title: Validity and reliability of the 45-15 test for aerobic fitness in young soccer players.
abstract: The aim of this study was to examine the reliability and validity of a popular field test for aerobic fitness used in soccer (45-15) in Italy. Alternating progressive 45-s runs with 15 s passive recovery until exhaustion, the test considers peak speed (PS) as a reflection of maximal aerobic speed (MAS). The validity and reliability of the 45-15 was assessed in 18 young male soccer players (age 16.7 ± 1.8 y, body mass 70 ± 7.45 kg, height 177 ± 0.5 cm, 55.62 ± 5.56 mL · kg-1 ·min-1) submitted to laboratory testing for aerobic fitness and repeatedly to the 45-15. Results showed that 45-15 PS was significantly related to VO2max (r = .80, P < .001, 95%CI .47-.93) and MAS (r = .78, P = .001, 95%CI .43-.93). No significant bias between MAS 45-15 PS (P = .11) was found during the measurement-consistency study. Receiver-operating-characteristic (ROC) analysis showed that 45-15 PS was sensitive in detecting VO2max changes in subjects as revealed by area under the curve (.97; 95%CI .73-1). Players with peak 45-15 speed equal to or above 16.5 km/h (ie, ROC cutoff) may be considered to have good aerobic fitness. In light of this study's findings, the 45-15 test may be considered a reliable and valid test to evaluate meaningful information to direct generic aerobic training in soccer.
authors.affiliation: Football Training and Biomechanics Laboratory, Italian Football Federation (FIGC), Coverciano (Florence), Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Castagna
authors.forename: Ferdinando
authors.initials: F
authors.lastname: Iellamo
authors.forename: Franco Maria
authors.initials: FM
authors.lastname: Impellizzeri
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Manzi
mesh_terms: D000293:Adolescent; D000367:Age Factors; D015415:Biomarkers / Q000097:blood; D005080:Exercise Test / Q000379:methods*; D006339:Heart Rate; D006801:Humans; D007558:Italy; D019344:Lactic Acid / Q000097:blood; D008297:Male; D009119:Muscle Contraction; D018763:Muscle Fatigue; D018482:Muscle, Skeletal / Q000378:metabolism*; D010101:Oxygen Consumption; D010809:Physical Fitness; D011237:Predictive Value of Tests; D012372:ROC Curve; D020127:Recovery of Function; D015203:Reproducibility of Results; D012420:Running; D012916:Soccer; D013997:Time Factors
chemical_list: D015415:Biomarkers; D019344:Lactic Acid