Team handball is a professional and Olympic sport that has become increasingly popular over the past decades; the International Handball Federation (IHF) reports ∼19 million players in ∼795,000 teams (18). Handball is a team sport characterized by intense, intermittent activities including running, sprinting, and jumping, as well as regular throwing, hitting, blocking, and pushing between players (13,15). Therefore, success in team handball is determined by a variety of technical-tactical, psychological, anthropometric, and physical performance characteristics (35). Identifying the most important qualities for successful team handball performance is of great interest for establishing which variables are of most importance in developing optimal strength and conditioning programs.
In addition to technical-tactical skills and anthropometric characteristics, it may be hypothesized that high levels of running speed, jumping, muscle strength, and throwing velocity will be important for successful participation at the elite handball level (14). In addition, the final outcome of the match is dependent on the team scoring the most goals, requiring players to execute throws that often require high velocity to outpace the goalkeeper (21). Therefore, the handball throw is a fundamental skill that players must develop to increase their proficiency in the sport. The basic factors influencing the efficiency of the handball throw are accuracy and throwing velocity (32–34). Female elite players have demonstrated 11–27% higher throwing velocities than female nonelite players (16,27). It has been suggested that slow throwing might be explained by poor technique and low strength and/or power of the upper and lower limbs, resulting in reduced efficiency during the transfer of momentum through the pelvis and trunk to the throwing arm (27,36).
Despite the relevance of throwing velocity for success in team handball and the significance of strength levels in performance, little information is available concerning throwing velocity and strength levels in both the upper and lower-limb muscles in handball players of different levels. Two studies reported significant relationships between throwing velocity and upper extremity isokinetic torque (2,10). However, the isokinetic test does not reflect the natural movements of the limbs involved during most sport activities, including handball throwing. Using barbells and lifting the load at maximal velocity reflects athletes' functional strength more accurately. Studies using this test have reported significant relationships between throwing velocity and barbell velocity at 30% of 1-repetition maximum in bench press exercises (r = 0.67–0.71) (10), and between throwing velocity and light absolute loads in bench press (26 and 36 kg; r = 0.56–0.63) (21). In addition, previous studies have found significant relationships between peak power in squat and throwing velocity (r = 0.57–0.62) (5,14). Taken together, these data suggest that throwing velocity is related to the capacity to move low loads with the upper limbs at maximal velocities, and the peak power generated by the lower limbs. However, to our knowledge, no study has analyzed the relationships between upper- and lower-limb strength, sprint capacity and jump ability with throwing velocity.
Determining the physical profiles of young handball players will allow the identification of strengths and weaknesses in areas relevant to performance and allow the design of specific, focused training models to improve performance (27). Therefore, the aims of this investigation were to: (a) analyze the evolution of throwing velocity and different fitness parameters (upper and lower-limb strength, running sprint and jump abilities) at different ages in male handball players and (b) examine the relationships between throwing velocity and the different fitness parameters analyzed. Our hypothesis is that there are differences in physical performance between the different age groups of handball players and that there are relationships between throwing velocity and upper- and lower-limb strength.
Material and Methods
Experimental Approach to the Problem
A cross-sectional experimental design was used to determine the differences between male handball players of different ages (professional “ELITE” vs. under-18 “U18” vs. under-16 “U16”) in specific handball throwing and fitness parameters, such as sprint, jump ability, and muscle strength, and to analyze the relationships between these fitness parameters and handball throwing velocity. All the tests were completed at the end of the preseason (September) and were performed in 2 testing sessions separated by at least 2 days. As the time of day can influence both aerobic and anaerobic performance (7), all tests were conducted at the same time of day, from 17:00 to 21:00 hours. After preliminary familiarization and pretesting, subjects completed all tests. In the first testing session, a battery of tests were performed in the following order: (a) 20-m running sprints; (b) countermovement vertical jumps; (c) countermovement jump (CMJ) with external load on a Smith machine; and (d) a progressive loading test in full squat (SQ). In the second testing session, players completed: (a) specific handball throwing tests and (b) a progressive loading test in bench press (BP). In the 2 weeks preceding testing, 4 preliminary familiarization sessions were undertaken with the purpose of emphasizing proper execution technique for the tests assessed. Anthropometric assessment was performed during the familiarization sessions. Sessions were performed under the direct supervision of the investigators, at the same time of day for each subject and under constant environmental conditions (20° C, 60% humidity). Before the tests were completed, subjects executed a standardized warm-up directed by the primary researcher along with the coach. During the execution of these tests, the players were verbally encouraged to give their maximal effort. The tests executed for the measurement of performance are explained in detail below.
