Wyniki wyszukiwania - Biblioteka Nauki

1

Doping in recreation: public view versus declared use of AAS among people practising various sports (a study of Poznan gyms and fitness clubs patrons)

100%

Posiadala D. , Smorawinski J. , Pluta B. , Andrzejewski M.

Studies in Physical Culture and Tourism

|

2010

|

tom 17

|

nr 3

2

Sport communities and organizations as sources of anti-doping education and places of interest development of students of University School of Physical Education in Poznan

100%

Posiadala D. , Smorawinski J. , Pluta B. , Andrzejewski M.

Studies in Physical Culture and Tourism

|

2009

|

tom 16

|

nr 3

3

Cardiovascular and neurohormonal responses to lower body negative pressure [LBNP]: effect of training and 3 day bed rest

63%

Gasiorowska A. , Mikulski T. , Smorawinski J. , Kaciuba-Uscilko H. , Cybulski G. , Zieba A. W. , Krzeminski K. , Niewiadomski W. , Nazar K.

|

tom 57

|

nr 10

85-100

EN

Both intensive training and bed confinement impair orthostatic tolerance, however, moderate training may exert beneficial effect on cardiovascular adjustment to gravitational stimuli. It was hypothesized that moderate training attenuates effects of bed rest. To test this assumption 24 healthy male volunteers aged 20.8±0.9 yrs were subjected to 6° head down bed rest (HDBR) for 3 days before and after 6 weeks of moderate endurance training. Before and after HDBR graded LBNP tests (-15, -30, -50 mmHg) were performed. During these tests heart rate (HR), stroke volume (SV), blood pressure (BP), plasma catecholamines, ACTH, adrenomedullin, atrial natriuretic peptide, plasma renin activity (PRA) and hematocrit were determined. HDBR did not systematically influence LBNP tolerance up to -50 mmHg, but it enhanced rates of reduction of SV, cardiac output and systolic BP and increased elevations of HR and PRA. Training did not alter significantly effects of HDBR on LBNP-induced changes in HR, SV, CO and TPR but it attenuated decrease in systolic BP and diminished increases in plasma noradrenaline and PRA. In conclusion, training has negligible effect on the HDBR-induced changes in central hemodynamics during LBNP but may increase vascular sensitivity to some vasoconstricting factors.

4

Effect of 6-week endurance training on hemodynamic and neurohormonal responses to lower body negative pressure (LBNP) in healthy young men

63%

Nazar K. , Gasiorowska A. , Mikulski T. , Cybulski G. , Niewiadomski W. , Smorawinski J. , Krzeminski K. , Ziemba A. W. , Dorsz A. , Kaciuba-Uscilko H.

Journal of Physiology and Pharmacology

|

2006

|

tom 57

|

nr 2

EN

Endurance training is considered as a factor impairing orthostatic tolerance although an improvement and lack of effect have been also reported. The mechanisms of the changes and their relation to initial tolerance of orthostasis are not clear. In the present study, effect of moderate running training on hemodynamic and neurohormonal changes during LBNP, a laboratory test simulating orthostasis, was investigated in subjects with high (HT) and low (LT) tolerance of LBNP. Twenty four male, healthy subjects were submitted to graded LBNP (-15, -30 and -50 mmHg) before and after training. During each test heart rate (HR), stroke volume (SV) and blood pressure, plasma catecholamines, ACTH, adrenomedullin, atrial natriuretic peptide, and renin activity were determined. Basing on initial test, 13 subjects who withstood LBNP at -50 mmHg for 10 min were allocated into HT group and 11 subjects who earlier showed presyncopal symptoms to LT group. Training improved LBNP tolerance in six LT subjects. This was associated with attenuated rate of HR increase and SV decline (before training, at -30 mmHg DHR was 21 ± 4 beats/min and SV – -36± 8 ml while after training the respective values were 8 ± 4 beats/min and -11± 6 ml). No differences in hemodynamic response were found in HT subjects and those from LT group whose LBNP tolerance was unchanged. In neither group training affected neurohormonal changes except inhibition of plasma ACTH rise in subjects with improvement of LBNP tolerance. It is concluded that some subjects with low orthostatic tolerance may benefit from moderate training due to improvement of cardiac function regulation.

