lower-load resistance training (TRAD group).
The primary outcome measure will be maximal dynamic (1-RM) upper- and lower-body strength. Secondary outcome measures will be maximal isometric strength (MVIC), thigh muscle mass (pQCT), total body and regional lean mass and fat mass (DXA), neuromuscular performance (CMJ and IMTP), and affective responses to individual resistance training sessions and the entire resistance training intervention.

Familiarisation: During the first visit to the laboratory (PRE visit 1), participants will be familiarised with the maximal strength and neuromuscular performance assessments. This will involve completing these assessments in full (as described below), which will then be repeated when participants return to the laboratory the following week for PRE visits 2 and 3 (baseline testing). Participants will also practice performing each exercise to be performed in the resistance training program, with the aim of identifying appropriate starting training loads for each exercise.

Randomisation: After baseline testing (PRE visits 2 and 3), participants will be pair-matched based on 1-RM leg press strength and randomly allocated to either the SNACK or TRAD group. Group randomisation will be performed by the principal investigator (JF)

Resistance training intervention: Resistance training will consist of five exercises (leg press, chest press, seated row, leg extension, and leg curl) performed twice weekly for 8 weeks. One warm-up set (six repetitions at ~75% of load in each work set) will be performed for each exercise. The SNACK group will then perform a single set of six repetitions at the six-repetition maximum load (i.e., 6-RM; the load predicting momentary muscle failure on the 7th repetition), while the TRAD group will perform three work sets for each exercise at the 12-RM load (i.e., the load predicting momentary muscle failure on the 13th repetition). Two minutes of passive recovery will be allowed between sets for the TRAD group. Appropriate loads will be determined during familiarisation where participants will perform sets (of either six or twelve repetitions depending on the group) at increasing loads until the 6-RM (SNACK) or 12-RM (TRAD) is determined. Participants in both groups will be instructed to perform both the concentric and eccentric phase of each repetition in a controlled manner (~2 s). All resistance training sessions will be monitored by a qualified exercise professional and strong verbal encouragement will be provided during each work set. Once the researchers are confident participants could exceed the prescribed number of repetitions with the current load while maintaining correct form and movement control, load progression (~2.5-5 kg depending on the exercise) will be applied for the next training session.

Exercise/nutrition control: For 24 h before the first pre-testing visit, participants will be asked to avoid any structured exercise and record a detailed food (and fluid intake) diary. Participants will then be asked to replicate this dietary and fluid intake as closely as possible for the 24 h prior to all subsequent testing visits. On the morning of the pQCT and DXA scans (PRE visit 1 and POST visit 1), participants will be required to report to the laboratory after an 8-10 h fast.

5. All strength/neuromuscular performance testing and resistance training sessions will be implemented and supervised by qualified and experienced exercise professionals educated in exercise science/physiology. All DXA and pQCT scans will be performed by individuals who have undertaken clinical densitometry training and hold a current radiation use license with the Department of Health.

6. All testing sessions and the resistance training intervention will be delivered face-to-face.

7. All testing and resistance training sessions will be undertaken within the exercise physiology laboratories in Building J (levels 1 and 5), Deakin University, Melbourne Burwood campus.

8. Participants will undertake one of two resistance training interventions for 8 weeks (2 sessions per week): 1) low-volume, high-load strength “snacking” (SNACK group) or 2) traditional higher-volume, lower-load resistance training (TRAD group). Resistance training will consist of five exercises (leg press, chest press, seated row, leg extension, and leg curl). One warm-up set (six repetitions at ~75% of load in each work set) will be performed for each exercise. The SNACK group will then perform a single set of six repetitions at the six-repetition maximum load (i.e., 6-RM; the load predicting momentary muscle failure on the 7th repetition), while the TRAD group will perform three work sets for each exercise at the 12-RM load (i.e., the load predicting momentary muscle failure on the 13th repetition). Two minutes of passive recovery will be allowed between sets for the TRAD group. Appropriate loads will be determined during familiarisation where participants will perform sets (of either six or twelve repetitions depending on the group) at increasing loads until the 6-RM (SNACK) or 12-RM (TRAD) is determined. Participants in both groups will be instructed to perform both the concentric and eccentric phase of each repetition in a controlled manner (~2 s). All resistance training sessions will be monitored by a qualified exercise professional and strong verbal encouragement will be provided during each work set.

9. Resistance training loads will be individualised so that participants in the SNACK group will perform a single set of six repetitions at the six-repetition maximum load (i.e., 6-RM; the load predicting momentary muscle failure on the 7th repetition), while the TRAD group will perform three work sets for each exercise at the 12-RM load (i.e., the load predicting momentary muscle failure on the 13th repetition). Once the researchers are confident participants could exceed the prescribed number of repetitions with the current load while maintaining correct form and movement control, load progression (~2.5-5 kg depending on the exercise) will be applied for the next training session.