A total of 44 handball players (age range, 14–33 years) participated in this investigation. The handball players were members of the elite team or the development program of the same professional handball club in the ASOBAL handball league in Spain. According to the Handball Federation rules, players are matched and compete by chronological age rather than biological maturation. Thus, in this study, players were pooled by age group (ELITE, n = 13; U18, n = 16; and U16, n = 15). The mean ± SD age, height, and body mass of the 3 groups are presented in Table 1. All the players participated on average in ∼16 hours of combined handball-specific training and competitive play per week (4–5 handball training sessions, 1–2 strength training sessions, 1–2 conditioning sessions, and 1 official game per week). Written, voluntary consent was obtained from the participants (and the participants' parents or guardians if the player was younger than 18 years), after being thoroughly informed of the purpose, testing procedures, and potential risks of the study. The present investigation was approved by the Research Ethics Committee of Pablo de Olavide University.
The subjects ran two 20-m races on an indoor track, separated by 3 minutes of rest. The starting position was standardized, with the lead-off foot behind the starting line, which was placed 1 m behind the first time gate. The photocell gates were placed at the start, and at 10 and 20 m. The subjects attempted to run the 20 m in the least possible time. The best time from the 2 attempts in the following splits was recorded: 0–10 m (T10), 10–20 m (T10–20), and 0–20 m (T20). A standardized warm-up protocol was performed, which incorporated several sets of progressively faster 30 m running accelerations. Sprint times were measured using photocells (Polifemo Radio Light; Microgate, Bolzano, Italy).
Jump height was calculated to the nearest 0.1 cm from flight time measured with an infrared timing system (Optojump; Microgate). The displacement of the center of gravity during the flight was estimated from the jumping height (h), which was calculated using the recorded flight time as follows (3): h = (g·ft2)·8−1, where “g” is the acceleration due to gravity (9.81 m·s−2) and “ft” is flight time. Since the take-off and landing position can affect the jump flight, strict instructions were given to all participants to keep their legs straight during the flight time of the jump. The player starts from an upright standing position, makes a downward movement to a knee angle of approximately 90°, and subsequently begins to push off at maximal intended velocity. All participants completed 5 maximal CMJs with their hands on their hips separated by 1 minute rest. The highest and lowest values were discarded, and the resulting average value was kept for analysis.
Jump height was calculated to the nearest 0.1 cm from flight time measured with an infrared timing system (Optojump; Microgate). The jump height was calculated using a similar procedure to jumps without external load. Two minutes of recovery was given between jumps, and each of the loads was set using the Smith machine. The test began with a load of 20 kg, and the weight was increased in 10 kg increments. The test ended when the subject jumped to a height of less than 20 cm. The load with which subjects were able to jump 20 cm was set as the reference (JSLOAD-20 cm). This load has been previously used as a reference to schedule training programs in this exercise (20).
