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Trial registered on ANZCTR

Registration number

ACTRN12626001355369

Ethics application status

Approved

Date submitted

25/10/2026

Date registered

10/11/2026

Date last updated

10/11/2026

Date data sharing statement initially provided

10/11/2026

Type of registration

Prospectively registered

Titles & IDs

Public title

Adaptations of Soleus Muscle Architecture Following Eccentric Seated and Standing Calf Raise Training in Healthy, Recreationally Active Adults.

Scientific title

Effects of Eight Weeks of Seated Versus Standing Eccentric Calf Raise Training on Soleus Fascicle Length in Healthy, Recreationally Active Adults: A Randomised Controlled Trial.

Additional trial identifiers [1]

Nil

Universal Trial Number (UTN)

Trial acronym

Related trial records

Health condition

Health condition(s) studied:

Musculoskeletal health

Condition category

Condition code

Musculoskeletal

Normal musculoskeletal and cartilage development and function

Physical Medicine / Rehabilitation

Physiotherapy

Intervention/exposure

Study type

Interventional

Description of the intervention or exposure

Arm 1: Seated Eccentric Calf Raise Training
Participants allocated to Arm 1 will complete an eight-week supervised seated eccentric calf raise training program. Training will be conducted twice weekly, with a minimum of 48 hours between sessions. Each session will last approximately 30 minutes, comprising a 5–10-minute standardised warm-up followed by seated eccentric calf raise exercises.

The intervention will be delivered face-to-face, individually, by a registered physiotherapist at the Macquarie University Sport and Aquatic Centre or University of New South Wales Fitness and Aquatic Centre.

Participants will perform seated calf raises using a seated calf raise machine, with the knee flexed to approximately 90°. Each repetition will involve a bilateral concentric phase (raising both heels over approximately one second), a one-second pause at peak plantarflexion, followed by a unilateral eccentric phase (lowering one heel over three seconds). Exercises will be performed through the full available range of ankle dorsiflexion and plantarflexion, with the movement tempo standardised using a metronome.

Participants will complete 2–4 sets of 6–12 repetitions, progressing from two sets in weeks 1–2 to three sets in weeks 3–4 and four sets in the subsequent weeks. A two-minute rest period will be provided between sets. Eccentric exercise loading will be prescribed at 100% of maximal voluntary isometric contraction (MVIC), determined through plantarflexion strength testing. MVIC will be reassessed at the intervention midpoint to guide loading progression.

Arm 2: Standing Eccentric Calf Raise Training
Participants allocated to Arm 2 will complete an eight-week supervised standing eccentric calf raise training program. Training frequency, session duration, supervision, warm-up, exercise tempo, sets, repetitions, rest periods and loading progression will be identical to Arm 1.

The intervention will be delivered face-to-face, individually, by a registered physiotherapist at the Macquarie University Sport and Aquatic Centre or University of New South Wales Fitness and Aquatic Centre.

Participants will perform standing calf raises using a Smith machine while standing on a 20 cm elevated platform, with the knee extended to approximately 0°. Each repetition will involve a bilateral concentric phase, a one-second pause at peak plantarflexion, followed by a unilateral eccentric lowering phase over three seconds. Participants will perform exercises through the full available range of ankle dorsiflexion and plantarflexion.

Participants will complete 2–4 sets of 6–12 repetitions, progressing from two sets in weeks 1–2 to three sets in weeks 3–4 and four sets in the subsequent weeks. A two-minute rest period will be provided between sets. Eccentric exercise loading will be prescribed at 100% of MVIC and reassessed at the intervention midpoint to guide progression.

Intervention Adherence and Monitoring
All 16 training sessions will be supervised by the primary investigator, a registered physiotherapist. Adherence will be monitored through attendance records and individual training logs documenting exercise load, sets, repetitions, prescribed tempo and session rating of perceived exertion.

Intervention code [1]

Treatment: Other

Description of the comparator or control

The active comparator will be an eight-week supervised standing eccentric calf raise training program. Participants will complete two 30-minute sessions per week, supervised face-to-face by a registered physiotherapist at Macquarie University or the University of New South Wales. The program will involve standing eccentric calf raises using a Smith machine, with exercise loading, sets, repetitions and progression matched to the seated eccentric calf raise intervention.

Before commencing the intervention, all participants will complete a randomly allocated baseline observation period lasting 2–8 weeks. During this period, participants will maintain their usual physical activity levels while refraining from initiating new calf-strengthening exercises. Following the observation period and pre-intervention assessments, participants will be randomly allocated to one of the two training groups.

Control group

Active

Outcomes

Primary outcome [1]

Soleus fascicle length

Timepoint [1]

Baseline (week 0, before the 2–8-week observation period); pre-intervention (following the 2–8-week observation period, primary start point); mid-intervention (week 4 of training); and post-intervention (week 8 of training, primary endpoint).

Secondary outcome [1]

Soleus muscle thickness

Timepoint [1]

Baseline (week 0, before the 2–8-week observation period); pre-intervention (following the 2–8-week observation period); mid-intervention (week 4 of training); and post-intervention (week 8 of training).

Secondary outcome [2]

Soleus pennation angle

Timepoint [2]

Secondary outcome [3]

Seated plantarflexion strength

Timepoint [3]

Secondary outcome [4]

Standing plantarflexion strength

Timepoint [4]

Secondary outcome [5]

Calf raise endurance

Timepoint [5]

Secondary outcome [6]

Plyometric performance outcomes

Timepoint [6]

Eligibility

Key inclusion criteria

1. Healthy adults aged 18–35 years, of any gender.
2. Recreationally active, defined as participating in structured physical activity (including running or recreational sport) at least three times per week for a minimum of 30 minutes per session.
3. Able to attend all scheduled training and assessment sessions.
4. Able to perform a full-range calf raise against gravity without pain (self-assessed).
5. Cleared for participation in physical activity based on the Physical Activity Readiness Questionnaire (PAR-Q).
6. Able to read and comprehend the Participant Information and Consent Form (PICF), which is provided in English.

