Mackala K.,University School of Physical Education in Wroclaw |
Fostiak M.,University of Gdansk
Journal of Strength and Conditioning Research | Year: 2015
The purpose of this study was to examine the effect of a short high-intensity plyometric program on the improvement of explosive power of lower extremities and sprint performance as well as changes in sprinting stride variability in male sprinters. Fourteen healthy male sprinters (mean ± SD: age: 18.07 ± 0.73 years, body mass: 73 ± 9.14 kg, height: 180.57 ± 8.16 cm, and best 100 m: 10.89 ± 0.23) participated in the experiment. The experimental protocol included vertical jumping such as squat jump, countermovement jump, and horizontal jumps; standing long jump and standing triple jumps to assess lower-body power, maximal running velocity; a 20-m flying start sprint that evaluated variability of 10 running steps and 60-m starting block sprint. All analyzed parameters were obtained using the new technology of OptoJump-Microgate (OptoJump, Italy). The short-term plyometric training program significantly increased the explosive power of lower extremities, both vertical and horizontal jumping improvement. However, the vertical jumps increased much more than the horizontal. The 20-m improvements were derived from an increase of stride frequency from 4.31 to 4.39 Hz because of a decrease of ground contact time from 138 to 133 milliseconds. This did not translate into step length changes. Therefore, the significantly increased frequency of stride (1.8%), which is a specific expression of ground contact time reduction during support phase, resulted in an increase of speed. The training volume of 2 weeks (with 6 sessions) using high-intensity (between 180 and 250 jumps per session) plyometric exercises can be recommended as the short-term strategy that will optimize one's probability of reaching strong improvements in explosive power and sprint velocity performance. © 2015 National Strength and Conditioning Association.
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.
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.
Stachon A.J.,University School of Physical Education in Wroclaw
Przeglad Menopauzalny | Year: 2013
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.
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.