Isoinertial Strength Assessment
Strength performance was assessed using a progressive loading test for the individual load-velocity relationship in the SQ and BP exercises on a Smith machine (Multipower Fitness Line; Peroga, Murcia, Spain). The BP was performed using a momentary pause (∼1.5 seconds) at the chest between the eccentric and concentric actions to minimize the contribution of the rebound effect and allow for more reproducible, consistent measurements (28). The SQ was performed with subjects starting from the upright position with the knees and hips fully extended. Each subject descended in a continuous motion until the tops of the thighs were below the horizontal (ground) plane, then immediately reversed motion and ascended back to the upright position. Unlike the eccentric phase, which was performed at a controlled mean velocity (∼0.50–0.65 m·s−1), subjects were required to always execute the concentric phase of either BP or SQ in an explosive manner, at maximal intended velocity. The initial load was set at 20 kg and was progressively increased in 10 kg increments. Subjects performed 3 repetitions with each load. Only the best repetition at each load, according to the criterion of fastest mean propulsive velocity (30) was considered for subsequent analysis. Four minutes of recovery was assigned between sets. The test ended when the average velocity of lifting was less than 1 m·s−1 in SQ and less than 0.8 m·s−1 in BP. The absolute load at which players were able to elicit a velocity of ∼1.00 m·s−1 was used to assess strength performance in SQ (SQ-V1-LOAD) and BP (BP-V1-LOAD). In addition, relative strength was assessed through the load at which handball players were able to elicit a velocity of ∼1.00 m·s−1 in full squat and bench press exercises divided by their body weight (SQ-V1-LOAD·BM−1 and BP-V1-LOAD·BM−1, respectively). This load was chosen for several reasons: (a) This load has been used previously to assess strength performance in highly trained athletes (12); and (b) larger weights may predispose athletes to a higher risk of ventral flexion of the lumbar spine while squatting (19). Warm-up consisted of 5 minutes of joint mobilization exercises, followed by 2 sets of 6 repetitions (3 minutes rests) with 20 kg. A dynamic measurement system (T-Force System; Ergotech, Murcia, Spain) automatically calculated the relevant kinematic parameters of every repetition, provided auditory and visual velocity feedback in real-time and stored the data on disk for analysis. This system consists of a linear velocity transducer interfaced to a personal computer by means of a 14-bit resolution analog-to-digital data acquisition board and custom software. Instantaneous velocity was sampled at 1,000 Hz and subsequently smoothed using a fourth order low-pass Butterworth filter with no phase shift and a cutoff frequency of 10 Hz. The reliability of this system has been recently reported elsewhere (29). The velocity measures used in this study correspond to the mean velocity of the propulsive phase of each repetition (30). The propulsive phase was defined as that portion of the concentric phase during which barbell acceleration was greater than the acceleration due to gravity.
Handball Throwing Test
Specific explosive strength production in handball was evaluated on an indoor handball court using an overarm throw, in 2 situations: 3-step throw and jump throw. After a 10-minute standardized warm-up, directed by the researcher, which consisted of specific passing and throwing, in which velocity was progressively increased, the players were instructed to throw a standard handball size III (mass: 480 g, circumference: 58 cm) at maximal intended velocity at a circled target of 1-meter diameter located in the middle of a goal (3 × 2 m), using one hand and their own throwing technique, but following the instructions for either the jump throw or the 3-step throw as follows. In the jump throw, the players dribbled the ball from midfield (20 m from the goal), and were limited to a 3-step approach to perform the jump throw without stepping over a line 9 m from the goal. In the 3-step throw, the subjects had to repeat the same sequence as in the previous release but when they reached the throwing area they had to complete the throw with one foot in contact with the floor behind the line 9 m from the goal. All players completed 5 maximal throws of each type, with an interval of 2 minutes between them. The highest and lowest values were discarded, and the resulting average value was kept for analysis. The speed of each throw was measured using a radar device (Stalker Sport; Applied Concepts, Inc., Plano, TX, USA). The radar unit was placed a short distance from the ball (2 m) behind the indoor handball goal, and elevated 1 m above the ground. Coaches ensured that the throwing test complied with the rules established, and the attempt was disallowed if the cited rules were not followed. For motivation, subjects were immediately informed of their performance.
