Muscle soreness, swelling, stiffness and strength loss after intense eccentric exercise

Area of Science:

• Exercise Physiology
• Sports Medicine
• Muscle Physiology

Background:

• High-intensity eccentric contractions are known to cause muscle damage, leading to performance decrements and delayed onset muscle soreness.
• Understanding the time course and interrelationships of these effects is crucial for effective rehabilitation strategies.

Purpose of the Study:

• To investigate the magnitude and time course of performance decrements and delayed onset muscle soreness following maximal eccentric contractions.
• To examine the interrelationships between soreness, swelling, joint angle, and isometric strength.

Main Methods:

• Twenty-six young women performed 70 maximal eccentric contractions of the elbow flexors.
• Measures of soreness, tenderness, swelling (SW), relaxed elbow joint angle (RANG), and isometric strength (STR) were recorded before exercise, immediately after, and for 11 days post-exercise.
• Analysis of variance (ANOVA) was used to assess significant changes.

Main Results:

• All measured variables showed significant changes (P < 0.01) post-exercise.
• Peak effects for most variables occurred between 24 and 96 hours after exercise (AE).
• Isometric strength (STR) remained significantly lower (P < 0.01) at 11 days AE, while other factors returned to baseline. Pain did not correlate significantly with strength loss.

Conclusions:

• Eccentric exercise induces prolonged strength deficits that persist even after pain and tenderness resolve, suggesting slow soft tissue repair.
• Strength loss is a key outcome, with implications for managing muscle injuries and guiding rehabilitation protocols.
• The lack of correlation between swelling, joint angle, and pain highlights the complex nature of muscle recovery post-eccentric exercise.