To the best of the authors’ knowledge, this study is the first to investigate the physical and physiological demands of male and female beach handball players competing at national top level. A few months after completing this study, the same female and male players finished 1st and 5th during the 2016 Beach Handball World Championship, respectively. Although beach handball differs from team handball in some aspects, the present results will be compared with team handball, but considering its distinctive characteristics and other forms of sand arena sports, such as beach soccer or beach volleyball, to account for the effect of the sandy surface. Beach handball is a heterogeneous high-intensity sport with a variety of physiological demands involving short sprints and short efforts of maximal power and strength. Time-motion analysis showed average match time of 17.7 min and 18.7 min for male and female, respectively. This active time is relatively low compared with team handball 73.6 ± 4.5 min (Póvoas et al., 2012), both for male players, 53.85 ± 5.87 min and female players, 50.70 ± 5.83 min (Michalsik and Aagaard, 2015), where the field surface poses less constraints for locomotion. As a result, there will be differences in the total distance travelled by players, as one of the first GPS variables to be reported, between beach handball and other team sports. Our study reported 1234.7 ± 192.0 m for male players and 1118.2 ± 221.8 m for female players. Studies reported higher total distance covered by team handball players in the range of 3900 to 4700 m (Wagner et al. 2014): male 3945 ± 538 m (Michalsik and Aagaard,2015), female 3627 ± 568 m (Michalsik et al., 2015), 4002 ± 551 m (Michalsik et al., 2013), 3399.2 ± 362.3 m (Belka et al. 2014), 4693 ± 333 m (Michalsik and Aagaard, 2015), and unspecified sex 4964 ± 642 m (Póvoas, 2009), 4370 ± 702 m (Póvoas et al., 2012). The sandy surface of beach handball also affects players’ running demands and therefore, the total match distance. Castellano and Casamichana (2010) analyzed beach soccer players, resulting in a total mean distance of 1135 ± 26.8 m, like the data obtained in our study. Such running demands can also be found in average speed: our study reported 4.2 ± 0.6 km/h and 3.9 ± 0.8 for male and female players, respectively; whereas team handball showed fairly higher values, 6.10 ± 1.01 km/h and 5.31 ± 0.33 for male and female players, respectively (Michalsik and Aagaard 2015). We found that both male and female players covered less distance in the second half, but at the expense of higher average speed, with the female players as main factor in this study (p < 0.01). The latter could be explained in the context of neuromuscular factors in the sandy surface. In addition to muscle fatigue for both groups resulting in lower covered distance, the degree of muscular coordination and stability, which is more important than muscle fiber size, can be an advantage for female players in acquiring faster speeds in second halves. In a sport with an unlimited number of substitutions, such as beach handball, the distance travelled per minute of competition game may be regarded as a scale of match intensity rather than the total distance (Cummins et al., 2013), since total distance may be influenced by the time each player is actively playing. Our results showed that male and female players covered a relative distance similar to team handball: 69.7 m/min and 59.8 m/min, in comparison to 68 ± 9, 60 ± 10, 68 ± 11, 78.9 m/min (Michalsik et al., 2015; 2013; Póvoas, 2009; Póvoas et al., 2012). In spite of similar relative distances, match intensity may be greater due to the sandy surface (Smith, 2006), as reported by Castellano and Casamichana (2010) in beach soccer with 97.7 ± 15.1 m/min. Other studies in indoor small-sided team handball reported higher relative distances, in spite of a reduced court: 110.7, 118.5, 113.3 ± 9.7 m/min (Belka et al. 2014; Corvino et al., 2014; 2016). Contrastingly, Corvino et al. (2014; 2016) reported very high values for 8-min matches in team handball with small-sided courts: 110.7 and 118.5 m/min. Although such courts have almost identical dimensions as in beach volleyball, the reduced play time and the sandy surface, which prevents players from applying fast propulsion in their displacements (Barrett et al., 1997), would explain the huge differences in distance travelled per minute. In this study, work rate patterns were categorized into six speed zones considering beach handball’s specific movements, as an adaptation of similar team sports (Cummins et al., 2013). Similarly to these studies, each zone was linked with a description of the work intensity. Due to the nature of the game, we included the standing speed zone (0–0.4 km/h) as a measure of distance covered in minimal activity and sprinting (>18 