Values are reported as mean ± standard deviation (SD). Statistical significance was established at the p ≤ 0.05 level. The distribution of each variable was examined using the Shapiro-Wilk normality test. Homogeneity of variance was verified using Levene's test. An intraclass correlation coefficient (ICC) with a 95% confidence interval (CI) was used to determine the between-subject reliability of tests. Within-subject variation for the tests was determined by calculating the coefficient of variation (CV). The statistical differences between groups (ELITE vs. U18 vs. U16) were tested using an analysis of variance with Bonferroni's post hoc comparisons. In addition to this null hypothesis testing, data were assessed for clinical significance using an approach based on the magnitudes of change (1). The standardized differences or Cohen's d (90% CI) were calculated using the pooled SDs (8), to estimate the magnitude of the differences between groups. For between-group comparisons, the chance that the true (unknown) values for each category condition were beneficial/better (i.e., greater than the smallest practically important or worthwhile effect [0.2 × between-subject SD, based on Cohen's effect size principle (3)]), unclear or detrimental/worse for performance were calculated. Quantitative chances of beneficial/better or detrimental/worse effects were assessed qualitatively as follows: <1%, almost certainly not; 1–5%, very unlikely; 5–25%, unlikely; 25–75%, possible; 75–95%, likely; 95–99%, very likely; and >99%, almost certain. If the chances of having beneficial/better or detrimental/worse were both >10%, the true difference was assessed as unclear (1). In addition, linear regressions with Pearson's coefficients (r) and 90% CI were used to calculate the respective relationships between the performance parameters analyzed. Inferential statistics based on interpretation of magnitudes of effects were calculated using a purpose-built spreadsheet to compare 2 groups (1). The rest of the statistical analyses were performed using SPSS software version 18.0 (SPSS, Inc., Chicago, IL, USA).
Mean values and SDs of the variables assessed are reported in Table 2. Test-retest reliabilities for T10, T20, and T10–20 as measured by the CV were 1.7, 1.0, and 2.3%, respectively, and the ICCs (95% CI) were 0.92 (0.87–0.96), 0.96 (0.94–0.98), and 0.93 (0.87–0.96). For CMJ height, CV was 1.8%, and ICC (95% CI) was 0.99 (0.98–0.99). For both types of throwing, CV was 1.5% and ICC (95% CI) was 0.99 (0.98–0.99).
ELITE showed significantly better performance than U18 (p = 0.01; 99/1/0%) and U16 (p = 0.05; 98/2/0%) for T10. Furthermore, ELITE showed significantly better performance in T20 compared with U18 (p = 0.05; 97/2/0%) and the results were almost significant with regard to U16 (p = 0.08; 99/1/0%). Although no significant differences (p > 0.05) were found for T10–20 between any groups, ELITE showed a likely better T10–20 performance than U18 (80/17/3%) and U16 (92/7/1%). The differences between U18 and U16 for all running sprints times were unclear (Figure 1).
ELITE showed significantly (p < 0.01) better performance than U18 and U16 for CMJ height, whereas no significant differences (p > 0.05) were found for CMJ height between U18 and U16. Furthermore, ELITE showed a most likely better CMJ height performance than U18 and U16, and the chances that the true changes were greater/similar/lower for ELITE than U18 and U16 were 100/0/0% (Figure 1). The beneficial effects of U18 compared with U16 on CMJ were unclear (34/46/20%). With respect to JSLOAD-20 cm, ELITE showed an almost certain better level of performance than U18 and U16 (p < 0.001, 100/0/0%). The differences between U18 and U16 for JSLOAD-20 cm were unclear (p > 0.05; 46/38/16%).
Isoinertial Strength Assessments
With regard to absolute and relative squat strength assessed using SQ-V1-LOAD and SQ-V1-LOAD·BM−,1 respectively, ELITE showed better performance than the U16 and U18 groups (p < 0.001; 100/0/0%). The U18 group showed better performance for SQ-V1-LOAD (p = 0.001; 100/0/0%) and SQ-V1-LOAD·BM−1 (p = 0.07; 96/4/0%) than U16. For BP-V1-LOAD and BP-V1-LOAD·BM−1, ELITE showed significantly (p = 0.000–0.001) better performance than U18 and U16, whereas the differences between U18 and U16 were unclear (Figure 1).
ELITE showed significantly better performance for both the jump throw and the 3-step throw than U18 and U16 (p < 0.001; 100/0/0%). U18 attained significantly greater performance than U16 for the jump throw (p < 0.01; 100/0/0%) and the 3-step throw (p ≤ 0.05; 99/1/0%).
