# Reference Data by Player Position for an Ice Hockey-Specific Complex Test
## 4 Discussion  
This study aimed to provide position-specific reference data for reliable and valid ice hockey-specific complex test (IHCT). The differentiation of the field players as defenders and forwards revealed a significant difference in weave agility with a puck (\(p<0.001\), \(\eta_{\text{p}}^{2}=0.122\), d = 0.76) in favor of the forwards. Clear but insignificant (level of significance: \(p<0.002\)) differences were also found in weave agility without a puck (\(p=0.008\)), 30 m backward sprinting without a puck (\(p=0.012\)) and goals after test (\(p=0.030\)). For the anthropometric parameters, there was only a weak significant between-group difference (\(p=0.006\), \(\eta_{\text{p}}^{2}=0.071\)) in height. Again, the forwards (1.81 \(\pm\) 0.06 m) displayed a lower height compared to defenders (1.84 \(\pm\) 0.06 m). The findings from this investigation partially confirm the hypothesis that different field positions have different ice hockey-specific performance requirements. More specifically, forwards had the fastest forward skating performance without/with a puck and the highest level of skating skills with direction changes, but the performance levels were not significantly different. As expected, defenders showed small advantages for backward skating and shot velocity, but only with the slap shot. In this respect, these results reflect the differences required by the position. This discussion must be preceded by the fact that there is no reference data for evaluated (validity and reliability) ice hockey-specific complex tests. Numerous ice hockey-related studies have investigated isolated performance test parameters based on playing position [4, 9, 11, 12, 16, 24, 25, 26, 27, 28, 29, 30, 31]. However, these studies' comparability is limited due to differences in test designs (e.g., sample size, age, gender, performance level, on-ice vs. off-ice tests, match performance vs. test performance). The need for a complex on-ice diagnostic has been supported by the studies of [PERSON] et al. [32] and [PERSON] et al. [9]. Both investigations showed that the specific technique (skating vs. running) [32] and the specific environment (off-ice vs. on-ice) [9] are critical factors for the functionality of the test results with regards to the prediction of the match performance. Similar to the findings of [PERSON] et al. [10], the results of this study support and highlight the importance of ice-hockey-specific testing, ideally using position-specific reference data. Only [PERSON] et al. [15] investigated a comparable sample (n = 120 vs. n = 104) of male ice hockey players. Our sample showed a similar position distribution (62% forwards) to those of [PERSON] et al. [15] (66% forwards). Goalkeepers were also excluded from their study. However, the performance was quite different between these studies, potentially because [PERSON] et al. [15] only captured off-ice parameters as surrogate parameters for lower- (vertical jump) and upper-body (bench press) power and strength. The aim of the study from [PERSON] et al. [15] was to judge the relationship between match performance by using points scored, comparable with [PERSON] et al. [10], and the above off-ice parameters. In contrast, [PERSON] et al. [5] investigated a much smaller (n = 18) and younger (aged 13-14 years old) population and only included forwards, but with a similar test design regarding the complexity of the performance diagnostic (on-ice and off-ice tests). The on-ice performance also included five skating tests: forward speed skating, backward speed skating, skating agility with a puck, skating agility without a puck, and a skating anaerobic power test. Additionally, and in contrast to the present study, the authors conducted some off-ice tests: push-ups, sit-ups, burpees, and treadmill tests. The authors chose a longitudinal approach (three sessions during the season) and found significant improvements in all skating performance tests during the hockey season. [PERSON] et al.