Neuromuscular and technical abilities related to age in water-polo players

A Research Note on Relationships Between Age, Body Size, Strength, and Power With Throwing Velocity in High School Water Polo Players

ABSTRACT

Lockie, RG, Wakely, AM, Viramontes, E, and Dawes, JJ. A research note on relationships between age, body size, strength, and power with throwing velocity in high school water polo players. J Strength Cond Res 37(8): e466-e469, 2023-A successful high school strength and conditioning program should aim to improve fitness and develop motor skills in athletes. This research note investigated the relationships between throwing velocity with age, height, body mass, strength, and power in male high school water polo athletes. Fifteen (n = 15) water polo athletes (age: 15.67 ± 0.98; height: 177.63 ± 6.53 cm; body mass: 78.07 ± 16.08 kg) from one high school program were recruited. Strength was measured using combined grip strength from both hands and a leg/back dynamometer. Power was measured by a vertical jump and 2-kg seated medicine ball throw (MBT). Subjects also threw a water polo ball with maximum effort to measure throwing velocity. Pearson's correlation and stepwise regression were used to calculate relationships between throwing velocity with age, body size, strength, and power (p < 0.05). Age (r = 0.530), grip strength (r = 0.674), leg/back strength (r = 0.699), and the MBT (r = 0.670) all showed significant positive relationships with throwing velocity. Leg/back strength predicted throwing velocity with 49% explained variance (r2 = 0.490, p < 0.004). With age, explained variance increased to 66% (r2 = 0.664, p < 0.001). Throwing velocity related to age, which could be expected with maturation. However, stronger relationships were seen for upper-body (grip) and lower-body (leg/back) strength, and upper-body power (MBT). Strength and conditioning programs for high school athletes who develop upper- and lower-body strength and upper-body power could enhance throwing velocity among water polo (and potentially other overhead throwing) athletes.

Effects of Plyometric Jump Training on Measures of Physical Fitness and Sport-Specific Performance of Water Sports Athletes: A Systematic Review with Meta-analysis

Background

A growing body of literature is available regarding the effects of plyometric jump training (PJT) on measures of physical fitness (PF) and sport-specific performance (SSP) in-water sports athletes (WSA, i.e. those competing in sports that are practiced on [e.g. rowing] or in [e.g. swimming; water polo] water). Indeed, incoherent findings have been observed across individual studies making it difficult to provide the scientific community and coaches with consistent evidence. As such, a comprehensive systematic literature search should be conducted to clarify the existent evidence, identify the major gaps in the literature, and offer recommendations for future studies.

Aim

To examine the effects of PJT compared with active/specific-active controls on the PF (one-repetition maximum back squat strength, squat jump height, countermovement jump height, horizontal jump distance, body mass, fat mass, thigh girth) and SSP (in-water vertical jump, in-water agility, time trial) outcomes in WSA, through a systematic review with meta-analysis of randomized and non-randomized controlled studies.

Methods

The electronic databases PubMed, Scopus, and Web of Science were searched up to January 2022. According to the PICOS approach, the eligibility criteria were: (population) healthy WSA; (intervention) PJT interventions involving unilateral and/or bilateral jumps, and a minimal duration of ≥ 3 weeks; (comparator) active (i.e. standard sports training) or specific-active (i.e. alternative training intervention) control group(s); (outcome) at least one measure of PF (e.g. jump height) and/or SSP (e.g. time trial) before and after training; and (study design) multi-groups randomized and non-randomized controlled trials. The Physiotherapy Evidence Database (PEDro) scale was used to assess the methodological quality of the included studies. The DerSimonian and Laird random-effects model was used to compute the meta-analyses, reporting effect sizes (ES, i.e. Hedges’ g) with 95% confidence intervals (95% CIs). Statistical significance was set at p ≤ 0.05. Certainty or confidence in the body of evidence for each outcome was assessed using Grading of Recommendations Assessment, Development, and Evaluation (GRADE), considering its five dimensions: risk of bias in studies, indirectness, inconsistency, imprecision, and risk of publication bias.

