In-season resistance training and detraining in professional team handball players

The object of this study was to investigate the changes in physical parameters produced during an in-season resistance training (RT) and detraining (DT, or RT cessation) in 16 high level team handball players (THPs). Apart from normal practice sessions, THPs underwent 12 weeks of RT. Subjects performed 3 sets of 3-6 reps with a load of 70-85% concentric 1 repetition maximum bench press (1RMBP), 3 sets of 3-6 reps with a load of 70-95% of 4 repetition maximum parallel squats (4RMPS), plus vertical jumps and sprints. The 1RMBP, 4RMPS, speed over 30 m (S30), jump (countermovement jump height [CMJ]; CMJ with additional weights [20kg and 40kg], and ball throw velocity (BTv) were tested before the experimental period (T1), after 6 weeks (T2), and after the 12-week experimental period (T3). Immediately after these 12 weeks, THPs started a 7-week DT period, maintained normal practices. The CMJ and the BTv were the only parameters evaluated during DT. The most important gains (p < 0.001) in S30 were obtained between T1-T2 and T1-T3. The BTv improved significantly (p < 0.001) only between T1-T2 and T1-T3. The most relevant increases (p < 0.001) in jumping performance took place between T1-T2 and T1-T3. The 1RMBP showed significant increases (p < 0.001) only between T1-T2 and T1-T3. The 4RMPS increased significantly between all testing trials. After the DT, THPs showed no significant losses in CMJ performance. However, they declined significantly in BTv (p = 0.023). The results suggest that elite THPs can optimize important physical parameters over 12 weeks in-season and that 7 weeks of DT, although insufficient to produce significant decreases in CMJ, are sufficient to induce significant decreases in BTv. It is concluded that after RT cessation THPs reduced BTv performance.     

Fitness profiling in handball: physical and physiological characteristics of elite players

The purpose of this study was to describe the structural and functional characteristics of elite Croatian handball players and to evaluate whether the players in different positional roles have different physical and physiological profiles. According to the positional roles, players were categorized as goalkeepers (n = 13), wing players (n = 26), backcourt players (n = 28) and pivot players (n = 25). The goalkeepers were older (p < 0.01), and the pivot players were more experienced (p < 0.01) than the backcourt players. The wings were the shortest players in the team. The pivots were tallest and heavier than the backcourt and wing players (p < 0.01), whereas the backcourt players were tallest then wings (p < 0.01). Goalkeepers had more body fat than the backcourt and wing players (p < 0.01). The backcourt players had a lower percentage of body fat. The backcourt players were the quickest players in the team when looking at values of maximal running speed on a treadmill. The Goalkeepers were the slowest players in the team (p < 0.01). The best average results concerning maximal heart rate were detected among the backcourt players. There were no statistically significant differences between the players'positions when measuring blood lactate and maximal heart rate. A strong negative correlation was found between body fat and maximal running speed (r = -0.68, p < 0.01). Coaches are able to use this information to determine which type of profile is needed for a specific position. Experienced coaches can used this information in the process of designing a training program to maximize the fitness development of handball players, with one purpose only, to achieve success in handball.     

Effects of localized and general fatigue on static and dynamic postural control in male team handball athletes

In team sports, sensorimotor impairments resulting from previous injuries or muscular fatigue have been suggested to be factors contributing to an increased injury risk. Although it has been widely shown that physical fatigue affects static postural sway, it is still questionable as to what extent these adaptations are relevant for dynamic, sports-related situations. The objective of this study was to determine the effects of whole-body and localized fatigue on postural control in stable and unstable conditions. Nineteen male team handball players were assessed in 2 sessions separated by 1 week. Treadmill running and single-leg step-up exercises were used to induce physical fatigue. The main outcome measures were center of pressure (COP) sway velocity during a single-leg stance on a force plate and maximum reach distances of the star excursion balance test (SEBT). The COP sway velocity increased significantly (p < 0.05) after general (+47%) and localized fatigue (+10%). No fatigue effects were found for the SEBT. There were no significant correlations between COP sway velocity and SEBT mean reach in any condition. The results showed that although fatigue affects static postural control, sensorimotor mechanisms responsible for regaining dynamic balance in healthy athletes seem to remain predominantly intact. Thus, our data indicate that the exclusive use of static postural sway measures might not be sufficient to allow conclusive statements regarding sensorimotor control in the noninjured athlete population.     