5

Effects of three-day bed rest on metabolic, hormonal and circulatory responses to an oral glucose load in endurance or strength trained athletes and untrained subjects

63%

Smorawinski J. , Kaciuba-Uscilko H. , Nazar K. , Kubala P. , Kaminska E. , Ziemba A. W. , Adrian J. , Greenleaf J. E.

|

nr 2

6

Exercise training and 3-day head down bed rest deconditioning: exercise thermoregulation

63%

Smorawinski J. , Mlynarczyk C. , Ziemba A. W. , Mikulski T. , Cybulski G. , Grucza R. , Nazar K. , Kaciuba-Uscilko H. , Greenleaf J. E.

|

nr 1

EN

Bed rest (BR) deconditioning causes excessive increase of exercise core body tempera-ture, while aerobic training improves exercise thermoregulation. The study was designed to determine whether 3 days of 6° head-down bed rest (HDBR) affects body temperature and sweating dynamics during exercise and, if so, whether endurance training before HDBR modifies these responses. Twelve healthy men (20.7±0.9 yrs, VO2max: 46±4 ml·kg-1·min-1) underwent HDBR twice: before and after 6 weeks of endurance training. Before and after HDBR, the subjects performed 45 min sitting cycle exercise at the same workload equal to 60% of VO2max determined before training. During exercise the VO2, HR, tympanic (Ttymp) and skin (Tsk) temperatures were recorded; sweating dynamics was assayed from a ventilated capsule on chest. Training increased VO2max by 12.1% (p<0.001). Resting Ttymp increased only after first HDBR (by 0.22 ± 0.08 °C, p<0.05), while exercise equilibrium levels of Ttymp were increased (p<0.05) by 0.21 ± 0.07 and 0.26 ± 0.08 °C after first and second HDBR, respectively. Exercise mean Tsk tended to be lower after both HDBR periods. Total sweat loss and time-course of sweating responses were similar in all exercise tests. The sweating threshold related to Ttymp was elevated (p<0.05) only after first HDBR. In conclusion: six-week training regimen prevents HDBR-induced elevation of core temperature (Ttymp) at rest but not during ex-ercise. The post-HDBR increases of Ttymp without changes in sweating rate and the tendency for lower Tsk suggest an early (<3d) influence of BR on skin blood flow.

7

Hemodynamic and neuroendocrine predictors of lower body negative pressure (LBNP) intolerance in healthy young men

63%

Gasiorowska A. , Nazar K. , Mikulski T. , Cybulski G. , Niewiadomski W. , Smorawinski J. , Krzeminski K. , Porta S. , Kaciuba-Uscilko H.

Journal of Physiology and Pharmacology

|

2005

|

tom 56

|

nr 2

EN

Exposure to LBNP results in body fluid shift to lower extremities similarly as under influence of orthostatic stress. In susceptible persons it leads to syncope. For better understanding why certain individuals are more susceptible to orthostatic challenges it seemed necessary to collect more data on hemodynamic and neuroendocrine adjustments occurring before onset of presyncopal symptoms Accordingly, in this study heart rate (HR), blood pressure (BP), stroke volume (SV), cardiac output (CO), hematocrit, plasma catecholamines, adrenomedullin, ACTH and plasma renin activity (PRA) were measured in 24 healthy men during graded LBNP (-15, -30 and -50 mmHg). Thirteen subjects completed the test (HT group) whereas 11 had presyncope signs or symptoms at -30 mmHg or at the beginning of -50 mmHg (LT group). Comparison of these groups showed that LT subjects had lower baseline total peripheral resistance and higher plasma adrenomedullin. During LBNP plasma catecholamine and PRA increases were even greater in LT than in HT group while plasma adrenomedullin elevations were similar in both groups. Plasma ACTH increased only in LT group following presyncope symptoms. Low tolerant group showed more rapid decline of SV and CO than HT subjects from the beginning of LBNP. It is suggested that measurements of SV at the level of LBNP which did not evoke any adverse symptoms may be of predictive value for lower orthostatic tolerance.