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Coh I.,University of Ljubljana | Mackala K.,University School of Physical Education in Wroclaw
Journal of Strength and Conditioning Research | Year: 2013

The aim of this study was to examine the relationship between selected variables of lower extremities explosive power measured via countermovement jump (CMJ) and drop jump (DJ) and sprinting ability over 60-and 100-m dash. Twelve national-level Slovenian sprinters were assigned to 2 groups: elite (n = 6) and subelite (n = 6). The grouping criterion was performance in 60 and 100 m in official competition. Biomechanical parameters of both jumps were measured with the use of bipedal force platform and a system of 9 infraspectral charge-coupled device (CCD) cameras with a 200 Hz frequency. Differences between the groups of sprinters were examined with the use of repeated-measures analysis of variance. In CMJ, the differences (p , 0.05) between the groups were revealed in take off velocity (elites = 3.23 ms21, subelites = 2.94 ms21), height of the jump, vertical velocity of body center of gravity, and the impulse of force in the concentric phase of the jump (concentric impulse: elites = 123.91 Ns; subelites = 108.06 Ns). In the DJ, elite and subelite sprinters differentiated in the realization of movement velocity in the eccentric and concentric phases (take off velocity: elites = 3.18 ms21, subelites = 2.87 ms21; eccentric velocity: elites = 3.05 ms21, subelites = 2.81 ms21). This investigation provides evidence that vertical jumps and DJs are very important tools to meet the demands of sprint training according eccentric-concentric muscular work. The DJ showed better quality than CMJ in the neuromuscular specificity. © 2013 National Strength and Conditioning Association.

Malina R.M.,University of Texas at Austin | Malina R.M.,Tarleton State University | Malina R.M.,University School of Physical Education in Wroclaw | Malina R.M.,Liverpool John Moores University
Sports Medicine | Year: 2011

Problems with accurate chronological age (CA) reporting occur on a more or less regular basis in youth sports. As a result, there is increasing discussion of age verification. Use of 'bone age' or skeletal age (SA) for the purpose of estimating or verifying CA has been used in medicolegal contexts for many years and also in youth sport competitions. This article reviews the concept of SA, and the three most commonly used methods of assessment. Variation in SA within CA groups among male soccer players and female artistic gymnasts is evaluated relative to the use of SA as a tool for verification of CA. Corresponding data for athletes in several other sports are also summarized. Among adolescent males, a significant number of athletes will be identified as older than a CA cutoff because of advanced skeletal maturation when they in fact have a valid CA. SA assessments of soccer players are comparable to MRI assessments of epiphyseal-diaphyseal union of the distal radius in under-17 soccer players. Both protocols indicate a relatively large number of false negatives among youth players aged 1517 years. Among adolescent females, a significant number of age-eligible artistic gymnasts will be identified as younger than the CA cutoff because of later skeletal maturation when in fact they have a valid CA. There is also the possibility of false positives-identifying gymnasts as younger than the CA cutoff because of late skeletal maturation when they have a valid CA. The risk of false negatives and false positives implies that SA is not a valid indicator of CA. © 2011 Adis Data Information BV. All rights reserved.

Laroche D.P.,University of New Hampshire | Cook S.B.,University of New Hampshire | MacKala K.,University School of Physical Education in Wroclaw
Medicine and Science in Sports and Exercise | Year: 2012

PURPOSE: The aim of the research was to determine how knee extensor strength asymmetry influences gait asymmetry and variability because these gait parameters have been related to mobility and falls in older adults. Methods: Strength of the knee extensors was measured in 24 older women (65-80 yr). Subjects were separated into symmetrical strength (SS, n = 13) and asymmetrical strength (SA, n = 11) groups using an asymmetry cutoff of 20%. Subjects walked at a standard speed of 0.8 m•s and at maximal speed on an instrumented treadmill while kinetic and spatiotemporal gait variables were measured. Gait and strength asymmetry were calculated as the percentage difference between legs and gait variability as the coefficient of variation over 20 sequential steps. Results: SA had greater strength asymmetry (27.4% ± 5.5%) than SS (11.7% ± 5.4%, P < 0.001). Averaged across speeds, SA had greater single-(7.1% vs. 2.5%) and double-limb support time asymmetry (7.0% vs. 4.3%) than SS and greater single-limb support time variability (9.7% vs. 6.6%, all P < 0.05). Group × speed interactions occurred for weight acceptance force variability (P = 0.02) and weight acceptance force asymmetry (P = 0.017) with greater variability at the maximal speed in SA (5.0% ± 2.4% vs. 3.7% ± 1.2%) and greater asymmetry at the maximal speed in SA (6.4% ± 5.3% vs. 2.5% ± 2.3%). Conclusion: Gait variability and asymmetry are greater in older women with strength asymmetry and increase when they walk near their maximal capacities. The maintenance of strength symmetry, or development of symmetry through unilateral exercise, may be beneficial in reducing gait asymmetry, gait variability, and fall risk in older adults. Copyright © 2012 by the American College of Sports Medicine.

