title: Between-Days Reliability and Sensitivity of Common Fatigue Measures in Rugby Players.
abstract: This study established the between-days reliability and sensitivity of a countermovement jump (CMJ), plyometric push-up, well-being questionnaire, and whole-blood creatine kinase concentration ([CK]) in elite male youth rugby union players. The study also established the between-days reliability of 1, 2, or 3 CMJs and plyometric-push-up attempts. Twenty-five players completed tests on 2 occasions separated by 5 d (of rest). Between-days typical error, coefficient of variation (CV), and smallest worthwhile change (SWC) were calculated for the well-being questionnaire, [CK], and CMJ and plyometric-push-up metrics (peak/mean power, peak/mean force, height, flight time, and flight-time to contraction-time ratio) for 1 maximal effort or taking the highest score from 2 or 3 maximal efforts. The results suggest that CMJ mean power (2 or 3 attempts), peak force, or mean force and plyometric-push-up mean force (from 2 or 3 attempts) should be used for assessing lower- and upper-body neuromuscular function, respectively, due to both their acceptable reliability (CV < 5%) and good sensitivity (CV < SWC). The well-being questionnaire and [CK] demonstrated between-days CVs >5% (7.1% and 26.1%, respectively) and poor sensitivity (CV > SWC). The findings from this study can be used when interpreting fatigue markers to make an objective decision about a player's readiness to train or compete.
authors.affiliation: Inst for Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, West Yorkshire, UK.
authors.forename: Gregory
authors.initials: G
authors.lastname: Roe
authors.forename: Joshua
authors.initials: J
authors.lastname: Darrall-Jones
authors.forename: Kevin
authors.initials: K
authors.lastname: Till
authors.forename: Padraic
authors.initials: P
authors.lastname: Phibbs
authors.forename: Dale
authors.initials: D
authors.lastname: Read
authors.forename: Jonathon
authors.initials: J
authors.lastname: Weakley
authors.forename: Ben
authors.initials: B
authors.lastname: Jones
mesh_terms: D056352:Athletes; D015415:Biomarkers; D003402:Creatine Kinase / Q000097:blood; D005080:Exercise Test; D005538:Football; D006801:Humans; D008297:Male; D018763:Muscle Fatigue; D059385:Plyometric Exercise; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires
chemical_list: D015415:Biomarkers; D003402:Creatine Kinase