title: Yo-Yo IR2 testing of elite and sub-elite soccer players: performance, heart rate response and correlations to other interval tests.
abstract: We examined performance, heart rate response and construct validity of the Yo-Yo IR2 test by testing 111 elite and 92 sub-elite soccer players from Norway and Denmark. VO₂max, Yo-Yo IR1 and repeated sprint tests (RSA) (n = 51) and match-analyses (n = 39) were also performed. Yo-Yo IR2 and Yo-Yo IR1 performance was 41 and 25% better (P < 0.01) for elite than sub-elite players, respectively, and heart rate after 2 and 4 min of the Yo-Yo IR2 test was 20 and 15 bpm (9 and 6% HRmax), respectively, lower (P < 0.01) for elite players. RSA performance and VO₂max was not different between competitive levels (P > 0.05). For top-teams, Yo-Yo IR2 performance (28%) and sprinting distance (25%) during match were greater (P < 0.05) than for bottom-teams. For elite and sub-elite players, Yo-Yo IR2 performance was correlated (P < 0.05) with Yo-Yo IR1 performance (r = 0.74 and 0.76) and mean RSA time (r = -0.74 and -0.34). We conclude that the Yo-Yo IR2 test has a high discriminant and concurrent validity, as it discriminates between players of different within- and between-league competitive levels and is correlated to other frequently used intermittent elite soccer tests.
authors.affiliation: Centre of Practical Knowledge, Department of Sports, University of Nordland, Bodø, Norway. jorgen.ingebrigtsen@uin.no
authors.forename: Jørgen
authors.initials: J
authors.lastname: Ingebrigtsen
authors.forename: Mads
authors.initials: M
authors.lastname: Bendiksen
authors.forename: Morten Bredsgaard
authors.initials: MB
authors.lastname: Randers
authors.forename: Carlo
authors.initials: C
authors.lastname: Castagna
authors.forename: Peter
authors.initials: P
authors.lastname: Krustrup
authors.forename: Andreas
authors.initials: A
authors.lastname: Holtermann
mesh_terms: D000293:Adolescent; D000328:Adult; D054874:Athletic Performance / Q000502:physiology*; D003718:Denmark; D005080:Exercise Test / Q000592:standards*; D006339:Heart Rate; D006801:Humans; D009664:Norway; D010101:Oxygen Consumption; D010807:Physical Endurance / Q000502:physiology*; D012420:Running / Q000502:physiology*; D012916:Soccer / Q000502:physiology*; D055815:Young Adult