Effects of Warm-up Intensity and Blood Flow Restriction

Study Overview
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Brief Summary
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Introduction: warming up has the function of preparing the body structures for a given task to be performed during sports, increasing body and muscle temperature, focusing on improving performance. Therefore, the use of the blood flow restriction technique (BFR) can be seen as a promising alternative for promoting greater mechanical and muscular stress, thus providing a more efficient warm-up and optimizing performance. Objectives: to analyze the effects of RFS used during low-intensity warm-up compared with low-intensity and high-intensity warm-up without RFS on performance (jump test and 30-meter sprint test) and skin surface temperature. In addition to analyzing and comparing, after the warm-up protocols with and without RFS, the acute responses on perceptual outcomes (perception of pain, change in sensitivity, subjective perception of exertion and perception of discomfort in relation to RFS) and muscle outcomes (tonus , muscle stiffness and elasticity). Methods: a randomized controlled clinical trial will be carried out, with 33 amateur soccer players aged between 18 and 35 years who will be randomly divided into three groups: low-intensity warm-up without RFS (30% VO2max), high-intensity warm-up without RFS ( 80% VO2max) and low-intensity warm-up associated with BFR (80% of total occlusion pressure) [30% VO2max-BFR]. All groups will carry out the heating protocol and the outcomes will be evaluated at baseline and immediately after the end of the heating, as well as 10 and 20 minutes after its completion, namely: skin surface temperature through thermography; tone, stiffness and muscle elasticity by myotometry, subjective perception of pain (VAS); pain threshold through the pressure algometer; subjective perception of exertion (BORG scale); perception of discomfort in relation to RFS (LIKERT-CR-10 scale); 30-meter sprints measured through photocells and vertical jump, measured through the force platform. Descriptive statistics will be used and comparisons will be made using the generalized linear mixed model, assuming a significance level of p<0.05.

Official Title
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Effects of Warm-up Intensity and Blood Flow Restriction: A Randomized Controlled Clinical Trial

Conditions
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Healthy Men

Intervention / Treatment
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* Other: Warm-up exercise
* Other: Warm-up exercise with Blood Flow Restriction


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: male healthy amateur soccer player aged between 18 and 35 years Exclusion Criteria: smokers; alcoholics; use drugs that influenced cardiac autonomic activity; cardiovascular, metabolic or endocrine diseases; having one or more predisposing risk factors for thromboembolism; history of lower extremity surgery or musculoskeletal injury within the last six months that may impair your performance during testing or warm-up (e.g., meniscal repair, ligament reconstruction, muscle injury, tendinopathy, lower extremity patellofemoral pain, and/or back pain);