km/h) bearing in mind maximal speeds attained during matches. Male players covered most distance while jogging: 432.7 ± 103.3 m and partially cruising: 356.0 ± 100.8 m (zones 4.1–13 km/h) during a match. These findings are in agreement with other studies on small-sided team handball, where the most distance covered was in zone 5–12 km/h: 526.7 ± 30.8 m (Corvino et al., 2014), and 613.4 ± 66.6 m (Corvino et al., 2016). Female players showed lower speed zones of maximal displacement: walking: 407.3 ± 64.3 m and partially jogging: 370.6 ± 94.1 m (zones 0.5–7 km/h) during a match. Again, studies on female team handball reported similar trends: zones 0.5–4 km/h and 0–5 km/h were the zones with most distance travelled (1424 ± 265 m and 2103 ± 334 m, respectively) (Michalsik et al. 2013; Michalsik et al. 2015).We found that male players covered more distance while HI running than female players (p < 0.05), which can be explained by a lower maximum speed in the female team (18.5 km/h). However, since energy expenditure on sand is greater than firm surfaces (Smith, 2006), the physiological and physical profile for activities played on sand must be interpreted with caution (Castellano and Casamichana, 2010). Another measure of high-intensity exertions in team sports is acceleration. Studies on acceleration profiles are limited, with the exception of rugby, using micro sensors (Jones et al., 2015) and GPS motion-analysis (Suárez-Arrones et al., 2012). To calculate the magnitude of effort, changes in velocity are categorized into low-, medium- and high-intensity efforts with different thresholds. Our results reported lower acceleration occurrences than team handball: Barbero et al. (2014) reported total mean values of 113 accelerations and decelerations for the first two 10-min periods in a simulated 30-min match between elite team handball male players (5.6 acc/min), whereas our results showed 53.4 accelerations (2.6 acc/min). Likewise, Luteberget and Spencer (2016) obtained higher acceleration values (over 2.5 m/s2) in official international matches for female team handball (0.7 acc/min) than our results for the combined zones 2 and 3 (0.2 acc/min) in female team suggest. Therefore, the number of accelerations during the game is lower than in team handball since the sandy surface in which exertions are performed would place higher physiological demands on players. Our results indicated that the most common body acceleration was in the low-intensity zone (1–2 m/s2), with 80.9 % and 90.1% of the total for male and female players, respectively. These findings are in agreement with team handball players, spending 84.8% of the total accelerations between 1–2 m/s2 (Barbero et al., 2014). These results suggest that beach handball players spend most of their time in low-intensity activity, as in team handball, but the frequency of occurrence is lower in beach handball (Póvoas et al., 2012). On the other hand, male players performed more moderate- and high-intensity accelerations (zones 2 and 3) than female players (p < 0.05), which can be explained by the high energetic expenditure to perform quick changes in speed on the sand. On average, every 23 s and 27 s, a body acceleration was produced by male and female players, respectively. In addition, 3.9 and 4.7 impacts/min during the game were observed for male and female players, respectively, indicating that impact intensity is lower than team handball, 13.6 impacts/min, (Barbero et al., 2014) and other team sports, such as basketball, 8.2 impacts/min (Puente et al., 2017) or rugby, 21 impacts/min (Cummins et al., 2013). This decrease could be related to the physiological demands of high-intensity activities played on sand, which, despite of their short duration, require high levels of strength and speed. Sand surface acts as a shock absorber, dissipating most of the applied energy, which reduces reaction forces needed to apply fast impulses (Bishop, 2003). Comparing intensities over play time, a number of studies indicated that acceleration values decreased between halves on a range of team sports: soccer (Akenhead et al., 2013), rugby (Higham et al., 2012), Australian football (Varley et al., 2014) and team handball (Wik, 2015). In our study, the number of accelerations in second half periods is 8.8% lower than in first half periods for male players, in accordance with the decrease between 10-min periods of 9.2% (1st to 2nd) and 5.9% (2nd to 3rd) (Barbero et al., 2014). Surprisingly, the female team showed opposite behavior: the number of accelerations increased 21.5% between periods globally (20.2 to 24.5 times) and also in the three intensity categories: 18.8 to 21.5, 1.4 to 2.9 and none to 0.1 (low-, moderate- and high-intensity). According to this study, the intermittent nature of the game may allow sufficient recovery between high-intensity