Results

A total of 11,028 studies were identified with 26 considered eligible for inclusion. The median PEDro score across the included studies was 5.5 (moderate-to-high methodological quality). The included studies involved a total of 618 WSA of both sexes (330 participants in the intervention groups [31 groups] and 288 participants in the control groups [26 groups]), aged between 10 and 26 years, and from different sports disciplines such as swimming, triathlon, rowing, artistic swimming, and water polo. The duration of the training programmes in the intervention and control groups ranged from 4 to 36 weeks. The results of the meta-analysis indicated no effects of PJT compared to control conditions (including specific-active controls) for in-water vertical jump or agility (ES =  − 0.15 to 0.03; p = 0.477 to 0.899), or for body mass, fat mass, and thigh girth (ES = 0.06 to 0.15; p = 0.452 to 0.841). In terms of measures of PF, moderate-to-large effects were noted in favour of the PJT groups compared to the control groups (including specific-active control groups) for one-repetition maximum back squat strength, horizontal jump distance, squat jump height, and countermovement jump height (ES = 0.67 to 1.47; p = 0.041 to < 0.001), in addition to a small effect noted in favour of the PJT for SSP time-trial speed (ES = 0.42; p = 0.005). Certainty of evidence across the included studies varied from very low-to-moderate.

Conclusions

PJT is more effective to improve measures of PF and SSP in WSA compared to control conditions involving traditional sport-specific training as well as alternative training interventions (e.g. resistance training). It is worth noting that the present findings are derived from 26 studies of moderate-to-high methodological quality, low-to-moderate impact of heterogeneity, and very low-to-moderate certainty of evidence based on GRADE.

Trial registration The protocol for this systematic review with meta-analysis was published in the Open Science platform (OSF) on January 23, 2022, under the registration doi https://doi.org/10.17605/OSF.IO/NWHS3 (internet archive link: https://archive.org/details/osf-registrations-nwhs3-v1).

Youth Water Polo Performance Determinants: The INEX Study

Due to the growing engagement of youth in water polo practice, we aimed to characterize age-grouped players across anthropometric, general and specific motor abilities and contextual domains. We have also examined the associations of players' specific skills with their anthropometric and general motor characteristics. One-hundred-and-one male water polo players, grouped into 12-, 13- and 14-year age cohorts were recruited. One-way ANOVA explained age-cohort variance, and a multiple linear regression was used to assess the association between variables. The variance in cohorts was explained by arm span (25%), stature, hand breadth and length (17%) fat-free mass (18%), 20 m sprint (16%), sit-ups (18%), medicine ball throw (27%), anaerobic (31%) and aerobic performance (21%), change of direction (18%), and in-water vertical jump (14%). The variance of in-water vertical jump, 10 m sprint, change of direction and aerobic fitness for players' anthropometric characteristics were, 32, 25, 14 and 10% (respectively). The players' upper-limb explosive power explained 30, 22 and 17% of variance for in-water vertical jump, 10 m sprint and aerobic fitness, respectively. Body mass had an inverse, and arm span had a direct association with in-water vertical jump and swim velocity capability, arm span had an inverse and direct association with change of direction and aerobic fitness, respectively. The upper limbs' explosive power related directly to in-water vertical jump and aerobic fitness skills, but inversely with 10 m sprint scores.

Goal Shot Analysis in Elite Water Polo—World Cup Final 2018 in Berlin

The subject of this game analysis was the throwing behavior of the world class players under competition match conditions during the final “World Cup Water Polo” tournament 2018 in Berlin. Specifically, we analyzed (a) the situational dependence of concrete environmental conditions (“constraints”) of successful throwing actions as well as (b) the goal throw biomechanics concerning throwing speed. Therefore, player’s and ball positions were recorded by video cameras as well as high-speed cameras. Based on the positions and trajectories parameters such as goal throw speed, Voronoi-cells as well as team centroids were calculated. The area of the Voronoi-cells differs concerning defending and attacking teams as well as between successful and non-successful teams and can be used as an indicator for goal or no goal. Under semi-collective tactical aspects, the comparison of the offensively and defensively controlled field areas (collective space control) between successful and unsuccessful goal throws shows that in the case of successful attacking completions, the attacking team (in the sum of its six players) each controlled significantly more field area in front of the opponent’s goal than the six defensive players together with their goalkeeper. In the case of unsuccessful attacking attempts, this area ratio was exactly reversed, i.e., the defensive team dominated the space.

