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Molecular and Physiological Adaptations to Seasonal Training in Elite U18 Ice Hockey Players
Attila Czont1,2, Zsolt Bodor2, Tamás Koncsag1,2
1Faculty of Science, University of Pecs, Ifjusag 6, H-7624 Pecs, Hungary.
Abstract:
Monitoring adolescent team-sport athletes may benefit from combining performance and molecular markers, but empirical evidence supporting this approach in youth team sports remains limited.
Objective:
Our study investigated molecular and physiological adaptations to seasonal training in elite U18 ice hockey players, focusing on aerobic capacity, salivary cortisol, serum irisin, and cell-free DNA (cfDNA) dynamics.
Methods:
National-level U18 players were enrolled in our study (n = 23 for cross-sectional analysis, n = 12 longitudinal) during the pre- and early-competition season. Aerobic performance was assessed via graded treadmill VO2max testing, and the biochemical markers quantified using ELISA-based assays.
Results:
From pre- to early-season (paired n = 12), VO2max increased by 10.6% (g = +1.00, p = 0.003) and irisin by 14.7% (g = +0.83, p = 0.010). cfDNA decreased by 60.8% (g = -0.54, p = 0.070; moderate effect, not statistically clear), while cortisol remained stable (+11.3%; p = 0.667). Inter-individual variability increased for VO2max and irisin and decreased by 82% for cfDNA. Exploratory cross-sectional positional analysis indicated higher irisin levels in forwards and elevated cfDNA in defensemen, although differences did not reach statistical significance.
Conclusions:
These preliminary findings provide cohort-size limited longitudinal evidence of chronic irisin elevation in ice hockey players and highlight the possibility of combining VO2max + irisin + cfDNA to assist individualized load/recovery in elite youth ice hockey.
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