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Resistance TrainingRCTNCT06924060

EFFECT OF RESISTANCE TRAINING VOLUME WITH INERTIAL FLYWHEEL ON MUSCLE ADAPTATIONS IN UNTRAINED MEN

A study testing Flywheel Resistance Training with two sets, Flywheel Resistance Training with four sets and Flywheel Resistance Training with six sets in people with Resistance Training and Eccentric Exercise Training, run by Federal University of Vicosa at 1 site in Brazil.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Muscular strength is essential for health and quality of life, impacting body composition, balance, locomotion, functional independence, and mental health. Resistance training (RT) is the primary way to increase strength and muscle hypertrophy. Read more about this study

Who is it for?
Ages 18 to 35 years, men onlyHealthy volunteers can take part
What is being tested?
Flywheel Resistance Training with two sets, Flywheel Resistance Training with four sets and Flywheel Resistance Training with six sets
Could I receive a placebo?
No, everyone receives an active treatment
How many people
30 participants
Where
1 siteBrazil
Study dates
28 Apr 2025to 14 Jul 2025
Phase
Interventional
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 35 years
  • Men only
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • Self-reported levels of speaking, writing and understanding Portuguese;
  • Availability to participate in the research (initial meeting, initial and final tests, data collection);
  • Have not been performing traditional resistance exercises for at least 6 months (untrained subjects);
  • Have no previous experience with inertial flywheel devices;
  • Answer no to all questions on the Physical Activity Risk Questionnaire - PAR-Q;
  • Have no medical contraindication of any kind.

Who cannot join

  • Have a history of recent osteomyoarticular injury;
  • Have uncontrolled chronic diseases;
  • Surgical procedures scheduled during interventions;
  • Do not have the flexibility to adapt their diet to the guidelines offered during collection;
  • Use medications or supplements that may interfere with the result, acting as an intervening variable.

Trial locations and contacts

1 site in 1 country.

Brazil1 site
  • Federal University at Viçosa

    Viçosa, Minas Gerais, 36570-900

Other trials in Brazil

About this study

Official title: EFFECT OS RESISTANCE TRAINING VOLUME WITH INERTIAL FLYWHEEL ON MUSCLE ADAPTATIONS IN UNTRAINED MEN: A RANDOMIZED CLINICAL TRIAL

Muscular strength is essential for health and quality of life, impacting body composition, balance, locomotion, functional independence, and mental health. Resistance training (RT) is the primary way to increase strength and muscle hypertrophy. Traditionally, RT programs rely on gravity, which can limit muscle activation, especially during the eccentric phase of movement. To improve outcomes, it is important to include methods that intensify muscle work during this phase.

Flywheel resistance Training (FWRT) was developed to increase overload during the eccentric phase by harnessing the energy generated during the concentric phase and applying it to the eccentric phase. This type of training has shown positive results in several studies, improving strength, hypertrophy, jump performance, aerobic endurance, agility, and running economy.

However, there are still no studies that define how the variables of FWRT should be effectively prescribed. Properly adjusting these variables can optimize muscle adaptations and improve physical fitness and health indices. Therefore, in this study, the number of sets will be evaluated to investigate whether a higher number of sets can lead to greater muscle adaptations.

Read the detailed description

Thirty young men will be randomly assigned to three groups: 2 sets, 3 sets, and 4 sets of Flywheel Resistance Training (FWRT). The interventions will take place at the Department of Physical Education at the Federal University of Vicosa, with all sessions supervised by certified physical education professionals. Follow-up will be conducted through WhatsApp messages and phone calls. All groups will train twice a week for eight weeks. Participants from all experimental groups will perform FWRT on a multi-leg isoinertial machine targeting both upper and lower body muscles. Each session will include 4 exercises, performed for 8 repetitions, with a 2-minute rest between sets and exercises. Training progression will be adjusted based on the participant's ability to exceed the suggested maximum repetitions with the same mobilized weight. The exercises will target various muscle groups, including leg extensions, leg curls, bicep curls, and triceps french press.

