title: Markers of postmatch fatigue in professional Rugby League players.
abstract: The aim of the present study was to identify neuromuscular, biochemical, and endocrine markers of fatigue after Rugby League match play. Seventeen elite Rugby League players were monitored for a single match. Peak rate of force development (PRFD), peak power (PP), and peak force (PF) were measured during a countermovement jump (CMJ) on a force plate pre and postmatch play. Saliva and blood samples were collected 24 hours prematch, 30 minutes prematch, 30 minutes postmatch, and then at 24-hour intervals for a period of 120 hours to determine plasma creatine kinase concentration ([CK]) and salivary cortisol concentration ([sCort]). There were significant (p < 0.05) decreases in PRFD and PP up to 24 hours postmatch with PF significantly (p < 0.05) decreased immediately postmatch. The [sCort] significantly (p < 0.05) increased from 24 hours prematch to 30 minutes prematch and up to 24 hours postmatch compared with 24 hours prematch. Plasma [CK] significantly (p < 0.05) increased 30 minutes postmatch with a peak occurring 24 hours postmatch and remained elevated above 24 hours prematch for at least 120 hours postmatch. There were significant (p < 0.05) correlations between the increase in [CK] and reduction in PRFD 30 minutes postmatch and 24 hours postmatch. The [sCort] was significantly (p < 0.05) correlated with the reduction in PF 30 minutes postmatch. Results demonstrate that neuromuscular function is compromised for up to 48 hours after match play. Elevated [CK] despite 120-hour recovery indicate that damage to muscle tissue after Rugby League match play may persist for at least 5 days postmatch. Despite the prolonged presence of elevated [CK] postmatch, strength training 48 hours postmatch may have resulted in a compensatory increase in PRFD supporting the inclusion of strength training during the short-term postmatch recovery period.
authors: Faculty of Health Sciences and Medicine, Bond University, Gold Coast, Queensland, Australia. cmclella@bond.edu.au
authors: Christopher P
authors: CP
authors: McLellan
authors: Dale I
authors: DI
authors: Lovell
authors: Gregory C
authors: GC
authors: Gass
mesh_terms: D000293:Adolescent; D015415:Biomarkers / Q000097:blood; D003402:Creatine Kinase / Q000097:blood; D005538:Football / Q000502:physiology*; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis; D008297:Male; D018763:Muscle Fatigue / Q000502:physiology*; D055070:Resistance Training; D012463:Saliva / Q000737:chemistry; D055815:Young Adult
chemical_list: D015415:Biomarkers; D003402:Creatine Kinase; D006854:Hydrocortisone