Relationships between anthropometric and physiological characteristics with throwing velocity and on water jump of female water polo players.

AIM: The aim of this study was to examine the relationship between the anthropometric, the physiological, as well as performance related characteristics of elite female water polo players and the two important technical game parameters such as throwing velocity and on water jump. METHODS: Thirty-three female professional water polo players (age:21.7±5.4 years, height: 171.5±5.8 cm, body mass: 65.5±8.0 Kg) members of the top four teams of the Greek A1 women league were assessed for anthropometric and body composition characteristics, for physiological and performance related characteristics as well as technical characteristics. All tests were completed a month prior to an extremely important sport event. RESULTS: The percentage of body fat was 23.6±7.0 % and lean body mass was 50.0±5.6 kg. VO(2peak) was 47.5±5.8 ml∙kg(-1) ∙min(-1), La (peak) 7.50±1.50 mmol∙l(-1) and the swimming speed at 25-m sprint test as an indicator of the anaerobic power was 1.76±0.1 m∙s(-1). The throwing velocity was 15.54±0.71 m s(-1) and vertical jump on water 61.65±3.68 cm. External-internal rotator muscles torque showed about a 1:1 ratio. Body lengths, swimming speed, internal-external torque of shoulder muscles as well as VO(2) were significantly correlated with ball throwing velocity (r=0.36 to r=0.70, P<0.05). Body composition and swimming speed were associated with the on-water jump (r=0.34 to r=0.72, P<0.05). CONCLUSION: Knowledge of the physiological and anthropometric features that correlate with the two mainly used techniques in water-polo (throwing velocity and on water jump) can be used by coaches to implement effective training programs.

Physiological demands of water polo goalkeeping.

The purpose of this study was to investigate the physiological demands of water polo goalkeepers during competition and to examine whether the playing intensity of the goalkeeper decreases as the game time progresses. During eight official games the following measurements were performed on eight elite water polo goalkeepers: (1) video analysis of activities, (2) monitoring of blood lactate (BLa) and (3) continuous recording of heart rate (HR) responses. Mean HR of total mixed playing time, excluding breaks among quarters, was 134.3+/-20.3bpm for 36 (4x9) min of game duration. The large portion of the game (85.6%) was performed with a HR lower than 151.4+/-2.7bpm (82.1+/-1.4% of HRpeak) an intensity corresponding to the players' anaerobic threshold (3.49+/-0.60mmolL(-1)). However, an important part of the game (14.4%) contained activities with sudden HR increases above the anaerobic threshold. Mean BLa accumulation at the end of each game period was 3.93+/-1.64mmolL(-1). Individual lactate values varied from 2.0 to 8.3mmolL(-1). Goalkeeper exercise intensity reached its peak value (152.5+/-10.1bpm) whenever his team competed with one player less due to player exclusion. No significant differences were found in HR, BLa and the percentage of time spent in each of the activity categories between game periods. In conclusion, goalkeeper's game can be described as of intermittent nature with great variability in the intensity performed. The greater part of the game is associated with a low aerobic demand while an important part of the game contains activities with sudden HR increases above the anaerobic threshold implying also a considerable demand on anaerobic metabolism. The intensity of exercise of the goalkeeper does not differ from period to period.

Effect of dietary carbohydrate content on blood glucose levels of swimmers during training.

AIM: Data, as far as the impact of carbohydrate content of diets on training performance, are limited and conflicting and blood glucose levels during swimming training have never been reported. The purpose of this study was to determine if the type of diet can influence blood glucose levels during a regular swimming training session. METHODS: Twelve elite male swimmers with a mean age of 15.7+/-0.67 years were enrolled for this study. Prior to testing, the swimmers were subjected to: 1) body composition analysis, 2) maximal heart rate determination, and 3) estimation of resting and swimming energy expenditure. Subsequently, swimmers were put on two isocaloric three-day diets, containing either a high percentage of carbohydrate (HCD-65%) or a low percentage of carbohydrate (LCD-35%) before performing the two 110 minutes training sessions (inter-spaced by 6-8 days) at an intensity of 75% of peak heart rates. Blood glucose was collected and analyzed at 0, 20, 60 and 110 minutes of exercise. RESULTS: Blood glucose under both dietary conditions initially dropped and thereafter rose again by the end of the 110 minute training session. The data revealed that blood glucose never dropped to hypoglycemic levels, but showed a different pattern of changes throughout training. CONCLUSION: The carbohydrate content of the diet followed for a period of three days prior to testing, does not appear to directly affect blood glucose levels throughout a swimming training session lasting over 90 minutes, in elite national level swimmers.

The influence of game duration and playing position on intensity of exercise during match-play in elite water polo players.

In this study, we assessed exercise intensity in 20 water polo games of different duration. The hypothesis that right wing players perform at a higher intensity than back and forward central players was also tested. Thirty water polo players, equally split between three field positions, participated in the study. Initially, their performance-related physiological capabilities were evaluated. Subsequently, during water polo games of short (4 x 7-min periods) or long duration (4 x 9-min periods), heart rate was monitored continuously and blood lactate concentration was measured at the end of each period. Activity patterns were also recorded using a video camera. Mean heart rate over the entire game was 156 +/- 18 beats x min(-1). Overall exercise intensity fluctuated around a value corresponding to the lactate threshold (4.03 +/- 0.96 mmol x l(-1), 86 +/- 5% of peak heart rate) and decreased (P < 0.003) with game time (4.22 +/- 1.8 and 3.47 +/- 1.9 mmol x l(-1) in the second and fourth quarter, respectively). During the last 6 min, heart rate was higher (P < 0.001) in games of short duration (156 +/- 3 beats x min(-1)) than in games of long duration (152 +/- 8 beats x min(-1)). Video analysis showed that the percentage of time spent in low-intensity activities (i.e. "out of game") was lower (23 vs. 26%), whereas that in high-intensity activities (i.e. "sprinting crawl") was higher (21 vs. 19%), in games of short compared with long duration. No difference was observed among players of various field positions in any of the variables examined. Thus during match-play, games of long duration produced significantly lower heart rate responses than games of short duration, and the physiological response exhibited by the players was not affected by field position. The water polo authorities should consider these results before changing game duration and coaches should prepare their athletes accordingly.

On-water and dryland vertical jump in water polo players.

AIM: The performance of the vertical jump constitutes a fundamental technical ability in many team sports, including water polo. The purpose of the present study was therefore twofold: firstly, to evaluate the ability of water polo players to move their bodies vertically off the water (on-water vertical jump), and secondly, to determine on the same players their lower bodies' explosive power ability, while performing a vertical jump on dry-land (dry-land vertical jump). We also investigated whether the performance of the on-water vertical jump depends on the position of the players in the game and on competition. METHODS: Forty-three water polo players, were tested on-water and on dry-land. The on-water vertical jump was assessed using a board with a centimeter scale attached on it. A video camera that was placed facing the board was used to record the trials of the players. RESULTS: The mean value of the on-water vertical jump was 68.3+/-4.6 cm, whereas the mean value of the dry-land vertical jump was 49.6+/-6.5 cm. The coefficient between the 2 jumps was very low (r=0.25). Significant differences between the 2 jumps according to the players' positions and to their level of competitiveness were found. CONCLUSIONS: The performance of the on-water vertical jump correlates poorly with the explosive ability of the lower body as that which was assessed by the dry-land vertical jump. Furthermore, the ability to move the body vertically on-water differs significantly among players, depending on their position and on the level of competitiveness.