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

Not Applicable

• Conditions: Healthy
• Interventions: Other: Acute changes; Other: Chronic changes; Other: Familiarization

• Registration Number: NCT03964519
• Lead Sponsor: Alejandro Muñoz López

Brief Summary

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

The main dependent variables and instruments will be:

1. Tensyomiography: neuromuscular properties of the vastus lateral (VL), rectus femoris (RF) and vastus medialis (VM) from the dominant leg.

2. Force platform: kinetic variables in relation to a countermovement jump.

3. Near-infrared spectrography: oxygen saturation in the VL and VM.

4. Termographic camera: low limbs temperatura.

5. Linear encoder: mean propulsive velocity from each repetition

6. Electromyography: amplitude and frequency parameters related to a knee extension maximum voluntary contraction test.

7. Strain gauge: maximum isometric force.

Study Timeline

• Status Verified: 2019-05
• Study First Submitted: 2019-05-23
• Study First Submitted QC: 2019-05-23
• Last Update Submitted: 2019-05-24
• Study First Posted: 2019-05-28
• Last Update Posted: 2019-05-29
• Study Start: 2019-07-01
• Primary Completion: 2019-08-30
• Study Completion: 2019-09-15

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: Male
• Target Recruitment: 30

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
20% velocity loss	Acute changes	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.
20% velocity loss	Familiarization	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.
20% velocity loss	Chronic changes	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.
Control group	Familiarization	This group will be just tested as a control group.
40% velocity loss	Familiarization	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.
Control group	Chronic changes	This group will be just tested as a control group.
40% velocity loss	Acute changes	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.
40% velocity loss	Chronic changes	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.

Primary Outcome Measures

Name	Time	Method
Contraction time	7 weeks	Time between 10% to 90% on the displacement-time curve assessed with the Tensiomiograhpy
Maximum displacement	7 weeks	Maximum displacement point the displacement-time curve assessed with the Tensiomiograhpy

Secondary Outcome Measures

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