## 4 Discussion  
To the best of our knowledge, this is the first study to examine and compare physical test results of an advanced, validated team handball game-based performance test and the widely used Yo-Yo IR test [34] as well as the SSPT for elite team handball players. As main findings, the GBPT was shown to be better than the Yo-Yo IR1 test to evaluate female adult top-elite field team handball players' ability to perform physical match-related activities including both locomotive and technical playing actions executed as during competitive match-play. In addition, no significant differences between the various playing positions were found either for the GBPT, the SSPT and the Yo-Yo IR1 test. **Yo-Yo intermittent recovery test (level 1)**  
To evaluate the validity of the Yo-Yo IR1 test in team handball, the optimal study procedure will be to compare the Yo-Yo IR1 test performance with physical match activities  
Figure 2: Linear regression analysis plots between (**A**) the total running distance covered in the Yo-Yo intermittent recovery test, level 1 (Yo-Yo IR1) and peak oxygen uptake in the team handball game-based performance test (GBPT), between (**B**) the HR in the Yo-Yo IR1 and HR in the GBPT, between (**C**) sprint time in the 30-m single sprint performance test (SSPT) and defence time in the GBPT as well as between (**D**) the total running distance covered in the Yo-Yo IR1 and the fast retreat time in the GBPT. (performance) during team handball competitive match-play [34]. Only one study has previously tried to do this [35]. However, the study participants were young male non-elite players (aged 14 years) examined during 50 min experimental matches with special rules. In addition, the total running distance covered during match-play was remarkable low, and no significant relationships were found between Yo-Yo IR1 test performance and high-intensity match activities. The latter findings are challenged by numerous studies showing much higher total match running distance covered and in particular by the conclusion that high-intensity activities are crucial for the performance of adult elite field team handball players during competitive match-play [1; 11; 14; 22; 36]. The GBPT has been validated for experienced male team handball players [10]. However, the present study wanted to examine the physical performance of female adult top-elite field team handball players. As a consequence, it was not possible to include real team handball matches in the investigation. The study took place during the beginning of the last part of the preparation phase, i.e., in the end of July after the summer break. At this time, there are no competitive matches for professional clubs. Additionally, the clubs were not interested to play friendly games against high-level opponents, and colleagues, from the Danish Premier Female Team Handball League at this particular time during their early preparations for the up-coming season. Furthermore, to change their training schedule and spend two training days on the present study was enough for them. Thus, it was not possible to examine the direct validity of the Yo-Yo IR1 test in female adult top-elite field team handball players. Consequently, in the present study, we analysed the relationship between the more complex team handball GBPT and the more practical Yo-Yo IR1 test, as well as the SSPT, the most frequently used physical performance tests in team handball. In a previous study, the GBPT was found to be very well suited to measure team handball match-related activities, since it closely mirrors the physical performance during actual team handball match-play [10]. The percentage of the various exercise intensities was almost similar in the two cases, and similar to real team handball match-play the GBPT also contains technical playing actions such as jumping and shooting with a ball, specific movement patterns in offence and defence, multiple changing of directions and tackles.