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Neural Adaptations to Metronome-Paced Strength Training

Not Applicable
Recruiting
Conditions
Healthy
Interventions
Other: Self Paced
Other: Isochronous Paced
Other: Fractal Paced
Registration Number
NCT06532786
Lead Sponsor
Egas Moniz - Cooperativa de Ensino Superior, CRL
Brief Summary

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.

Detailed Description

Not available

Recruitment & Eligibility

Status
RECRUITING
Sex
Male
Target Recruitment
60
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

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Self PacedSelf PacedStrength training in single leg extension machine at participants self pace.
Isochronous PacedIsochronous PacedStrength training in single leg extension machine, synchronizing each repetition with a isochronus visual metronome, i.e., a metronome presenting visual external cues withthe same pace in each repetition (without variability)
Fractal PacedFractal PacedStrength training in single leg extension machine, synchronizing each repetition with a fractal-like visual metronome, i.e., a metronome presenting visual external cues with variability within its temporal structure.
Primary Outcome Measures
NameTimeMethod
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 groupsPRE (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.

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 groupsPRE (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 = (\[VRT - VSRT\]/\[VRT - VART\]).

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 groupsPRE (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.

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 groupsPRE (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.

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 groupsPRE (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.

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 groupsPRE (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.

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 groupsPRE (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.

Secondary Outcome Measures
NameTimeMethod
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 groupsPRE (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

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 groupsPRE (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

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 groupsPRE (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.

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 groupsPRE (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.

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 groupsPRE (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.

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 groupsPRE (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

Trial Locations

Locations (1)

Egas Moniz School of Health & Science

🇵🇹

Almada, Monte De Caparica, Portugal

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