Neuromuscular training improves knee kinematics, in particular in valgus aligned adolescent team handball players of both sexes

The purpose of this study was to investigate the effects of added neuromuscular training (NMT), as compared to just regular training (RT), on lower extremity kinematics and single leg stability in adolescent team handball players of both sexes and to investigate whether these effects are more evident in valgus aligned athletes. Eighty adolescent team handball players (NMT: n = 49, RT: n = 31) were tested on knee kinematics in a drop jump and single leg stability in a 1-leg hop test. Based on the initial results in the drop jump test, both groups were subdivided into an above-average valgus aligned (AAVA; NMT: n = 27, RT: n = 22) and a below average valgus aligned (NMT: n = 22, RT: n = 9) group. All groups received 10 weeks of handball training either without (RT) or with in-season NMT. A significant interaction of training and valgus group was found for all absolute and for 2 out of 4 normalized knee distances in the drop jump test (p < 0.024) and for contact time after the first landing (p = 0.029). The AAVA-NMT group showed the largest relative progression (18-37%) for all these parameters. In the 1-leg hop test, a significant effect of NMT compared to RT was found for both legs (p < 0.042). Compared to RT alone, added in-season NMT has the greatest benefits on knee kinematics and single leg stability, in particular in AAVA adolescent team handball players of both sexes. The results of this study suggest that adolescent team handball players of both sexes should be given NMT, 20 minutes twice a week for 10 weeks to improve landing kinematics and single leg stability. "At risk" players with higher initial valgus angles will benefit most from this NMT.     

The influence of basic body and hand anthropometry on the results of different throwing tests in young handball and basketball players

The aim of this study was to investigate the relationships between basic body and specific hand anthropometric parameters with some specific and non-specific throw test results in young male handball and basketball players. The subjects included 34 handball and 38 basketball players of the 10-11 years old age group, 39 handball and 22 basketball players of the 12-13 years old age group and 39 handball players of the 14-15 years old age group. Body height and body mass, arms' span, height with outstretched hands and sitting height were the basic anthropometric parameters to be measured. For hand anthropometry, 15 specific hand parameters were measured using the method presented by Visnapuu & Jürim?e (2007). Stepwise multiple regression analysis indicated that medicine ball throw results in the youngest age group are highly dependent on the body height (handball players) and body mass (basketball players). In the middle age group, the most important parameter from the hand anthropometry is TL (handball) or height with outstretched hands (basketball). In the oldest group of handball players, the medicine ball throw results were dependent on the P2 from hand anthropometry and sitting height. Quite different anthropometric parameters appeared to influence the handball or basketball throw results. In the youngest age group, most important were body height (handball) or LFL (basketball). In the middle age group, the most important was height with outstretched hands and in the oldest handball players LFL and sitting height. Handball or basketball pass on speed depended on the combination of body mass and FS5 and body height with height with outstretched hands (even 61.40%, R2 x 100) in the oldest age group. The results of passing the handball or basketball on precision were dependent on body height and P3 or P1 among basketball players in the youngest group. In the middle age group the combination of FS3 and body mass and LFL and height with outstretched hands were the most influential. Anthropometric parameters influence on the passing of the ball on speed or precision is lower in handball players compared with basketball players. Our conclusion is that the basic anthropometric parameters are slightly more important than hand anthropometry that influenced different throw tests results in young handball and basketball players.     

Morphological, motor and situation-motor characteristics of elite female handball players according to playing performance and position

The aim of the study was to define biomotor characteristics that determine playing performance and position in female handball. A battery of 13 variables consisting of somatotype components (3 variables), basic motor abilities (5 variables) and specific motor abilities (5 variables) were applied in a sample of 52 elite female handball players. Differences in biomotor characteristics according to playing performance and position of female handball players were determined by use of the analysis of variance (ANOVA) and discriminative analysis. Study results showed the high-quality female handball players to predominantly differ from the less successful ones in the specific factor of throw strength and basic dash factor, followed by the specific abilities of movement without and with ball, basic coordination/agility and specific ability of ball manipulation, and a more pronounced mesomorphic component. Results also revealed the wing players to be superior in the speed of movement frequency (psychomotor speed), run (explosive strength) and speed of movement with ball as compared with players at other playing positions. Also, endomorphic component was less pronounced in players at the wing and back player positions as compared with goalkeeper and pivot positions, where endomorphic component was considerably more pronounced.     

