Comparative analysis of plasma irisin levels post- resistance workouts: a preliminary study

This preliminary investigation compared acute plasma irisin responses to two resistance-training protocols of differing eccentric emphasis in seven trained young men. Participants performed high-volume sessions either to exhaustion with a slow eccentric phase (Session A) or with two repetitions in reserve and reduced eccentric load (Session B). Blood samples collected at baseline, 24 h, and 48 h post-exercise revealed no significant irisin change after Session A, whereas Session B elicited a delayed rise between 24 h and 48 h. Creatine kinase and perceived exertion increased after both sessions, with higher peaks following Session A. These findings suggest that reduced-eccentric resistance exercise may favour a late irisin response, warranting further research with larger cohorts and extended sampling.