Relationships Between Fitness Parameters and Throwing Velocity
Running sprint times showed significant relationships (p = 0.001–0.05) with jump throw (T10: r = −0.51; T20: r = −0.50; and T10–20: r = −0.41) and 3-step throw (T10: r = −0.35 and T20: r = −0.31), except for T10–20 with 3-step throwing (r = −0.21, p > 0.05). Jump ability also correlated significantly (p < 0.001–0.01) with the jump throw (CMJ: r = 0.56 and JSLOAD-20 cm: r = 0.60) and the 3-step throw (CMJ: r = 0.39 and JSLOAD-20 cm: r = 0.57). Muscle strength was also significantly associated (p < 0.001) with the jump throw (SQ-V1-LOAD: r = 0.76; SQ-V1-LOAD·BM−1: r = 0.67; BP-V1-LOAD: r = 0.70; and BP-V1-LOAD·BM−1: r = 0.57) and 3-step throw (SQ-V1-LOAD: r = 0.73; SQ-V1-LOAD·BM−1: r = 0.66; BP-V1-LOAD: r = 0.48; and BP-V1-LOAD·BM−1: r = 0.33) (Table 3).
A limited number of studies have assessed some of the anthropometric, physical fitness, and handball-specific characteristics of youth and adult handball players (5,6,9,14,21,22,25–27). However, to our knowledge, no study has analyzed the velocity-power-strength characteristics of the upper and lower limbs in handball players of different ages along with the relationships between these fitness parameters and handball throwing velocity. Therefore, the purposes of this study were: (a) to analyze the evolution of throwing velocity and different fitness parameters (upper- and lower-limb strength, running sprint, and jump abilities) in male handball players of different ages and (b) to examine the relationships between throwing velocity and the different fitness parameters analyzed. One of the main findings of this study was that greater velocities for jump throw and 3-step throw correlated with increased handball performance. Moreover, lower-limb strength seemed to be the main fitness parameter determining throwing performance, although upper-limb strength, jumping ability, and running sprint capacity also play a role in the ability to throw a ball at high velocity.
Handball players who displayed greater throwing velocity (both jump throw and 3-step throw) showed better handball performance (Table 2). The 3-step throw velocity observed for ELITE handball players in this study was 25.7 ± 1.9 m·s−1. These results are in line with those observed by other researchers in handball players with similar characteristics: 26.0 ± 2.4 m·s−1 (5), 24.0 ± 1.7 m·s−1 (21), and 25.3 ± 2.2 m·s−1 (14); and higher than those reported for intermediate-level handball players (second and/or third European divisions): 22.9 ± 1.4 m·s−1 (14), 23.4 ± 2.5 m·s−1 (11), and 23.2 ± 1.6 m·s−1 (34). The values for 3-step throw velocity reported for U18 (22.0 ± 1.5 m·s−1) and U16 (20.2 ± 1.7 m·s−1) groups were higher than those reported for novice handball players: 18.0 ± 0.2 m·s−1 (31). From these data, we can speculate that a higher ball throwing velocity is a key factor for attaining higher handball performance levels. With regard to jump throw, to our knowledge, only 1 previous study has analyzed this kind of jump (17). Hermassi et al. (17), measured higher velocity values in this type of jump than those observed in this study (30.1 ± 3.5 vs. 24.7 ± 2.0 m·s−1, respectively). However, these authors recorded the throwing velocities using digital video camera analysis (17). Therefore, comparison between the studies must remain tentative because of the differences in methodological factors.