Participants will be evaluated at two points during the training program: pre-intervention and post-intervention. Muscle strength of the upper and lower limbs will be assessed through one-repetition maximum (1RM) tests on a knee extension or elbow flexion machine and through maximum voluntary isometric contraction (MVIC), evaluated with a load cell. The muscle thickness of the knee extensors and elbow flexors will be measured using a B-mode ultrasound. Load control will be monitored through the following scales: Total Quality of Recovery (TQR) and Visual Analog Scale for Delayed Onset Muscle Soreness (VAS-DOM), and after each set, by the Subjective Perception of Effort (OMNI-RES). To ensure adequate protein intake, at the end of each training session, participants will receive a dose of Whey Protein, based on data collected from their initial food recall and determined by a nutritionist. Anthropometric evaluation will include the measurement of: a) body mass using an electronic/digital scale with 100g resolution , and b) height using a millimetric stadiometer. The procedures used for body mass and height measurement will follow the protocols based on the measurement standards of the International Society for the Advancement of Anthropometry.

Being tested
Flywheel Resistance Training with two sets, Flywheel Resistance Training with four sets, Flywheel Resistance Training with six sets
Keywords
randomized clinical trial, flywheel resistance training, hypertrophy, maximum voluntary isometric contraction
Medical subject headings
Hypertrophy

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Flywheel Resistance Training with two setsBehavioural

    Also called Flywheel Inertial Training, Eccentric Training

    For each training session, 4 generic exercises will be performed, involving small and large muscle groups (leg extension, leg flexion, biceps curl, triceps french press). They will perform 2 sets of 8 repetitions, with a 2-minute break between exercises and sets. They will perform these exercises at a high intensity (always 10 on the OMNI-RES Scale).

  • Flywheel Resistance Training with four setsBehavioural

    Also called Flywheel Inertial Training, Eccentric Training

    For each training session, 4 generic exercises will be performed, involving small and large muscle groups (leg extension, leg flexion, biceps curl, triceps french press). They will perform 4 sets of 8 repetitions, with a 2-minute break between exercises and sets. They will perform these exercises at a high intensity (always 10 on the OMNI-RES Scale).

  • Flywheel Resistance Training with six setsBehavioural

    Also called Flywheel Inertial Training, Eccentric Training

    For each training session, 4 generic exercises will be performed, involving small and large muscle groups (leg extension, leg flexion, biceps curl, triceps french press). They will perform 6 sets of 8 repetitions, with a 2-minute break between exercises and sets. They will perform these exercises at a high intensity (always 10 on the OMNI-RES Scale).

Study groups in NCT06924060
Study groupRoleWhat they receive
2 sets groupExperimentalGroup that will perform two sets of each exercise developed during the intervention. The other training variables will be identical (repetitions, moment of inertia, rest intervals between sets and repetitions, rest intervals between workouts, training frequency, number and order of exercises).
Receives: Behavioral: Flywheel Resistance Training with two sets
4 sets groupExperimentalGroup that will perform four sets of each exercise developed during the intervention. The other training variables will be identical (repetitions, moment of inertia, rest intervals between sets and repetitions, rest intervals between workouts, training frequency, number and order of exercises).
Receives: Behavioral: Flywheel Resistance Training with four sets
6 sets armExperimentalGroup that will perform six sets of each exercise developed during the intervention. The other training variables will be identical (repetitions, moment of inertia, rest intervals between sets and repetitions, rest intervals between workouts, training frequency, number and order of exercises).
Receives: Behavioral: Flywheel Resistance Training with six sets

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Maximum isometric voluntary contraction (upper extremities)

    To evaluate the Maximum isometric voluntary contraction (MIVC) of the upper extremities, a load cell or extensometric cell with a sampling frequency of 1000 Hz will be used.

    Measured: Baseline and after eight weeks

  2. Maximum isometric voluntary contraction (lower extremities)

    To evaluate the Maximum isometric voluntary contraction (MIVC) of the lower extremities, a load cell or extensometric cell with a sampling frequency of 1000 Hz will be used.

    Measured: Baseline and after eight weeks

  3. 1 RM test (elbow flexors)

    To perform the one repetition maximum (1RM) test, the load cell will be placed on a Cross Over machine (Scorpions Fitness, Brazil), so that one of its ends is fixed by means of a chain to the lower part of a stirrup-type handle and the other end is fixed to the steel cable, which is subjected to traction when the machine's lever arm is moved. Before performing the test, the device will be adjusted so that the subject's elbow is at a 90° flexion angle.