Tooth use and the physical properties of food

For decades, natural historians and comparative anatomists have acknowledged the form/function relationship between an animal's dentition and its food. Historically, anthropologists have cited this relationship to explain adaptations observed in modern species as well as to infer the diets of extinct animals found in the fossil record. Anthropologists have described morphological differences between species that permit dietary niche partitioning which allows closely related primates to co-exist within a single ecosystem. For example, Robinson¹ postulated that the anatomical differences between Australopithecus and Paranthropus are the result of their adaptations to different diets. Jolly's² seed-eating hypothesis suggested that early hominids' morphological divergence from apes resulted from their specialized feeding on small and hard grass seeds. Early work by Kay³ suggested that Sivapithecus' thick molar enamel was an adaptation to habitually eating resistant food items such as hard nuts or seeds enclosed in tough pods.     

Ensuring the appropriate use of genetic tests

Ensuring the correct use of genetic tests is an important challenge for health-policy makers. Many new genetic tests will identify susceptibility to common diseases or adverse drug responses. Some will lead to new prevention opportunities, but others will have minimal clinical value. Statutory regulation alone cannot guarantee appropriate use. Other strategies, including resource allocation and matters related to clinical governance - such as practice-guideline development and health-provider education - are also important.     

Reliability of selected physical performance tests in young adult women

The purposes of this investigation were to establish the reliability of selected physical performance tests in women athletes and nonathletes and to determine performance differences between groups. Fifty women (25 athletes, 25 nonathletes) performed 5 tests in 2 sessions. The performance tests included the figure-eight hop test, up-and-down hop test, side-to-side hop test, hexagon hop test, and zigzag run test. Intraclass correlation coefficients (ICC [2, 1]) were calculated for trial-to-trial, intertester, and day-to-day reliability. Independent t-tests with Bonferroni adjustment (alpha = 0.01) were used for each individual test to compare differences between groups. All tests showed good reliability values (ICC > or = 0.76) in the nonathlete group for all conditions and varied reliability values (0.48-0.99) among conditions in the athlete group. The independent t-tests showed a statistically significant group effect (t > or = 3.041; p < or = 0.004) for all tests. The results showed that these physical performance tests are reliable measurement tools in the female population.     

Monitoring the environment: The use of electronic meters and chemical or bacteriological tests

Following a previous paper which described the characteristics of the various types of electronic ‘environmental meters’ for use in schools this paper aims to give a more critical review of the instruments available. Chemical test papers and kits for use in environmental studies are also described.     

Heterozygosity and extra-pair paternity: biased tests result from the use of shared markers

Recent studies of extra-pair paternity have found support for the idea that heterozygous males have an advantage in siring offspring. Most studies use DNA microsatellite loci to determine paternity and then use the same loci to estimate individual heterozygosity. However, because the likelihood of detecting extra-pair offspring depends on the combinations of parental alleles, it is possible that biases arise from particular allele combinations. This might produce false support for the influence of heterozygosity on mating behaviour. We used a simulation model to assess how large this bias might be. We found two sources of bias. First, we found a bias in the null hypothesis of a simple statistical test commonly used to test several predictions of the heterozygosity hypothesis. The use of randomization tests could eliminate this bias. Second, we found that using the same loci for both paternity and heterozygosity can cause an increase in results supporting the heterozygosity hypothesis when no effect of heterozygosity actually exists. This bias is reduced through the use of more markers with higher levels of polymorphism and heterozygosity, but can be eliminated entirely by using a separate set of markers to determine paternity and assess heterozygosity. The two sources of bias reduce evidence favouring the heterozygosity hypothesis, but do not negate all of the studies that support it. We suggest that further studies of heterozygosity and extra-pair paternity are important and likely to be informative, but our recommendations should be incorporated by researchers to improve the reliability of their conclusions.     

Spontaneous motor activity and physical endurance of rats during acute radiation sickness developing against a background of the use of a radioprotective agent

Cystamine given to rats prior to irradiation with a dose of 8 Gy (LD77/30) ameliorates significantly the severity of radiation sickness and restores spontaneous motor activity by the time of clinical recovery. However, movements that require physical efforts as well as physical endurance remain decreased.