Physical and performance variables for talent identification in water polo

BACKGROUND

The aim of this work was to compare anthropometric and general physical performance variables in young water polo athletes of three competitive levels, to identify the characteristic qualities and, therefore, the best variables for the identification of talent.

METHODS

Fifty-seven young male water polo players between 12 and 14 years old were recruited for the study: 18 were recreational level (REC), 18 sub-elite level (SE) and 21 elite level (EL). To assess anthropometric characteristics the following measurements were used: body mass, height, waist circumference, hip circumference, chest circumference and arm span. Five general performance measures were used: counter movement jump (CMJ), triple hop jump (THJ), push up, chin up and sit up. Relative age was assessed.

RESULTS

The whole sample was homogeneous by age (REC 13.1±0.4, SE 13.2±1.0, EL 13.3±0.7 years old) but not in terms of relative age: most of the members of the SE and EL groups were born in the first half of the year. Body mass values (REC 48.2±11.6, SE 59.3±11.6, EL 69.1±4.2 kg) show statistically significant differences between all three competitive levels (REC vs. SE P=0.007, REC vs. EL P=0.001, SE vs. EL P=0.009). As regards the other anthropometric measurements differences were mainly observed between REC and the two other groups: SE and EL had statistically significant higher values in almost all of the measurements carried out. Among the performance measures, lower limb strength (CMJ and THJ) seems to better differentiate between groups: REC group had lower values than the others and EL had the highest values.

CONCLUSIONS

Anthropometric characteristics are useful to distinguish the basic level of youth categories from higher competitive levels and should be used for talent selection. The performance results confirm that the subjects' capacity to be trained and sporting practice are essential to reach the elite level.

Validity, Reliability, and Usefulness of My Jump 2 App for Measuring Vertical Jump in Primary School Children

There is a persistent need in sport science for developing a measuring tool that is affordable, portable, and easy to use. We aimed to examine the concurrent validity and test-retest reliability of the My Jump 2 app compared to a validated OptoJump instrument for measuring jump performance during the squat jump (SJ), countermovement jump (CMJ), and CMJ free arms (CMJAM) in primary school children. A total of 48 participants (11-14 years age), volunteered to participate in this research. The jumps were recorded with a validated OptoJump photoelectric cell system and a concurrent device (iPhone X through My Jump 2 app) at the same time. The participants repeated the testing procedure after two weeks to assess the reliability of the measurements (ICC). Systematic bias between sessions and tools was evaluated using the paired samples t-test and Bland and Altman analysis. High test-retest reliability (ICC > 0.89) was observed for all measures' in-between conditions. Very large correlations in the total sample were observed between the My Jump 2 app and OptoJump for SJ (r = 0.97, p = 0.001), CMJ (r = 0.97, p = 0.001), and CMJAM (r = 0.99, p = 0.001). Bland and Altman's plot depicting limits of agreement for the total sample between the OptoJump and My Jump 2 show that the majority of data points are within the 95% CIs. The results of this study suggest that My Jump 2 is a valid, reliable, and useful tool for measuring jump performance in primary school children.

