Effects of an Acute and Chronic Training Protocol Associated to the Inter-set Velocity Loss

Study Overview
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Brief Summary
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This study evaluates different performance, physiological and neuromuscular changes after acute and chronic resistance training intervention in physically active men. The participants will train with a single exercise (full squat) and will be monitored with a linear encoder. The experiment will consist of between 3 to 6 sets between 70% to 85% of 1RM in the full squat exercise. Two main groups will form the intervention: one group will perform inter-set repetitions until there will be a 20% of velocity loss compared to the first repetition, while the second group will have a 40% of velocity loss.

Detailed Description
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The main dependent variables and instruments will be: Tensyomiography: neuromuscular properties of the vastus lateral (VL), rectus femoris (RF) and vastus medialis (VM) from the dominant leg. Force platform: kinetic variables in relation to a countermovement jump. Near-infrared spectrography: oxygen saturation in the VL and VM. Termographic camera: low limbs temperatura. Linear encoder: mean propulsive velocity from each repetition Electromyography: amplitude and frequency parameters related to a knee extension maximum voluntary contraction test. Strain gauge: maximum isometric force.

Official Title
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Neuromuscular, Physiological and Performance Changes After an Acute and Chronic Training Protocol Associated to the Inter-set Velocity Loss

Conditions
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Healthy

Intervention / Treatment
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* Other: Acute changes
* Other: Chronic changes
* Other: Familiarization


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: To be healthy Without injuries or actual illnesses More than 2 years of experience in resistance training or federative sports Exclusion Criteria: To be sick or injured To have programmed during the intervention phase a dramatic change in the lifestyle

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 30 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 20% velocity loss<br>This group will train with a variable number of repetitions during each set. The group will stop the set once the mean propulsive velocity will be 20% less compared to the first repetition. | Other: Acute changes<br>* In a crossover design, participants will be randomized to perform on Day 1, 3 sets of repetitions (depending on each treatment group) at 70% or 1RM in the full squat exercise. 48-h later, same will be performed but in the contrary crossover arm.<br>Other: Chronic changes<br>* In a randomized control trial, participants will train during 6 weeks the full squat exercise, 2 days in the week (minimum between-days rest of 48h). Intensity will vary from 70% to 85 of 1RM, and training volume from 3 to 6 sets.<br>Other: Familiarization<br>* Prior to any intervention, all participants will perform a familiarization of the exercise session, together with a progressive resistance test to estimate the 1 RM<br>|
| Experimental: 40% velocity loss<br>This group will train with a variable number of repetitions during each set. The group will stop the set once the mean propulsive velocity will be 40% less compared to the first repetition. | Other: Acute changes<br>* In a crossover design, participants will be randomized to perform on Day 1, 3 sets of repetitions (depending on each treatment group) at 70% or 1RM in the full squat exercise. 48-h later, same will be performed but in the contrary crossover arm.<br>Other: Chronic changes<br>* In a randomized control trial, participants will train during 6 weeks the full squat exercise, 2 days in the week (minimum between-days rest of 48h). Intensity will vary from 70% to 85 of 1RM, and training volume from 3 to 6 sets.<br>Other: Familiarization<br>* Prior to any intervention, all participants will perform a familiarization of the exercise session, together with a progressive resistance test to estimate the 1 RM<br>|
| Placebo Comparator: Control group<br>This group will be just tested as a control group. | Other: Chronic changes<br>* In a randomized control trial, participants will train during 6 weeks the full squat exercise, 2 days in the week (minimum between-days rest of 48h). Intensity will vary from 70% to 85 of 1RM, and training volume from 3 to 6 sets.<br>Other: Familiarization<br>* Prior to any intervention, all participants will perform a familiarization of the exercise session, together with a progressive resistance test to estimate the 1 RM<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Contraction time | Time between 10% to 90% on the displacement-time curve assessed with the Tensiomiograhpy | 7 weeks | 
| Maximum displacement | Maximum displacement point the displacement-time curve assessed with the Tensiomiograhpy | 7 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Kinetic variables in the jump | Kinetic variables related to the force-time curve registered with the force platform during jumps | 7 weeks | 
| Muscle tissue oxygen | Oxygen in the muscle tissue assessed via near-infrared spectroscopy | 7 weeks | 
| Muscle temperature | Low limb muscles temperature assessed with a termographic camera | 7 weeks | 
| Mean propulsive velocity | Individual repetitions mean propulsive velocity during the full squat exercise, assessed with a linear encoder | 7 weeks | 
| Amplitude (RMS) and frequency outputs | Muscle electrical activity assessed with an EMG | 7 weeks | 
| Peak isometric force | Maximum force achieved during a knee extension at 120º | 7 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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velocity loss, Tensiomiography, resistance training