The Effects of Fatigue on Exercise-Induced Hypoalgesia During a Dynamic Resistance Exercise

Study Overview
=================
Brief Summary
-----------------
The primary purpose of this study is to compare immediate changes in pain sensitivity (pressure pain threshold) during quiet rest, low fatigue exercise, and high fatigue exercise.

Detailed Description
-----------------
Participants will attend three sessions. Participants will fill out questionnaires, undergo pain sensitivity testing, and be randomly assigned to complete a high and low fatigue exercise on either the second or third session. During the exercise, participants will complete three sets of a single leg knee extension exercise with weight equivalent to 50% of their 1 repetition maximum until they report either a high or low fatigue level. Immediately before and after each set, the research team will examine immediate changes in sensitivity to pressure (pressure pain threshold).

Official Title
-----------------
The Effects of Fatigue on Exercise-Induced Hypoalgesia During a Dynamic Resistance Exercise

Conditions
-----------------
Healthy

Intervention / Treatment
-----------------
* Other: Knee Extension Exercise
* Other: Quiet Rest


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Pain-free 18-60 years old Participant can appropriately perform the knee extension exercise (assessed during screening) Exclusion Criteria: Non-English speaking Regular use of prescription pain medications Current or history of chronic pain condition Currently taking blood-thinning medication Systemic medical condition known to affect sensation, such as uncontrolled diabetes or neurological conditions Any contraindication to the application of ice, such as: uncontrolled hypertension (blood pressure over 140/90 mmHg), cold urticaria, cryoglobulinemia, paroxysmal cold hemoglobinuria, circulatory compromise Known presence of cardiovascular, pulmonary, or metabolic disease Current use of tobacco products Not physically ready to exercise without a medical exam as indicated by the Physical Activity Readiness Questionnaire Plus (PAR-Q+) Surgery, injury, or fracture to the lower back or lower extremity within the past 6 months

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

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Low Fatigue Exercise<br>Participants will complete a single leg knee extension exercise with weight until they report a fatigue level = 3/10 on the Borg Rating of Perceived Exertion. Participants will complete three sets. | Other: Knee Extension Exercise<br>* Participants will be seated in a Steel Flex machine with weight equal to 50% of their 1 repetition maximum added to the machine. Participants will extend the dominant knee until the assigned fatigue level.<br>|
| Experimental: High Fatigue Exercise<br>Participants will complete a single leg knee extension exercise with weight until they report a fatigue level = 8/10 on the Borg Rating of Perceived Exertion. Participants will complete three sets. | Other: Knee Extension Exercise<br>* Participants will be seated in a Steel Flex machine with weight equal to 50% of their 1 repetition maximum added to the machine. Participants will extend the dominant knee until the assigned fatigue level.<br>|
| Active Comparator: Quiet Rest<br>Participants will rest quietly for two minutes, three sets. | Other: Quiet Rest<br>* Participants will sit quietly for two minutes, three times.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Pressure Pain Threshold | A digital pressure algometer will be applied to the quadriceps and upper trapezius for two trials each. Participants are instructed to say stop or pain so the stimulus can be terminated when the sensation first transitions from pressure to pain (pain threshold). Participants will rate the pain experienced during the threshold testing using a 101-point numeric pain rate scale (NPRS) anchored with 0= no pain to 100= the most intense pain sensation imaginable immediately following each testing time. | Change from baseline immediately after exercise | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Temporal Summation | Participants will rate a train of 10 heat pulses using the 101-point numerical pain rating scale | Baseline, pre exercise | 
| Heat Pain Threshold | A thermode will gradually increase temperature. Participants will state when the sensation first becomes painful. | Baseline, pre exercise | 
| Conditioned Pain Modulation | Pressure pain threshold after an ice water immersion task will be measured. | Baseline, pre exercise | 
| International Physical Activity Questionnaire Short Form | This is a self-report measure of physical activity that provides data regarding health-related physical activity. | Baseline, pre exercise | 
| Pittsburgh Sleep Quality Index | This is a 10-item questionnaire in which individuals respond to statements regarding sleep quality. A higher score indicates a worse sleep quality. | Baseline, pre exercise | 
| Pain Catastrophizing Scale | This is a 13-item questionnaire in which individuals respond to a statement on a five point scale from 0 to 4. Higher scores indicate higher pain catastrophizing levels. | Baseline, pre exercise | 
| Fear of Pain Questionnaire 9 | This is a 9-item questionnaire in which individuals respond to a statement on a five point scale from 1 to 5. Higher scores indicate higher fear of pain. | Baseline, pre exercise | 
| Pain Anxiety Symptom Scale | This is a 20-item questionnaire in which individuals respond to a statement on a six point scale from 0 to 5. Higher scores indicate higher pain-related anxiety. | Baseline, pre exercise | 
| Brief Resilience Scale | This is a 6-item questionnaire in which individuals respond to a statement on a five point scale from 1 to 5. Higher scores indicate greater resilience. | Baseline, pre exercise | 
| Preference for and Tolerance of the Intensity of Exercise Questionnaire | This is a 16-item questionnaire in which individuals respond to a statement on a five point scale from 1 to 5. Higher scores indicate lower tolerance for the intensity of exercise. | Baseline, pre exercise |