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

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

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.

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).

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