Skip to main content
OpenTrials
Recruiting

NCT Number: NCT06532786

Neural Adaptations to Metronome-Paced Strength Training

The aim of the study is to investigate the effects of incorporating variability within Resistance Training (RT) methods on the neural adaptations along the corticospinal tract and on neuromuscular function. The literature suggests that RTis one of the most common modalities to enhance and restore muscle function and its practice results in adaptation in neural and morphological adaptations. It is also known that conditions such as ageing and injury have a negative impact on neural drive to the muscles with consequences at motor control level that are not addressed by traditional RT. Recent approaches such as metronome paced strength training have been used to cover this motor control dimension through a greater control and consciousness of movement. However, this methodology tends not to incorporate the inherent variability and complex, fractal-like fluctuations that characterize human movement. The investigators propose that incorporating variability through a fractal-like metronome approach will speed up the neural adaptations which will be useful in injury rehab.

Recruiting

Interested in participating?

Request Info

Key information

Conditions

Healthy

Age range

18 year–40 year

Sex eligibility

Male

Study type

Interventional

Phase

Not applicable

Primary location

Egas Moniz School of Health & Science

Almada, Monte de Caparica, 2829-699, Portugal

Location status: Recruiting

Location contact

João R. Vaz, PhD

CONTACT

[email protected]

967096444 ext. +351

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • aged between 18 and 40 years

Exclusion criteria

  • Neurologic conditions;
  • Lower limb disabilities or disease;
  • Not able to provide informed consent;
  • Have an implanted device (e.g. pacemakers) or any metal in the body;
  • Medication advised against the application of Transcranial Magnetic Stimulation;
  • History/family history of seizures, brain lesions or head trauma, neurological or psychiatric diseases, epilepsy, migraine

Treatment and study plan

Fractal Paced

Other

The intervention consists in a metronome-paced strength training session performed 3 times per week (with 48h of rest between sessions), during 4 weeks. Each session consists in 4 sets of 15 repetitions at 65% of the one-repetition maximal (1RM) in single leg extension machine, synchronizing each repetition with fractal external cues presented by a visual metronome. The rest between sets will be set at 2 minutes of rest between sets.

Isochronous Paced

Other

The intervention consists in a metronome-paced strength training session performed 3 times per week (with 48h of rest between sessions), during 4 weeks. Each session consists in 4 sets of 15 repetitions at 65% of the one-repetition maximal (1RM) single in leg extension machine, synchronizing each repetition with isochronus external cues presented by a visual metronome. The rest between sets will be set at 2 minutes of rest between sets.

Self Paced

Other

The intervention consists in a metronome-paced strength training session performed 3 times per week (with 48h of rest between sessions), during 4 weeks. Each session consists in 4 sets of 15 repetitions at 65% of the one-repetition maximal (1RM) in single leg extension machine, at their own self pace (with no metronome). The rest between sets will be set at 2 minutes of rest between sets.

Primary outcomes

  1. Corticospinal Excitability (CSE) changes across the 4-weeks intervention (PRE to Week1, Week 2, Week 3, POST and follow-up) both within and between Fractal paced, Isochronus Paced and Self paced groups

    Time frame: PRE (baseline), W1 (week 1), W2 (week 2), W3 (week 3), POST (week 4), FUP (follow-up 4 weeks after the end of intervention)

    CSE is a parameter extracted through the application of Transcranial Magnetic Stimulation (TMS). This parameter provides information regarding the level of excitability of the corticospinal tract.

  2. Short-interval Intracortical Inhibition (SICI) changes across the 4-weeks intervention (PRE to Week1, Week 2, Week 3, POST and follow-up) both within and between Fractal paced, Isochronus Paced and Self paced groups

    Time frame: PRE (baseline), W1 (week 1), W2 (week 2), W3 (week 3), POST (week 4), FUP (follow-up 4 weeks after the end of intervention)

    SICI is a parameter extracted through the application of Transcranial Magnetic Stimulation (TMS). This parameter provides information regarding the level of inhibition within the motor cortex.

  3. Corticospinal Silent Period (CSP) changes across the 4-weeks intervention (PRE to Week1, Week 2, Week 3, POST and follow-up) both within and between Fractal paced, Isochronus Paced and Self paced groups

    Time frame: PRE (baseline), W1 (week 1), W2 (week 2), W3 (week 3), POST (week 4), FUP (follow-up 4 weeks after the end of intervention)

    CSP is a parameter extracted through the application of Transcranial Magnetic Stimulation (TMS). This parameter provides information regarding the level of inhibition along the corticospinal tract.

  4. Intracortical Facilitation (ICF) changes across the 4-weeks intervention (PRE to Week1, Week 2, Week 3, POST and follow-up) both within and between Fractal paced, Isochronus Paced and Self paced groups

    Time frame: PRE (baseline), W1 (week 1), W2 (week 2), W3 (week 3), POST (week 4), FUP (follow-up 4 weeks after the end of intervention)

    ICF is a parameter extracted through the application of Transcranial Magnetic Stimulation (TMS). This parameter provides information regarding the level of facilitation within the motor cortex.