Minimum age

18 Years

Maximum age

35 Years

Sex

Both males and females

Healthy volunteers

Yes

Key exclusion criteria

1. Current lower-limb injury at the time of enrolment that is expected to persist until study commencement.
2. Currently undertaking a periodised training program in preparation for a specific sporting event.
3. Neurological or metabolic disorders that may impair muscle metabolism.
4. Use of anabolic steroids, growth hormones, or other performance-enhancing substances not approved by the Australian Sports Anti-Doping Authority (ASADA).

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 will be concealed using sealed opaque envelopes prepared by an independent researcher. Group allocation will be revealed only after completion of baseline assessments.

Methods used to generate the sequence in which subjects will be randomised (sequence generation)

Computer-generated random sequences will be used for both stages of randomisation. Participants will initially be randomly allocated to a baseline observation period of 2–8 weeks. Following completion of this period and pre-intervention assessments, participants will be randomly allocated in a 1:1 ratio to either seated eccentric calf raise training or standing eccentric calf raise training using a centralised computer-based randomisation system.

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

Statistical methods / analysis

There is limited evidence quantifying the expected between-group difference in soleus fascicle length following seated versus standing eccentric calf-raise training. In the absence of a robust effect size estimate, the sample size was determined a priori using a conservative small effect size, with 80% statistical power and an alpha level of 0.05. An allowance for participant attrition was included in the final recruitment target.

Recruitment

Recruitment status

Not yet recruiting

Date of first participant enrolment

Anticipated

7/12/2026

Actual

Date of last participant enrolment

Anticipated

1/02/2027

Actual

Date of last data collection

Anticipated

4/10/2027

Actual

Sample size

Target

Accrual to date

Final

Recruitment in Australia

Recruitment state(s)

NSW

Funding & Sponsors

Funding source category [1]

University

Name [1]

Macquarie University

Address [1]

Country [1]

Australia

Funding source category [2]

Other Collaborative groups

Name [2]

Greater Western Sydney Giants

Address [2]

Country [2]

Australia

Funding source category [3]

University

Name [3]

University of New South Wales

Address [3]

Country [3]

Australia

Primary sponsor type

University

Name

Macquarie University

Address

Country

Australia

Secondary sponsor category [1]

Other Collaborative groups

Name [1]

Greater Western Sydney Giants

Address [1]

Country [1]

Australia

Secondary sponsor category [2]

Other Collaborative groups

Name [2]

University of New South Wales

Address [2]

Country [2]

Australia

Ethics approval

Ethics application status

Approved

Ethics committee name [1]

Macquarie University Human Research Ethics Committee Medical Sciences

Ethics committee address [1]

https://www.mq.edu.au/research/ethics-integrity-and-policies/ethics/human-ethics

Ethics committee country [1]

Australia

Date submitted for ethics approval [1]

30/06/2026

Approval date [1]

20/07/2026

Ethics approval number [1]

520262049269153

Summary

Brief summary

This study will investigate whether seated or standing eccentric calf-raise training produces greater changes in the structure of the soleus (calf) muscle. Participants will complete an eight-week calf-strengthening program using either seated or standing calf raises. We expect that seated calf raises will produce greater increases in soleus fascicle length. Changes in soleus muscle structure, calf strength, endurance and jumping performance will be measured before and after the training program. The findings may help identify which calf-raise exercise is more effective for targeting the soleus during training and rehabilitation.

Trial website

Trial related presentations / publications

Public notes

Contacts

Principal investigator

Name

Dr Eoin Doyle

Address

Level 3, 75 Talavera Rd, Macquarie University, NSW 2109

Country

Australia

Phone

+61 2 9850 6613

Fax

[email protected]

Contact person for public queries

Name

Eoin Doyle

Address

Level 3, 75 Talavera Rd, Macquarie University, NSW 2109

Country

Australia

Phone

+61 2 9850 6613

Fax

[email protected]

Contact person for scientific queries

Name

Eoin Doyle

Address

Level 3, 75 Talavera Rd, Macquarie University, NSW 2109

Country

Australia

Phone

+61 2 9850 6613

Fax

[email protected]

Data sharing statement

Will the study consider sharing individual participant data?

Yes

Will there be any conditions when requesting access to individual participant data?

Persons/groups eligible to request access:
• Anyone

• Researchers
Conditions for requesting access:
• No requirements

What individual participant data might be shared?

• All de-identified individual participant data

What types of analyses could be done with individual participant data?

• Any type of analysis (i.e. no restrictions on data re-use)

When can requests for individual participant data be made (start and end dates)?

From:
After publication of main results
To:
No end date

Where can requests to access individual participant data be made, or data be obtained directly?

• Data repository: De-identified individual participant data will be made available in an open-access research data repository following publication of the main trial results.

• Email of trial custodian, sponsor or committee: Researchers may also contact the corresponding author, Kathryn Mills ([email protected]).

Are there extra considerations when requesting access to individual participant data?

What supporting documents are/will be available?

Type	Citation	Link	Email	Other Details	Attachment
Ethical approval					Letter of Ethics Approval July 2026.pdf
Informed consent form					CLEAN Particiapnt Information and Consent Form (PICF) Study 4 .docx
Study protocol					RCT_Protocol_FINAL.docx

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.

Trial Review

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Documents added automatically