Chmura J.,University School of Physical Education in Wroclaw | Nazar K.,Polish Academy of Sciences
International Journal of Psychophysiology | Year: 2010

During aerobic exercise with increasing intensities choice reaction time (CRT) progressively shortens up to 60-80% of maximal workload, and then it rapidly increases. The aim of this study was to determine whether workload associated with the shortest CRT operationally called "the psychomotor fatigue threshold" is related to the metabolic response to exercise. Thirteen male soccer players (aged 23.3 ± 1.0 yrs) participated in this study. Before and after 6 weeks of training in the pre-competition period they underwent treadmill test at 0 grade with running speed increasing every 3 min by 2 km/h starting from 6 km/h until exhaustion. At each stage of exercise CRT, heart rate, respiratory gas exchange and blood lactate [LA] were measured and the workload corresponding to [LA] of 4 mmol/l (OBLA) was recorded. After training, CRT was significantly shortened at rest (from m ± SEM = 345 ± 12 to 317 ± 12 ms) and during exercise (from 304 ± 10 to 285 ± 11 ms at the psychomotor fatigue threshold and from 359 ± 13 to 331 ± 13 ms, p < 0.001at the last stage). Both OBLA and the psychomotor fatigue threshold were shifted towards greater running velocities (by 0.92 ± 0.26 and 0.85 ± 0.22 km/h, respectively). The psychomotor fatigue threshold exceeded OBLA both before and after training. Significant correlations were ascertained between OBLA and psychomotor fatigue threshold (r = 0.97) and between the changes in OBLA occurring during training and those in psychomotor fatigue threshold (r = 0.88). It is concluded that endurance training not only increases exercise tolerance due to its influence on metabolism but also facilitates psychomotor performance during heavy exercise. © 2010 Elsevier B.V. All rights reserved.

Zielinski J.,University School of Physical Education in Wroclaw | Kusy K.,University School of Physical Education in Wroclaw
Journal of Applied Physiology | Year: 2012

The aim of this study was to assess the effect of training loads on metabolic response of purine derivatives in highly trained sprinters (10 men, age range 20-29 yr) in a 1-yr cycle, compared with endurance-training mode in triathletes (10 men, age range 21-28 yr). A four-time measurement of respiratory parameters, plasma hypoxanthine (Hx) concentration, and erythrocyte hypoxanthine-guanine phosphoribosyl transferase (HGPRT) activity was administered in four characteristic training phases (general, specific, competition, and transition). A considerably lower postexercise plasma concentration of Hx in sprinters (8.1-18.0 μmol/l) than in triathletes (14.1-24.9 μmol/l) was demonstrated in all training phases. In both groups, a significant decrease in plasma Hx concentration in the competition phase and a considerable increase in the transition phase were observed. It was found that the resting erythrocyte HGPRT activity increased in the competition period and declined in the transition phase. Sprinters showed higher HGPRT activity (58.5-71.8 nmol IMP·mg Hb -1·h -1) than triathletes (55.8 - 66.6 nmol IMP·mg Hb -1·h -1) in all examinations. The results suggest a more effective use of anaerobic metabolic energy sources induced by sprint training characterized by higher amount of exercise in the anaerobic lactacid and the nonlactacid zone. The changes in plasma Hx concentration and erythrocyte HGPRT activity might serve as sensitive metabolic indicators in the training control, especially in sprint-trained athletes. These parameters may provide information about the energetic status of the muscles in highly trained athletes in which no significant adaptation changes are detected by means of commonly acknowledged biochemical and physiological parameters. Copyright © 2012 the American Physiological Society.

Ignasiak Z.,University School of Physical Education in Wroclaw
Roczniki Państwowego Zakładu Higieny | Year: 2013

Physical activity is considered to be one of the most important determinants of human health. Many authors emphasize the benefits of physical activity for elderly people--its positive influence on the functioning of many organs and systems, development of greater mobility, slowdown of the involution processes, and counteracting the effects of civilization diseases. The aim of this study was to analyze the structure of physical activity in older adults from the Lower Silesian region. The data was collected as part of the PolSenior national program. The subjects were selected randomly in three stages. The analysis was performed on the data from questionnaires filled out by 192 men and 164 women over the age of 65 years living in the Lower Silesian region. The answers were analyzed in categories such as: age (3 groups: 65-74 years, 75-84 years and over 85 years), gender, place of residence (communities up to 20 000 and over 20 000 inhabitants) and social-occupational status (blue-collar and white-collar workers). The survey results were shown in percentage form and concerned the different types of physical activity performed, the most frequent reasons for undertaking physical activity, sports and recreational physical activity during the respondents youth, between 30 and 60 years of age and at present, as well as the constraints and reasons that prevent an active lifestyle. With age the percentage of people who spend their free time actively decreases. In each age group of elderly people men declared a greater need for physical activity than women. The subjects also differed with the urban factor and social-occupational status. Moreover, the results showed that the larger community, the better the condition created for recreation of older adults and the people whose previous profession was not connected with physical work tried to be physically active in various forms more often than ex-manual laborers. It is probable that education significantly influences an active attitude towards one's health and proper lifestyle. Physical activity of seniors as a one of the basic elements of lifestyle is clearly connected with the environment in which older people live.