actions to preserve the performance level throughout the match. However, the decrease occurrence of high-intensity activities observed during the second half in team handball cannot be associated to fatigue effect or from changes in game dynamics (Karcher and Buchheit, 2014), so the difference in beach handball players’ sex is actually unclear. HR is a common method to estimate exercise intensity, despite the known variation due to a number of factors (Achten and Jeukendrup, 2003). Our results indicate that beach handball players perform high physiological demands, as depicted by HR. The results of maximal HR (173 ± 13 bpm for male players and 177 ± 13 bpm for female players) are similar to other beach handball studies: 165 ± 13 bpm for recreational male players (Bělka et al., 2015) and female players 174 bpm (Lara-Cobos,2011). Other beach sports showed similar figures, such as beach soccer 188 ± 6 bpm (Castellano and Casamichana, 2010) and 188 ± 11 bpm (Scarfone et al., 2015), and beach volleyball 180 bpm for blocker and 188 bpm for defender (Jimenez-Olmedo et al., 2017). For team handball, maximum values are also comparable: 185 ± 10 bpm (Póvoas et al., 2012) and 182 ± 9 bpm (Cunniffe et al., 2015), being the last two studies performed with female players. The percentage of time spent in each HR zone revealed that zone 3 (71–80% HRmax) and zone 4 (81–90% HRmax) were the most common intensity zones for male and female players, with 26.0% and 29.2% of the total time, respectively. However, in the only study describing such percentages for beach handball, made with male recreational players, the most common intensity zone was higher: >90% HRmax with 39% of total time (Bělka et al., 2015), where HRmax was calculated with a modified version of Tanaka’s formula. In the latter study, a beach volley tournament was played for three hours, followed by a rest period of 60 minutes, before starting three beach handball matches, so the previous load was significant. In our study, percentage values were lower than those reported for other beach sports, such as beach soccer: 59.3 % for >90% HRmax (Castellano and Casamichana, 2010), and 35.0 % for 85–95% HRmax (Scarfone et al., 2015), for small-sided team handball (size 24x12 m): 53.7 % and 56.1% for >90% HRmax (Corvino et al., 2014; 2016), and for team handball: 83% for >85% HRmax (Belka et al. 2014). In these studies, HRmax was calculated with the Yo-Yo Intermittent Recovery Test Level 1, except for small-sided team handball, which used the Karvonen formula. Regarding the comparison between first and second halves, HR mean was higher in the second half, both for male (4.2%) and female players (18.7%). This trend can also be found in female beach handball: 172.16 ± 9.97 b/min vs 176 ± 9 bpm (Lara-Cobos, 2011), and in team handball: 153 ± 19 b/min vs 160 ± 17 bpm (Póvoas et al., 2012). With the exception of zone 6 for male players, low-intensity activities (zones 1 and 2) showed decreased HR over halves, whereas in moderate- and high-intensity activities (zones 3 to 6), an increase in HR was found, both for male and female players. These results are in agreement with the study of Lara Cobos (2011) with female players. The rise in the high-intensity zones could be due to the physiological demands derived from an increased distance covered while HI running and sprinting (males), and cruising and HI running (females), which demands high energy due to the sandy surface, whereas the decrease could be related to the reduction of intensity of the match actions due to fatigue. There are no studies in sand sports relating first and second halves by HR zones, but in team handball, mixed results can be found, showing either a similar trend, where low-intensity zones decreased and high-intensity increased (Lara-Cobos, 2011), or the opposite behavior (Belka et al., 2014; Cunniffe et al., 2015). However, since beach handball is typically performed outdoors under hot environmental conditions, high sweat losses would produce dehydration trough match time. Therefore, the increase in HR through halves may also be explained by the effect of cardiovascular strain on players, since every 1% of body weight loss due to dehydration increases HR by 5–8 b/min (Magalhães et al., 2011). The main findings of our study were that beach handball players covered substantially more distance in the first half but at the expense of lower speed, mostly due to female players. In addition, the same group showed lower percentage of time in low HR zones (<60% and 61–70% HRmax) in the first half and opposite trend for high HR zones: the percentage of time in high HR zones (81–90%, 91–95% and >95% HRmax) was higher for the second half. As a consequence, the mean HR value was substantially higher in the second half (18.7%). The effect size of these results was mostly large. |