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Changes in inflammatory mediators following eccentric exercise of the elbow flexors
Lisa Hirose1, Kazunori Nosaka, Michael Newton
1School of Human Sciences, and Consolidated Research Institute for Advanced Science and Medical Care, Waseda University, Japan.
Exercise Immunology Review
|January 7, 2005
Summary
Eccentric exercise causes muscle damage, but systemic cytokine release is minor. Repeated exercise leads to adaptation, with IL-10 potentially mediating reduced inflammation.
Area of Science:
- Exercise Physiology
- Sports Medicine
- Inflammation Research
Background:
- Eccentric exercise is known to induce muscle damage, soreness, and functional deficits.
- The systemic inflammatory response, particularly cytokine release, following eccentric exercise is not fully understood.
- Muscle adaptation to repeated bouts of exercise can alter the response to subsequent exercise sessions.
Purpose of the Study:
- To investigate plasma concentrations of inflammatory mediators, including cytokines, after single and repeated bouts of eccentric exercise.
- To compare the extent of muscle damage, soreness, swelling, and functional changes between the first and second exercise bouts.
- To explore the role of specific cytokines, such as IL-10, in muscle adaptation to eccentric exercise.
Main Methods:
- Ten untrained males performed two bouts of eccentric elbow flexor exercise (6 sets x 5 reps) separated by four weeks.
- Muscle soreness, swelling, and function were assessed.
- Blood samples were collected pre- and post-exercise (up to 96 hours) to measure plasma creatine kinase (CK), myoglobin (Mb), and various cytokines (IL-1β, IL-1ra, IL-4, IL-6, IL-8, IL-10, IL-12p40, TNF-α, G-CSF), MPO, PGE2, and HSPs.
Main Results:
- The first eccentric exercise bout induced significant muscle soreness, swelling, decreased function, and increased plasma CK and Mb.
- These markers of muscle damage were significantly reduced after the second bout, indicating muscle adaptation.
- Despite muscle damage, changes in most plasma cytokines were minor and smaller than those seen after endurance exercise; notable changes included a transient increase in G-CSF and decreases in TNF-α and IL-8 after the first bout, and an increase in IL-10 after the second bout.
Conclusions:
- Eccentric exercise-induced muscle damage is not associated with substantial systemic cytokine release.
- Minor changes in systemic cytokine concentrations may be due to rapid clearance or low metabolic demand.
- The anti-inflammatory cytokine IL-10 may play a role in the adaptive response to repeated eccentric exercise-induced muscle damage.