Reliability, Usefulness, and Validity of the 30–15 Intermittent Ice Test in Young Elite Ice Hockey Players

Abstract

The purpose of this study was to examine the reliability, usefulness, and validity of the 30-15 Intermittent Ice Test (30-15(IIT)) in 17 young elite ice hockey players. For the reliability and usefulness study, players performed the 30-15(IIT) 7 days apart. For the validity study, data derived from the first 30-15(IIT) were compared with those obtained from the 30-15 Intermittent Fitness Test (30-15(IFT), the running version of this test used as a reference marker for its ability to assess cardiovascular fitness in the field, that is, VO₂peak). Maximal speed, heart rate at exhaustion (HR(peak)) and postexercise blood-lactate levels ([La](b)) were collected for all tests, whereas submaximal HR was taken at stages 4 and 8 (HR(stage4) and HR(stage8)) during the 30-15(IIT). All intra-class correlation coefficients were >0.94. Coefficients of variation were 1.6% (90% CI, 1.3-2.3), 1.7% (1.3-2.8), 1.4% (1.0-2.2), and 0.7% (0.5-1.1) for maximal skating speed, HR(stage4), HR(stage8), and HR(peak), respectively. Correlations between maximal velocities and HR(peak) obtained for the 30-15(IIT) vs. 30-15(IFT) were very large (r = 0.72) and large (r = 0.61), respectively. Maximal skating speed was also largely correlated to estimated VO₂peak (r = 0.71). There was however no correlation for [La](b) values between both tests (r = 0.42). These results highlight the specificity of the on-ice 30-15(IIT) and show it to be a reliable and valid test for assessing cardiorespiratory fitness in young elite players. Coaches could interpret a change in performance of at least 2 stages, or a change in submaximal HR of more than 8% (≈8 b·min⁻¹) during the eighth stage to be a meaningful change in skating fitness.