Muscle Damage and Immune-Endocrine Responses in 20-km Walking Race

The objective of the study was to monitor exercise-induced muscle damage (EIMD), inflammatory responses (IL-6, TNFα, and IL-10), and immune-endocrine balance (testosterone, cortisol, and salivary SIgA) in official 20 km walking race competitions. Eight 20 km professional walking racers (n = 6 women), 27 ± 9 years, underwent blood and saliva sampling, evaluation of delayed-onset muscle soreness (DOMS), and squat (SJ) and countermovement (CMJ) jump tests 2 h before (Pre), immediately after (Post), and 24 and 48 h after the competition. The rate of perceived exertion (RPE) was recorded 20 minutes after the race ended. The race evoked high competitive load (948.3 ± 268.0 a.u.), increased creatine kinase levels at 24 h (p < 0.05), and DOMS at 48 h (p < 0.05), but no significant changes in SJ and CMJ after the race. No significant changes in cytokines were detected. No changes in salivary SIgA secretion rate and inflammatory cytokines were detected (p > 0.05). The race induced increased testosterone (p < 0.05), and cortisol (p < 0.01) levels immediately after the race. Despite the high competitive load, 20-km walking racer athletes presented mild EIMD without impairment in immune-endocrine markers.