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

NCT06924060 | Completed

• 1 other identifier: 81740024.5.0000.5153
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief 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. 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.

Conditions

Resistance Training; Eccentric Exercise Training

Keywords

randomized clinical trial; flywheel resistance training; hypertrophy; maximum voluntary isometric contraction

Outcome Measures

Primary Outcomes (7)

• 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.

  Baseline and after eight weeks

• 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.

  Baseline and after eight weeks

• 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.

  Baseline and after eight weeks

• 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.

  Baseline and after eight weeks

• 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).

  Baseline and after eight weeks

• 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.

  Baseline and after eight weeks

• 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.

  Baseline and after eight weeks

Secondary Outcomes (2)

• Delayed Onset Muscle Soreness

  Before each training session during the 8 weeks of intervention

• Subjective Perception of Effort

  Before each training session during the 8 weeks of intervention

Study Arms (3)

2 sets group

EXPERIMENTAL

Group 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).

Behavioral: Flywheel Resistance Training with two sets

4 sets group

EXPERIMENTAL

Group 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).

Behavioral: Flywheel Resistance Training with four sets

6 sets arm

EXPERIMENTAL

Group 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).

Behavioral: Flywheel Resistance Training with six sets

Interventions

Flywheel Resistance Training with two sets BEHAVIORAL

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).

Also known as: Flywheel Inertial Training, Eccentric Training

2 sets group

Flywheel Resistance Training with four sets BEHAVIORAL

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).

Also known as: Flywheel Inertial Training, Eccentric Training

4 sets group

Flywheel Resistance Training with six sets BEHAVIORAL

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).

Also known as: Flywheel Inertial Training, Eccentric Training

6 sets arm

Eligibility Criteria

• Age: 18 Years - 35 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• 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.

You may not qualify if:

• 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.

Sponsors & Collaborators

• Federal University of Vicosa: lead

Study Sites (1)

Federal University at Viçosa

Viçosa, Minas Gerais, 36570-900, Brazil

Location

MeSH Terms

Conditions

Hypertrophy

Condition Hierarchy (Ancestors)

Pathological Conditions, Anatomical; Pathological Conditions, Signs and Symptoms

Study Officials

• Osvaldo C Moreira, PhD supervisor

  Federal University of Viçosa

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: Hidden and opaque envelope technique
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: PhD Student

Study Record Dates

• First Submitted: March 31, 2025
• First Posted: April 11, 2025
• Study Start: April 28, 2025
• Primary Completion: July 4, 2025
• Study Completion: July 14, 2025
• Last Updated: August 6, 2025

Record last verified: 2025-08

Data Sharing

• IPD Sharing: Will not share

Locations

BR (1)