Myo-Reps Versus Traditional Sets for Muscle Strength, Fat-Free Mass, and Time Efficiency

October 30, 2026 updated by: Norwegian University of Science and Technology

Myo-Reps Versus Traditional Sets for Muscle Strength, Fat-Free Mass, and Time Efficiency: a Randomized Controlled Trial

This study compared two ways of doing strength training in healthy adults. The first, called Myo-Reps, is a time-saving method: one hard first set of 8-15 repetitions, followed by three short "mini-sets" of 3-5 repetitions with only 10-20 seconds of rest in between. The second is traditional training: three sets of 8-15 repetitions with 1-3 minutes of rest between sets.

Thirty-four adults were randomly assigned, by chance, to one of the two groups. For nine weeks everyone trained twice a week, under supervision, doing full-body workouts on 10 gym machines. The researchers measured how much stronger people became on each exercise, how much their fat-free mass (muscle and other lean tissue) changed, how hard the sessions felt, how much weight and how many repetitions were lifted, and how long the sessions took.

The aim was to find out whether the shorter Myo-Reps workouts can build strength and fat-free mass as well as traditional training.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Rationale: Lack of time is a common barrier to resistance training. The study tested two competing predictions. If total volume load (load × repetitions) is the main driver of adaptation, traditional three-set training should give greater improvements. If repetitions performed close to failure matter more, Myo-Reps could give similar or greater improvements despite less volume and shorter sessions.

Design: Parallel-group randomized trial in healthy adults, 1:1 allocation, stratified by gender and age, using a central web-based randomization system run by an independent trial unit; allocation was concealed until enrolment. All sessions were directly supervised, and load progression rules were identical in both groups. Week 1: familiarization and baseline body composition. Week 2: baseline strength testing. Weeks 3-11: training. Week 12: repeat testing.

Analysis: No sample-size calculation was performed (convenience sample). Strength comparisons are exploratory and analysed separately for each exercise.

Registration note: This record was registered retrospectively, after data collection was completed. Outcomes are described as defined in the manuscript submitted for publication.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
34

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Norway
    • Trøndelag
      • Trondheim, Trøndelag, Norway, 7030
        • Sit Trening HelgasetrSit

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years to 65 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • 18-65 years
  • Generally good health
  • No medical contraindications for heavy resistance training

Exclusion Criteria:

  • highly advanced trainees
  • pregnancy

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Myo-Rep

Nine weeks (weeks 3-11) of two supervised full-body sessions per week on 10 resistance-training machines. For each exercise: one activation set of 8-15 repetitions close to failure, followed by three mini-sets of 3-5 repetitions with the same load, separated by 10-20 seconds of rest. Load progression criteria were identical to the traditional training group.
Other: Myo-Reps resistance training

Supervised full-body machine-based resistance training, twice weekly for nine weeks. Each exercise: one activation set of 8-15 repetitions close to failure, then three mini-sets of 3-5 repetitions with the same load and 10-20 seconds of rest between sets.
Active Comparator: Traditional three-set training

Nine weeks (weeks 3-11) of two supervised full-body sessions per week on the same 10 resistance-training machines. For each exercise: three sets of 8-15 repetitions separated by 1-3 minutes of rest. Load progression criteria were identical to the Myo-Reps group.
Other: Traditional three-set resistance training

Supervised full-body machine-based resistance training, twice weekly for nine weeks, using the same 10 exercises. Each exercise: three sets of 8-15 repetitions with 1-3 minutes of rest between sets.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in exercise-specific muscular strength (estimated one-repetition maximum, e1RM) across 10 machine exercises
Time Frame: Baseline (week 2) to post-intervention (week 12)

e1RM was derived from 3-10 repetition-maximum tests (Epley equation) for each of the 10 trained machine exercises. Each exercise was analysed separately, and the between-group difference in change from baseline to post-intervention is the outcome.
Baseline (week 2) to post-intervention (week 12)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change in fat-free mass
Time Frame: Baseline (week 1) to post-intervention (week 12)

Measured by bioelectrical impedance (InBody 770).
Baseline (week 1) to post-intervention (week 12)
Session duration
Time Frame: Training weeks 3-11

Time taken to complete a training session, averaged per participant.
Training weeks 3-11
Weekly volume load
Time Frame: Training weeks 3-11

Load × repetitions, summed across exercises and averaged per week.
Training weeks 3-11
Repetitions close to failure
Time Frame: raining weeks 3-11

Estimated number of repetitions performed close to muscular failure during training.
raining weeks 3-11
Session rating of perceived exertion (session RPE)
Time Frame: Training weeks 3-11

Participant-rated exertion for each training session.
Training weeks 3-11

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Norwegian University of Science and Technology

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Marius S Fimland, Phd, NTNU - Norwegian University of Science and Technology

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
August 26, 2025

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 3, 2025

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 3, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
October 26, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 30, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
November 3, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
November 3, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 30, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
October 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • SIKT ID: 187305

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

De-identified individual participant data underlying the published results will be made available to qualified researchers on reasonable request to the corresponding author, after publication of the main article. Requests should include a brief research proposal.

IPD Sharing Time Frame

Data will be available beginning after publication of the main article and for at least 5 years thereafter.

IPD Sharing Access Criteria

De-identified individual participant data will be shared with qualified researchers on reasonable request to the corresponding author (Philip Meisterl, NTNU), who will review each request. Requesters should provide a short research proposal. Data are shared only for scientific research purposes, consistent with participants' consent and Norwegian data protection regulations (GDPR). Data will be sent securely by email or a secure file-transfer link.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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