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 35 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: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: warm-up performed at 30% VO2max<br>The warm-up exercise will be performed on an ergometric treadmill, through a protocol of 15 minutes duration, with the first 5 minutes of acceleration, until reaching 30% of VO2max, the following 5 minutes of maintenance and the remaining 5 minutes being of slowdown. | Other: Warm-up exercise<br>* The warm-up exercise will be performed on a treadmill.<br>* Other names: Aerobic Exercise;|
| Experimental: warm-up performed at 80% VO2max<br>The warm-up exercise will be performed on an ergometric treadmill, through a protocol of 15 minutes duration, with the first 5 minutes of acceleration, until reaching 80% of VO2max, the following 5 minutes of maintenance and the remaining 5 minutes being of slowdown. | Other: Warm-up exercise<br>* The warm-up exercise will be performed on a treadmill.<br>* Other names: Aerobic Exercise;|
| Experimental: warm-up performed at 30% VO2max with Blood Flow Restriction<br>The warm-up exercise will be performed on an ergometric treadmill, through a protocol of 15 minutes of duration, with the first 5 minutes of acceleration, until reaching 30% of VO2max, the following 5 minutes of maintenance and the remaining 5 minutes being of slowdown. During the warm-up exercise, a pressure cuff will be used on each leg, with the blood flow restriction technique (80% of arterial occlusion pressure). | Other: Warm-up exercise with Blood Flow Restriction<br>* The warm-up exercise will be performed on a treadmill and pressure cuffs will be used for the blood flow restriction technique.<br>* Other names: Blood Flow Restriction;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Temperature | Skin surface temperature will be evaluated using a thermographic camera | At the baseline | 
| Temperature | Skin surface temperature will be evaluated using a thermographic camera | Immediately after warm-up | 
| Performance in Squat Jump Test | The squat jump test will be performed at jumping platform (Multisprint, Hidrofit, Brazil) | At the baseline | 
| Performance in Squat Jump Test | The squat jump test will be performed at jumping platform (Multisprint, Hidrofit, Brazil) | Immediately after warm-up | 
| Performance in 30 meter sprint | the sprint test will be performed in a hall and two pairs of photoelectric cells (Multisprint®, Hidrofit, Brazil) will be used with an accuracy of 0.01 seconds. | At the baseline | 
| Performance in 30 meter sprint | the sprint test will be performed in a hall and two pairs of photoelectric cells (Multisprint®, Hidrofit, Brazil) will be used with an accuracy of 0.01 seconds. | Immediately after warm-up | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain threshold | To assess the pain threshold, the pressure algometer will be applied at 10 specific locations on the lower limb | At the baseline | 
| Pain threshold | To assess the pain threshold, the pressure algometer will be applied at 10 specific locations on the lower limb | Immediately after warm-up | 
| Muscle Pain | The subjective evaluation of pain will be obtained through the Visual Analogue Scale (VAS), graded from 0 to 10, with zero being the total absence of pain and 10 the maximum level of pain supported by the participan | At the baseline | 
| Muscle Pain | The subjective evaluation of pain will be obtained through the Visual Analogue Scale (VAS), graded from 0 to 10, with zero being the total absence of pain and 10 the maximum level of pain supported by the participan | Immediately after warm-up | 
| Perceived Effort Scale (Borg) | The degree of subjective exertion reported by the participants in relation to the lower limbs will be analyzed by Borg's scale of perception of effort of 0 to 10 points, 0 being very easy and 10 being exhaustive. | At the baseline and Immediately after warm-up | 
| Perceived discomfort Scale (Likert-RFS) | The degree of subjective discomfort reported by the participants in relation to the lower limbs refferd a blood flow restriction will be analyzed by Likert Scale of perception of effort of 0 to 10 points, 0 being no discomfort and 10 being very discomfortable. | At the baseline and Immediately after warm-up | 
| Resistance through Bioimpedance analysis (BIA) | Evaluation of tissue resistance, the higher the value, the worse the result | At the baseline and Immediately after warm-up | 
| Reactance through Bioimpedance analysis (BIA) | Evaluation of tissue reactance, the higher the value, the better the cell integrity | At the baseline and Immediately after warm-up | 
| Phase angle through Bioimpedance analysis (BIA) | Assessment of the phase angle, the higher the value, the better the condition of the participant | At the baseline and Immediately after warm-up | 
| Tone muscular through Myotonometry used the MyotonPRO equipment | Natural Oscillation Frequency [Hz], characterizing Tone of the muscles: quadriceps femoris, biceps femoris, semitendinosus, triceps surae and tibialis anterior | At the baseline and Immediately after warm-up | 
| Stiffness through Myotonometry used the MyotonPRO equipment | Mechanical Stress Relaxation Time [ms] featuring muscle elasticity of the muscles: quadriceps femoris, biceps femoris, semitendinosus, triceps surae and tibialis anterior | At the baseline and Immediately after warm-up | 
| heart rate variability indices in the time domain | Mean RR, SDNN e rMSSD | At the baseline time (30 minutes rest in the supine position), during the warm-up (15 minutes in the treadmill) and immediately after the warm-up (60 minutes rest in the supine position) | 
| heart rate variability indices in the frequency domain | LF and HF in nu and ms2 | At the baseline time (30 minutes rest in the supine position), during the warm-up (15 minutes in the treadmill) and immediately after the warm-up (60 minutes rest in the supine position) | 
| heart rate variability indices analyzed in the Poincaré plot | SD1 and SD2 in ms | At the baseline time (30 minutes rest in the supine position), during the warm-up (15 minutes in the treadmill) and immediately after the warm-up (60 minutes rest in the supine position) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Vascular occlusion, Performance, Body temperature, warm-up