Background: Hormonal changes in women during the climacteric period, which result from the reduced ovarian function, manifest in various physical and psychological symptoms. The intensity of these signs mostly depends on biological and social factors, however, the sensation of menopausal symptoms varies from person to person and from population to population. It mostly depends on the present level of sex hormones, general biological conditions and women's health. The aim of the cross-sectional study was to determine the course of climacterium in the aspect of frequency of menopausal symptoms in different groups of women. Material and methods: A questionnaire study was conducted in the health care centers during prophylactic medical examinations. Near 900 women aged 40 and over from the south region of Poland were questioned in 2005-2007. Climacteric symptoms were analyzed in groups of women divided depending on the climacterium phase and type of menopause. Both the questionnaire and the study were accepted by the Bioethical Committee of the Jagiellonian University. The following symptoms were analyzed: hectic fever, night sweat, insomnia, restlessness and tantrum, palpitation and chest distress, dizziness and headache, irregular menstruation and dry vagina. Results and conclusions: The frequency of selected menopausal symptoms differs in the successive phases of climacterium as well as in the group of a different type of menopause. Most of climacteric signs appeared more frequently after menopause, especially in women using hormonal supplementation. Presumably, the high intensity of symptoms impelled these women to use hormonal treatment.

Bankosz Z.,University School of Physical Education in Wroclaw
Human Movement | Year: 2012

Purpose. The aim of this study was to evaluate the differences between two groups of table tennis players (differing by their level of play) in terms of the kinesthetic differentiation ability of their so-called spatial component. Methods. The study was conducted using a goniometer which assessed the accuracy of performing an arm movement, specifically, the pronation and supination of the forearm at the elbow. The study analyzed the accuracy rate of performing this movement, where a smaller value indicated a higher level of kinesthetic differentiation ability. Results. In all four tasks, the more advanced (skill-wise) group of players obtained lower arithmetic mean and median values of accuracy than the group that played at a lower skill set. This may suggest the importance of the tested variable as an important component of table tennis. However, the tested groups did not significantly differ from each other in the accuracy of performing the studied movement. Nonetheless, the variability of the accuracy rate of the lower skill level group was considerably larger than the more advanced and skilled group. Conclusions. It can be assumed that the more advanced group is more homogeneous in terms of accuracy production. This could be the result of specific training exercises.

Domaradzki A.,University School of Physical Education in Wroclaw
Human Movement | Year: 2014

Purpose. balance disorders are considered a significant problem in the elderly as they are associated with an increased incidence of falls. In effect, they can lead to numerous injuries, disability, or even death. The aim of this study was to explore the relationships between the risk of falling and various factors (morphology, socioeconomic status, physical fitness, and physical activity level) in adult and elderly women. Methods. The study population sample included 149 women aged 47-89 years living in the province of Lower Silesia, Poland. The women were divided into two age groups of younger (n =83,3cage= 59.09 years) and older (n = 66, xage= 70.77 years) participants. Measures included bMI, marital status, and physical activity, physical fitness, and education levels. Statistical analysis included a chi-squared (%2) test, cluster analysis, logistic regression, and correspondence analysis. Results. bMI and physical fitness were strongly correlated with falls: the higher the bMI (overweight or obese) and the lower physical fitness, the greater the risk of falling. The remaining variables showed a weak relationship with falling. Conclusions. The fall risk of women who are overweight or obese or with a low physical fitness level is approximately 2.5 times higher than those with normal and healthy levels of bMI and physical fitness. The presence of both risk factors increased the likelihood of falling. © 2014 Human Movement.

Bronikowski M.,University School of Physical Education in Wroclaw
Scandinavian journal of public health | Year: 2011

In this paper we evaluate the sustainability of changes of involvement in physical activity. The paper examines the effectiveness of a model aiming at influencing the frequency of leisure time physical activity, physical fitness and body constituency in youth. The baseline of this study was a randomly selected sample of 13 year olds who participated in an intervention programme carried out in three schools in Poznan in 2005-08. From a total of 199 adolescent boys a subsample of 38 individuals from the experimental group and 34 from the control group were followed for 15 months after the interventional programme finished. From 170 girls, a subsample of 33 from the experimental group and 32 girls from the control group were also randomly selected for the follow-up study. Among the variables monitored were: physical fitness, body constituency, and frequency of leisure time physical activity. All the variables were monitored in pre-test, post-test and follow-up examinations. It was established that 15 months after the end of the interventional programme boys and girls from the intervention groups maintained a higher level of leisure time physical activity than their control group peers, and similarly in the case of selected health-related components of physical fitness. No distinctive differences were found in the case of body constituency, though, apart from muscle mass and the sum of skinfolds in girls. The study exposed an increase in leisure time physical activity in time and a positive influence on selected components of health-related variables. The findings confirm the effectiveness of a multi-level intervention programme involving self-determined out-of-school physical activity planning for school-age youths, indicating the importance of personal and social context.

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