The ability to sprint over short distances is of great importance for top-level playing performance, for players to reposition themselves during transitions between attack and defense phases, and during fast breaks and offensive breakthroughs (23). This study observed that ELITE players achieved superior sprint performance (T10, T20, and T10–20) compared with U18 and U16 players, whereas the differences between U18 and U16 for all running sprint times were unclear (Figure 1). A previous study showed that elite players have superior 20-m sprint speeds compared with those of players of lower standard, whereas no differences were observed between elite and nonelite players (27). In addition, Gorostiaga et al. (14) did not observe differences in sprint performance between elite and amateur handball players. By contrast, other previous studies have observed differences in sprint running performance between playing levels in handball players (22,37). With regard to jump ability, ELITE players displayed greater CMJ and JSLOAD-20 cm performance than U18 and U16, whereas no differences were found for jump performance between U18 and U16 (Figure 1). To our knowledge, this is the first study to analyze jump squat performance at different playing levels in handball players. Our CMJ data are in line with those observed in a previous study that found CMJ heights for top-elite players were ∼4–5 cm higher than elite and nonelite handball players (27). In addition, an earlier study also found better jump performance in elite youth players compared with nonelite youth players only in the older group (U16–U18), whereas no significant differences between the levels were revealed in the younger group (U14–U16) (22). These authors suggest that the importance of strength increases with age when playing at an elite level (22). Improved performance for top-elite players is a key factor, given the relevance of jumping in handball activities such as throwing and blocking (4,24).
With regard to muscle strength, ELITE showed better performance than the U16 and U18 groups both in upper and lower limbs (Figure 1). In addition, the U18 group showed greater lower-limb strength than U16, without differences in upper-limb strength. These strength differences between levels of handball performance have also been observed in a previous study (14). These authors reported that elite handball players showed greater absolute strength in the muscles of the upper and lower extremities during BP and half-squat absolute and relative strength are required for successful performance in elite handball, to execute the strength-demanding physical actions required during some handball game situations, including accelerations and decelerations, hitting, blocking, holding, and pushing.
Concerning the relationships between muscle strength and handball throwing velocity, the results indicate that those players with higher strength values in BP actions may be able to throw the ball (both with and without jump) at higher velocities than those with lower values (BP-V1-LOAD: r = 0.70; 0.48 and BP-V1-LOAD·BM−1: r = 0.57; 0.33 for jump throw and 3-step throw, respectively). Therefore, the ability to apply force with the upper limbs during press movements seems to be linked to the ability to throw the ball quickly. This assumption is supported by previous studies that showed significant relationships between bench press strength and throwing velocity (r = 0.55–0.72) (9,14,21). However, in this study, this indicator accounted for just 10–50% of the total variance. However, squat strength accounted for 44–58% of total variance (jump throw [SQ-V1-LOAD: r = 0.76; 0.73; SQ-V1-LOAD·BM−1: r = 0.67; 0.66] for jump throw and 3-step throw, respectively). Taken together, these data suggest that throwing velocity might be more related to the capacity to apply force with the lower limbs than with the upper-limb muscles. The relationships between throwing velocity and sprinting and jumping capacities have not been sufficiently investigated. In this study, jump ability correlated significantly (p < 0.001–0.01) with the velocity attained in both types of throwing. The relationships were higher for the jump throw (CMJ: r = 0.56; and JSLOAD-20 cm: r = 0.60) than for the 3-step throw (CMJ: r = 0.39; and JSLOAD-20 cm: r = 0.57). In addition, this study also found relationships between running sprint times and throwing velocity. Similar to jump ability, relationships were higher for the jump throw (T10: r = −0.51; T20: r = −0.50; and T10–20: r = −0.41) than for the 3-step throw (T10: r = −0.35; T20: r = −0.31; and T10–20: r = −0.21), indicating that improvements in jump height and running sprints might benefit throwing performance, particularly in throwing preceded by a jump.
Handball players showed greater throwing velocities, jump height, running sprint capacity, and muscle strength in upper and lower extremities as their handball performance increased. In addition, handball throwing velocity seems to be strongly associated with the strength of the muscles in the lower extremities, although muscle strength in the upper extremities, jumping ability, and running sprint capacity also play a role in throwing performance. Therefore, our results highlight the contribution of both upper and lower-limb strength to handball throwing velocity, suggesting the need for coaches to include upper- and lower-limb strength programs to improve handball players' throwing velocity. Consequently, both general strength training and specific physical training should be used to target these performance components to optimize the functional capacity in handball players. Moreover, the current study may indicate that factors of physical performance such as muscle strength, running sprints, jumps, and specific throwing in handball players are important parameters for talent identification. Future investigations should include appropriate strength programs (exercise, load, and velocity-based prescription) with handball players of different ages.
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