  5. Lumbar Evoked Potentials (LEP) changes across the 4-weeks intervention (PRE to Week1, Week 2, Week 3, POST and follow-up) both within and between Fractal paced, Isochronus Paced and Self paced groups

    Time frame: PRE (baseline), W1 (week 1), W2 (week 2), W3 (week 3), POST (week 4), FUP (follow-up 4 weeks after the end of intervention)

    LEP is a measure extracted through the aplication of Lumbar stimulation. This measure allow to distinguish the adaptations that occur at spinal level as a result of strength training.

  6. Maximal Compound Action Potentials (Mmax) changes across the 4-weeks intervention (PRE to Week1, Week 2, Week 3, POST and follow-up) both within and between Fractal paced, Isochronus Paced and Self paced groups

    Time frame: PRE (baseline), W1 (week 1), W2 (week 2), W3 (week 3), POST (week 4), FUP (follow-up 4 weeks after the end of intervention)

    Mmax is a measure assessed through peripheral nerve stimulation and represents the maximal capacity of recruit the motoneurons that innerve a muscle.

  7. StartReact Gain changes across the 4-weeks intervention (PRE to Week1, Week 2, Week 3, POST and follow-up) both within and between Fractal paced, Isochronus Paced and Self paced groups

    Time frame: PRE (baseline), W1 (week 1), W2 (week 2), W3 (week 3), POST (week 4), FUP (follow-up 4 weeks after the end of intervention)

    StartReact gain is a measure that is calculated following the StartReact protocol. It consists in measuring the participants' reaction times in response to visual stimuli (visual reaction time [VRT]), visual stimuli combined with a quiet sound (visual auditory reaction time [VART]) and visual startling stimuli (visual startling reaction time [VSRT]) and, then, apply the following formula: StartReact gain = ([VRT - VSRT]/[VRT - VART]).

Secondary outcomes

  1. Single leg extension 1RM changes after 4-weeks intervention (PRE to POST and follow-up) both within and between Fractal paced, Isochronus Paced and Self paced groups

    Time frame: PRE (baseline), POST (week 4), FUP (follow-up 4 weeks after the end of intervention)

    Single leg 1RM is defined as the maximal load that each participant mobilized in a single maximum dynamic knee extension.

  2. Maximal Voluntary Isometric Contraction (MVIC) changes across the 4-weeks intervention (PRE to Week1, Week 2, Week 3, POST and follow-up) both within and between Fractal paced, Isochronus Paced and Self paced groups

    Time frame: PRE (baseline), W1 (week 1), W2 (week 2), W3 (week 3), POST (week 4), FUP (follow-up 4 weeks after the end of intervention)

    MVIC is defined as the maximal force an individual can produce against an immovable resistance

  3. Sample Entropy (SampEn) changes across the 4-weeks intervention (PRE to Week1, Week 2, Week 3, POST and follow-up) both within and between Fractal paced, Isochronus Paced and Self paced groups

    Time frame: PRE (baseline), W1 (week 1), W2 (week 2), W3 (week 3), POST (week 4), FUP (follow-up 4 weeks after the end of intervention)

    SampEn is a non-linear measure of the temporal structure of force output, being an indicator of the regularity of this physiological output. It is obtained from sustained submaximal isometric contractions and it has been proposed as an indirect index of the capacity of the neuromuscular system to adapt the force output to changes in environment, i.e., its adaptability.

  4. Coefficient ov variation (CV) changes across the 4-weeks intervention (PRE to Week1, Week 2, Week 3, POST and follow-up) both within and between Fractal paced, Isochronus Paced and Self paced groups

    Time frame: PRE (baseline), W1 (week 1), W2 (week 2), W3 (week 3), POST (week 4), FUP (follow-up 4 weeks after the end of intervention)

    CV is a common linear measure that translates the amount of variability within the signal and is calculated through the standard deviation normalised to the mean of a time series

  5. Motor Unit Action Potentials (MUAP) changes across the 4-weeks intervention (PRE to Week1, Week 2, Week 3, POST and follow-up) both within and between Fractal paced, Isochronus Paced and Self paced groups

    Time frame: PRE (baseline), W1 (week 1), W2 (week 2), W3 (week 3), POST (week 4), FUP (follow-up 4 weeks after the end of intervention)

    MUAP is obtained through the decomposition of electromyographic (EMG) signals collected using High-density surface EMG electrodes and is an index of motor unit recruitment.

  6. Firing Rate (FR) changes across the 4-weeks intervention (PRE to Week1, Week 2, Week 3, POST and follow-up) both within and between Fractal paced, Isochronus Paced and Self paced groups

    Time frame: PRE (baseline), W1 (week 1), W2 (week 2), W3 (week 3), POST (week 4), FUP (follow-up 4 weeks after the end of intervention)

    FR is obtained through the decomposition of electromyographic (EMG) signals collected using High-density surface EMG electrodes and is a measure of intramuscular coordination

Study contacts

Contact information is provided by the study sponsor or research team.

João H Oliveira, MSc

CONTACT

[email protected]

913266232 ext. +351

João R Vaz, PhD

CONTACT

[email protected]

967096444 ext. +351

Sponsors and collaborators

Lead sponsor

Egas Moniz - Cooperativa de Ensino Superior, CRL

Other

Collaborators

  • Fundação para a Ciência e a Tecnologia

Registry information

Official study title

Neural Adaptations to Metronome-Paced Strength Training: Insights From Neuroscience and Human Movement Variability

Important dates

Study start
2024
Primary completion
2026
Study completion
2026
First posted
Aug 1, 2024
Registry last updated
Jan 16, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.