11. Adherence to the intervention will be determined as the number of resistance training sessions completed by participants compared to the total number planned (16 over 8 weeks).
Intervention code [1] 315760 0
Treatment: Other
Comparator / control treatment
The TRAD group will act as the comparator/control treatment.
Control group
Active

Outcomes
Primary outcome [1] 321626 0
Maximal dynamic (1-RM) lower-body strength assessed using a 45-degree incline leg press machine.
Timepoint [1] 321626 0
2-3 days before the intervention and 2-3 days after the intervention.
Primary outcome [2] 321771 0
Maximal dynamic (1-RM) upper-body strength assessed using a chest press machine.
Timepoint [2] 321771 0
2-3 days before the intervention and 2-3 days after the intervention.
Secondary outcome [1] 375645 0
Maximal voluntary isometric contraction (MVIC) strength of the knee extensors assessed using an isokinetic dynamometer.
Timepoint [1] 375645 0
2-3 days before the intervention and 2-3 days after the intervention.
Secondary outcome [2] 375646 0
Thigh muscle mass (pQCT).
Timepoint [2] 375646 0
2-3 days before the intervention and 2-3 days after the intervention.
Secondary outcome [3] 375647 0
Composite measures of body composition, including total body and regional lean mass and fat mass (assessed via DXA).
Timepoint [3] 375647 0
2-3 days before the intervention and 2-3 days after the intervention.
Secondary outcome [4] 375648 0
Composite measures of neuromuscular performance [countermovement jump (CMJ) and isometric mid-thigh pull (IMTP) performance] assessed using a portable force platform.
Timepoint [4] 375648 0
2-3 days before the intervention and 2-3 days after the intervention.
Secondary outcome [5] 375649 0
Composite measures of the affective responses to individual resistance training sessions, assessed using the rating of perceived exertion (RPE), rating of perceived discomfort (RPD), the feeling scale, and the perceived recovery scale.
Timepoint [5] 375649 0
All measures will be administered immediately after each resistance training session, apart from the perceived recovery scale, which will be administered at the start of each training session in weeks 1, 3, 5, 7, and the first post-testing session.
Secondary outcome [6] 376165 0
Affective responses to the entire resistance training intervention, assessed using the self-efficacy for exercise scale.
Timepoint [6] 376165 0
2-3 days before the intervention and 2-3 days after the intervention.

Eligibility
Key inclusion criteria
1. Male
2. Aged 18-35 years
3. Apparently healthy (as determined from the ESSA screening questionnaire) and without any current or previous cardiovascular or musculoskeletal conditions
Minimum age
18 Years
Maximum age
35 Years
Sex
Males
Can healthy volunteers participate?
Yes
Key exclusion criteria
1. Have performed any structured resistance training consistently (i.e., more than once per week for three consecutive weeks or more) in the previous 6 months

Study design
Purpose of the study
Prevention
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Allocation is not concealed.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Participants will be randomised to a training group via covariate adaptive randomisation based on baseline 1-RM leg press strength.
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint/s
Statistical methods / analysis
Based on previously reported magnitudes of muscle strength gain with low-volume RT in younger adults (Cohen’s d ES = 0.83, approximated to Cohen’s f = 0.415) (Ralston et al., 2017), power analysis (ß = 0.2, a = 0.05) indicated a sample size of 14 (7 per group) is sufficient to minimise the risk of type II errors. To accommodate a possible dropout rate of 15-20%, an additional 4 participants will be recruited.

Data will be analysed using a linear mixed models, with “time” (repeated measure), “group” and “group × time” as fixed factors, and “subject” as a random factor to determine the influence of group (high-load vs. low-load resistance training) on all dependent variables. The magnitude of changes in dependent variables and their associated uncertainty will be determined using standardised effect sizes (Cohen’s d) and 95% confidence limits, respectively. Statistical significance will be accepted as P <0.05.

Recruitment
Recruitment status
Recruiting
Date of first participant enrolment
Anticipated
Actual
14/10/2019
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
14
Accrual to date
4
Final
Recruitment in Australia
Recruitment state(s)
VIC

Funding & Sponsors
Funding source category [1] 303913 0
University
Name [1] 303913 0
Deakin University
Country [1] 303913 0
Australia
Primary sponsor type
University
Name
Deakin University
Address
221 Burwood Hwy, Burwood VIC 3125.
Country
Australia
Secondary sponsor category [1] 304063 0
None
Name [1] 304063 0
Address [1] 304063 0
Country [1] 304063 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 304417 0
Deakin University Human Research Ethics Committee
Ethics committee address [1] 304417 0
Ethics committee country [1] 304417 0
Australia
Date submitted for ethics approval [1] 304417 0
Approval date [1] 304417 0
13/09/2019
Ethics approval number [1] 304417 0

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

Contacts
Principal investigator
Name 96882 0
Dr Jackson Fyfe
Address 96882 0
Deakin University, 221 Burwood Hwy, Burwood VIC 3125.
Country 96882 0
Australia
Phone 96882 0
+613 5227 8779
Fax 96882 0
Email 96882 0
jackson.fyfe@deakin.edu.au
Contact person for public queries
Name 96883 0
Jackson Fyfe
Address 96883 0
Deakin University, 221 Burwood Hwy, Burwood VIC 3125.
Country 96883 0
Australia
Phone 96883 0
+613 5227 8779
Fax 96883 0
Email 96883 0
jackson.fyfe@deakin.edu.au
Contact person for scientific queries
Name 96884 0
Jackson Fyfe
Address 96884 0
Deakin University, 221 Burwood Hwy, Burwood VIC 3125.
Country 96884 0
Australia
Phone 96884 0
+613 5227 8779
Fax 96884 0
Email 96884 0
jackson.fyfe@deakin.edu.au

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

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

Documents added automatically
No additional documents have been identified.