title: Yo-Yo Intermittent Recovery Test Level 2 and Its Relationship With Other Typical Soccer Field Tests in Female Collegiate Soccer Players.
abstract: The ability to complete high-intensity running is essential for soccer. The Yo-Yo Intermittent Recovery Test Level 2 (YYIRT2) can measure this capacity, but there is limited information regarding this assessment in collegiate female soccer players. This study investigated the YYIRT2 as a measure of high-intensity running in this population, and its relationship to other soccer field tests. Twenty-one players from a Division I team were recruited. In addition to the YYIRT2, subjects completed linear (0-5, 0-10, and 0-30 m sprint intervals) and change-of-direction (pro-agility and 60-yard shuttle) speed tests, as well as the YYIRT Level 1 (YYIRT1), to assess relationships with YYIRT2 by correlations (p ≤ 0.05). The correlation of YYIRT1 with the speed tests was also assessed. The YYIRT1 and YYIRT2 were standardized using z-scores for comparison with elite benchmarks to investigate relative performance on each test. The YYIRT2 and YYIRT1 distances did not significantly correlate with those of the speed tests (r = -0.251 to 0.274). There was a large relationship between YYIRT2 and YYIRT1 distances (r = 0.582), although the explained variance was low (33.87%). Mean YYIRT2 z-scores (-4.29 ± 1.66) indicated a performance further from elite benchmarks than those of the YYIRT1 (-1.92 ± 1.61), and 90.5% (19 of 21) subjects performed relatively better in the YYIRT1 than YYIRT2. The YYIRT2 provided a more specific measure of high-intensity running to that of the YYIRT1 in collegiate female soccer players. Coaches may consider using the YYIRT2 to gauge and track progress of high-intensity running capabilities and create training programs to improve this ability in female players.
authors.affiliation: 1Department of Kinesiology, California State University, Fullerton, Fullerton, California; 2Department of Kinesiology, California State University, Northridge, Northridge, Los Angeles, California; and 3Center for Exercise and Sports Science Research, School of Medical and Health Sciences, Edith Cowan University, Joondalup, Australia.
authors.forename: Robert G
authors.initials: RG
authors.lastname: Lockie
authors.forename: Farzad
authors.initials: F
authors.lastname: Jalilvand
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Moreno
authors.forename: Ashley J
authors.initials: AJ
authors.lastname: Orjalo
authors.forename: Fabrice G
authors.initials: FG
authors.lastname: Risso
authors.forename: Sophia
authors.initials: S
authors.lastname: Nimphius
mesh_terms: D054874:Athletic Performance / Q000502:physiology*; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006801:Humans; D012015:Reference Standards; D012420:Running / Q000502:physiology*; D012916:Soccer / Q000502:physiology*; D014495:Universities; D055815:Young Adult