## 4 Discussion
Average vertical jump heights for this study, other than for pre season first-years, were higher than reported for elite (40.3 \(\pm\) 6.0 cm) and county (36.6 \(\pm\) 4.2 cm) field hockey players in England [4]. Further, all class-year average vertical jump heights in this study were higher than regional 35 \(\pm\) 1 cm and club 29 \(\pm\) 1 cm female field hockey players in New Zealand [5]. [PERSON] et al. attributed the higher vertical jump in regional players to a higher level of lower body muscle power and an indicator of better play in field hockey [5]. The difference between the current athletes and past field hockey studies may be attributed to the methods used for the vertical jump. The prior studies did not use a countermovement jump, nor did they allow participants to swing their arms, which has been shown to result in higher vertical jump heights [35; 36]. Field hockey players, both in this study and prior studies, had a lower reported vertical jump height than Division I soccer players [10; 11; 18]. Although soccer and field hockey require similar fitness levels, soccer requires jumping throughout games, whereas field hockey does not. This necessary game skill may be the reason for the differences in the jump heights between the two sports. Due to the number of improvements in vertical jump seen in the current study, this may indicate that the team's ability, specifically with regards to explosive quick movements, improved during the competitive season. The Yo-Yo IR1 results conform to the hypothesis first-year athletes would have the lowest distance, and Yo-Yo IR1 distance would improve from pre to post season. The Yo-Yo IR1 distances by athletes in this study tended to fit within the context of other published studies of female field hockey players. Yo-Yo IR1 distances have shown to increase with both age and competition level [26]. Yo-Yo IR1 distances of sub-elite players in Australia were found to be 840 \(\pm\) 280 m for under 21 athletes (19.4 \(\pm\) 0.7 years) [37] and to increase to 1320 \(\pm\) 353 m for athletes aged 22.3 \(\pm\) 2.3 years [38]. Yo-Yo IR1 distances of elite players in Canada ranged from 1068 \(\pm\) 220 m for under 17 athletes and increased to 1480 \(\pm\) 332 m for under 21 athletes [28]. Using consistent athlete level classifications from [PERSON] et al., athletes in this study would fall at the amateur level, just below the sub-elite level [39]. Thus, the first-year athletes in this study having an average Yo-Yo IR1 distance lower than previous studies is reasonable. Further, the sophomore and junior athletes in this study having a higher Yo-Yo IR1 distance than the younger elite athletes, but lower than older sub-elite and comparably aged elite athletes was also expected. The average pre to post season gain of 19.7% for the current study is similar to the range of 12-28% improvement in Yo-Yo IR1 distances from multiple studies [26]. The large difference between the first-year average and the older athletes in this and previous studies indicates additional training or conditioning may be needed to bring new players to a higher level of fitness. The Yo-Yo IR1 test may be useful for coaches to determine if players are ready for the competitive season. First-year, sophomore, and junior athletes each received similar suggested summer workout routines. Sophomore and junior athletes also had previous collegiate level athletic training from spring; however, first-year athletes were not part of a collegiate level athletic training program prior to the beginning of fall pre season practice. The presence of a collegiate level spring training may explain the difference of Yo-Yo IR 1 distance for sophomore and junior athletes when compared to first-years. Future work examining longitudinal athlete development across the spring could account for these differences. The largest gains in all measures, except vertical jump, were in the first-year similar to male DI football players [17]. The first-year is an important area of focus for strength and conditioning coaches.