    Measured: Baseline and after eight weeks

  4. 1 RM test (knee extension)

    To perform the one repetition maximum test (1RM), the knee extension exercise or elbown flexion will be used on a BH fitness® Nevada Pro-t extension machine. To perform the test, the volunteer will be asked to extend the knee to form an angle of approximately 180° (final position) and return to the initial position.

    Measured: Baseline and after eight weeks

  5. Muscle power (upper extremities)

    The evaluation of power elbow flexors will be assessed using the same machine used to assess 1RM. The load for assessing power should be used, obtained from the percentage value of 1RM (40%, 60% and 80% of 1RM), so that the subject performs the elbow flexion movement (concentric phase of the movement) at the highest possible speed. The return of the elbow to the initial position will be performed in a controlled manner, with a pause of one to two seconds, to prevent the effect of the accumulated elastic force from interfering with the next execution. A linear position transducer or Encoder will be used, with a sampling frequency of 1000 Hertz to determine the power values. Through this instrument it will be possible to obtain information on average muscle power (MMP) and peak muscle power (PP).

    Measured: Baseline and after eight weeks

  6. Muscle power (lower extremities)

    The evaluation of lower limb muscle power will be performed using the same knee extension machine used in the exercise sessions, starting from the same initial position (90º of kneeling flexion) and reaching the same final position (180º of knee extension) as the test of 1RM. The load for assessing power should be used, obtained from the percentage value of 1RM (40%, 60% and 80% of 1RM), so that the subject performs the knee extension movement (concentric phase of the movement) at the highest possible speed. The return of the knee to the initial position will be performed in a controlled manner, with a pause of one to two seconds, to prevent the effect of the accumulated elastic force from interfering with the next execution. A linear position transducer or Encoder will be used, with a sampling frequency of 1000 Hertz.

    Measured: Baseline and after eight weeks

  7. Muscle adaptations

    The muscle thickness of the knee extensors and elbow flexors will be measured using a B-mode ultrasound. Image acquisition will be performed by an experienced and previously trained researcher. The image will be considered suitable for analysis when the muscle-bone and subcutaneous adipose tissue-muscle interfaces are identified. The image will then be saved and analyzed in Image-J by the same experienced evaluator.

    Measured: Baseline and after eight weeks

Secondary outcomes (2)
  1. Delayed Onset Muscle Soreness

    To assess the history of Delayed Onset Muscle Soreness, the Visual Analog Scale for Delayed Onset Muscle Soreness (VAS-DOM) will be used to identify whether there are changes throughout the intervention for this variable, that is, whether the volunteer gets used to the intervention and feels less pain throughout the sessions.

    Measured: Before each training session during the 8 weeks of intervention

  2. Subjective Perception of Effort

    To assess the subjective perception of effort, the Subjective Perception of Effort (OMINI-RES) scale will be used, in order to identify whether there are changes throughout the intervention for this variable, that is, whether the volunteer gets used to the intervention and feels a lower perception of effort throughout the sessions.

    Measured: Before each training session during the 8 weeks of intervention

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted11 Apr 2025
  2. Study start28 Apr 2025
  3. Primary completion4 Jul 2025
  4. Study completion14 Jul 2025

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
Double blind
Who is masked
Investigator, Outcomes assessor
Enrolment
30 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT06924060
Sponsor's protocol ID
81740024.5.0000.5153
Acronym
RCT
Status last verified
Aug 2025
First submitted
31 Mar 2025
Last updated
6 Aug 2025
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A study testing Flywheel Resistance Training with two sets, Flywheel Resistance Training with four sets and Flywheel Resistance Training with six sets in people with Resistance Training and Eccentric Exercise Training, run by Federal University of Vicosa at 1 site in Brazil.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 6 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 6 Aug 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Brazil. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Maximum isometric voluntary contraction (upper extremities) (time frame: Baseline and after eight weeks). The study lists 7 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 6 Aug 2025.

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