Mechanisms of Exercise-Induced Hypoalgesia

Study Overview
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Brief Summary
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Exercise-Induced Hypoalgesia (EIH) is a lessening of pain sensitivity in response to an acute bout of exercise. Limited research has examined the effects of expectations on EIH during a dynamic resistance training during different intensities. Therefore, the purpose of this study is to examine the effects of positive and negative expectations on EIH.

Detailed Description
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Individuals who meet the eligibility criteria and consent to participate will attend one testing session that is approximately one hour. Baseline Pressure Pain Threshold will be measured followed by random assignment to one of four study arms.

Official Title
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Mechanisms of Exercise-Induced Hypoalgesia

Conditions
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Healthy

Intervention / Treatment
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* Other: Positive Expectations Instructional Set
* Other: Negative Expectations Instructional Set


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Pain Free Exclusion Criteria: Non-English speaking Regular use of prescription pain medications Current or history of chronic pain condition Currently taking blood-thinning medication Any blood clotting disorder, such as hemophilia Systemic medical condition known to affect sensation, such as uncontrolled diabetes or neurological conditions Not physically ready to exercise without a medical exam as indicated by the Physical Activity Readiness Questionnaire Plus (PAR-Q+) Not have had Surgery, injury, or fracture within the past 6 months

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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All

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: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: High Intensity Exercise<br>Participants will complete an upper body resistance exercise until they report a high fatigue level. | Other: Positive Expectations Instructional Set<br>* Participants randomly assigned to this instructional set will be told, You will be completing an intervention known to be effective for some people with shoulder pain. We expect this will make you less sensitive to the pressure applied to your shoulder and thigh and you will require more pressure than what was previously necessary to experience pain.<br>Other: Negative Expectations Instructional Set<br>* Participants randomly assigned to this instructional set will be told, You will be completing an intervention which is not effective for some people with shoulder pain. We expect this will make you more sensitive to the pressure applied to your shoulder and thigh and you will require less pressure than what was previously necessary to experience pain.<br>|
| Experimental: Low Intensity Exercise<br>Participants will complete an upper body resistance exercise until they report a low fatigue level. | Other: Positive Expectations Instructional Set<br>* Participants randomly assigned to this instructional set will be told, You will be completing an intervention known to be effective for some people with shoulder pain. We expect this will make you less sensitive to the pressure applied to your shoulder and thigh and you will require more pressure than what was previously necessary to experience pain.<br>Other: Negative Expectations Instructional Set<br>* Participants randomly assigned to this instructional set will be told, You will be completing an intervention which is not effective for some people with shoulder pain. We expect this will make you more sensitive to the pressure applied to your shoulder and thigh and you will require less pressure than what was previously necessary to experience pain.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pressure Pain Threshold | Pressure Pain Threshold will be applied with a digital algometer before and after the exercise intervention. | Change from baseline immediately after exercise |