The ball kicking speed: A new, efficient performance indicator in youth soccer

Success in different soccer skills like kicking depends on motor abilities achieved. Kicking is a soccer fundamental, which depends on many different and complex factors (technique, foot-ball interaction, ball flight, etc.). Therefore, it is important to identify players that are able to perform faster kicks using both dominant and non-dominant leg. The current study investigated some basic variables of different soccer kicking speed and their relevance to success in youth soccer academy. 119 players from the first and the second division participated to this study. They were randomly divided into age groups (U-15, U-17, and U19) and team status (first team, reserves). The diagnostic ability of the different ball kicking speed tests in capturing differences between first team players and reserves among different age categories were computed using the receiver operating characteristics analysis. Results demonstrated that first team players achieved better results when comparing to reserves in each category. In addition, differences were greater in the U-15 and the U-17 than in the U-19 age group. In conclusion, ball kicking speed could be one of the possible identification tools to evaluate players' success in youth soccer.

Validity and Reliability of the 30-s Continuous Jump for Anaerobic Power and Capacity Assessment in Combat Sport

Cycling test such Wingate anaerobic test (WAnT) is used to measure anaerobic power (AP), but not anaerobic capacity (AC, i.e., the metabolic energy demand). However, in sports that do not involve cycling movements (Karate), the continuous jump for 30 s (vertical jumps for 30 s) has been extensively used to measure anaerobic performance in all young athletes. Limited information’s are available concerning its validity and reliability especially in children. As such, the current study aimed to test validity and reliability of a continuous jumps test (the CJ30s), using WAnT as a reference. Thirteen female Karate kids (age: 11.07 ± 1.32 years; mass: 41.76 ± 15.32 kg; height: 152 ± 11.52 cm; training experience: 4.38 ± 2.14 years) were tested on three separate sessions. The first and second sessions were used to assess the reliability using Intra-class correlation coefficient (ICC) of CJ30s, whereas on the third session WAnT was administered. Following CJ30s and WAnT, we assessed AP (1/CJ30s, as jump height [JH], fatigue index [FI], and blood lactate [BL]; 2/WAnT, as mechanical power [P], FI, and BL) and AC as the excess post-exercise oxygen consumption (EPOC). Large/highly significant correlations were found between CJ30s and WAnT EPOCs (r = 0.730, P = 0.003), and BLs (r = 0.713, P = 0.009). Moderate/significant correlations were found between CJ30s and WAnT FIs (r = 0.640, P = 0.014), CJ30s first four jumps mean JH and WAnT peak P (r = 0.572, P = 0.032), and CJ30s mean JH and WAnT mean P (r = 0.589, P = 0.021). CJ30s showed excellent and moderate reliability (ICC) for AP (maximal JH 0.884, mean JH 0.742, FI 0.657, BL 0.653) and AC (EPOC 0.788), respectively. Correlations observed especially in terms of AC between CJ30s and WAnT provide evidence that former may adequately assess anaerobic performance for the young combat athlete. CJ30 is a reliable test and allow an easy assessment of AP and AC in karate children.

Effect of fatigue caused by a simulated handball game on ball throwing velocity, shoulder muscle strength and balance ratio: a prospective study

BACKGROUND

Arm throwing represents a deciding element in handball. Ball velocity, aim accuracy, and dynamic stability of the shoulder are factors that influence throwing effectiveness. The purpose of this study was to examine the influence of muscle fatigue caused by simulated game activities (SGA) on shoulder rotational isokinetic muscle strength, muscle balance and throwing performance, and to examine the relationship between muscle strength and throwing performance.

METHODS

Ten national elite adult handball athletes were evaluated. Isokinetic internal (IR), external (ER) rotators peak torque, and balance ratio were measured before and after SGA. Ball throwing velocity was assessed by radar gun.

RESULTS

Both internal (IR) and external (ER) rotators peak torque were significantly lower after SGA (p = 0.0003 and p = 0.02, respectively). However, the deleterious effect was more evident for IR than ER muscles (effect size r = 0.39 and r = 0.18, respectively). Balance ratio before and after SGA did not differ (p = 0.06). Ball throwing velocity was not impaired by SGA. Moreover, isokinetic variables correlated positively with ball velocity (r ≥ 0.67).

CONCLUSIONS

SGA affected the muscle strength of IR more than ER, predisposing the shoulder joint to muscular imbalance. The muscular impairment after SGA was insufficient to impair ball throwing velocity.