Wyniki wyszukiwania - Biblioteka Nauki

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Anaerobic performance in 30s Wingate test as one of the possible criteria for selection Czech hockey players into National Hockey League

100%

Heller J. , Vodicka P. , Janek M.

Physical Activity Review

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2019

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nr 7

57-62

EN

The selection into the National Hockey League (NHL) is based on criteria reflecting job analysis of a professional ice hockey player and the requirements of the game. Only few Czech elite ice hockey players succeed to participate in NHL and their number is decreasing in the last decade. Aim of Study: The aim of the study was to find out and evaluate the level of anaerobic readiness of Czech hockey forwards and defenders playing in the NHL and to compare their anaerobic performance with that in elite national hockey players from the Czech extra-league. Material and Methods: Results of 30s Wingate anaerobic test obtained in 26 forwards and 16 defenders, Czech hockey players from the NHL (from 2001/2002 to 2015/2016 seasons) were compared with the reference values of elite Czech ice hockey players. The comparison was based on the mean values, rate of dispersion, and effect sizes were calculated using Cohen's d coefficient. Results: In forwards, both absolute and relative values of peak power (PP) and anaerobic capacity (AnC) found in Czech players in NHL were higher (d>1) than in elite Czech national players. In defenders, only the value of AnC relative to body mass showed small effect (d=0.36), but absolute and relative values of PP and absolute value of AnC were higher (d>1) than in elite Czech national players. Conclusion: The results of the study indicate that anaerobic readiness evaluated by 30s Wingate test may be, besides dominant on-ice skills, one of the criteria for entry to the top ice hockey competition.

2

The Conconi Test - Searching for the Deflection Point

75%

Hnizdil J. , Skopek M. , Nosek M. , Louka O. , Musalek M. , Heller J.

Physical Activity Review

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2019

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nr 7

160-167

EN

The Conconi Test (CT) is an incremental exercise test characterized by stages of equal intensity. For analysis speed (S) and HR (heart rate) are used. The deflection point of the HR/S graph marks the point where the linear relation between S and HR changes to a curvilinear one. As Conconi stated HR at deflection point represents anaerobic threshold (AT) value. Purpose of this study was to extend our previous research dealing with reliability and validity aspects of CT. Material and Methods: During 10 years (2007-2017) we tested 2 500 subjects using Conconi protocol. Tested were mainly football players and smaller number of runners (long distance and cross country) different ages and fitness level. Some subjects were tested repeatedly during the years. Initial speed of the running treadmill test was determined in the range of 10 to 12 km·h-1, according subjects age and fitness level. Speed was increased gradually every 150 m of 0.5 km·h-1 to the maximum speed when further increases were impossible. HR was recorded at every 150 meters. From a graphical representation dependence HR on increasing running speed we tried to find apparent diversion from the curve of linearity, labeled by Conconi as "deflection point" (DP). Simultaneously respiration values were recorded. From these respiration data we determined the ventilatory threshold (VT2) as a metabolic marker of the onset of blood lactate accumulation. Results: We found 6 types of response HR to increasing speed. a) regular DP; b) linear regression r ≥ 0.98 - no DP; c) linear regression r < 0.98 - no DP; d) inversion character of deflection point; e) DP not corresponding with value of ANP; f) more than one DP. As an AT predictor compared with VT2, Conconi test overestimated this value (0.5 km·h-1). Conclusion: Using of Conconi test as a predictor of ANP has a limitation. ANP values determined by CT are overestimated (0.5 km·h-1). Test stability of CT is very low and there is evidence that DP is not 100% repeated physiology phenomena.

3

Estimating Maximal Heart Rate with the ‘220-Age’ Formula in Adolescent Female Volleyball Players: A Preliminary Study

75%

Nikolaidis P. T. , Padulo J. , Chtourou H. , Torres-Luque G. , Afonso J. , Heller J.

Human Movement

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2014

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tom 15

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nr 3

166-170

EN

Purpose. Although maximal heart rate (HRmax) is used widely to assess exercise intensity in training, there are limited data with regards to the validity of age-based prediction equations of HRmax in volleyball players. Therefore, the aim of the present study was to compare the measured-HRmax of two prediction equations (Fox-HRmax = 220 − age and Tanaka-HRmax = 208 − 0.7 × age) in young female volleyball players. Methods. The study involved 47 volleyball players (age 13.39 ± 2.01 years, body mass 54.0 ± 10.8 kg, height 162.7 ± 10.2 cm) who performed a graded exercise field test (20 m shuttle run endurance test) to assess HRmax. Measured-HRmax values were compared with the Fox and Tanaka prediction equations. Results. The results showed that mean scores for HRmax significantly differed between measured and predicted values (p < 0.001, ŋ2 = 0.49). Post-hoc tests revealed that Fox-HRmax overestimated measured-HRmax (mean difference 5.7 bpm; 95% CI [3.0, 8.5]), whereas Tanaka-HRmax was similar to measured-HRmax (-2.2 bpm; 95% CI [-4.9, 0.4]). HRmax did not correlate with age (r = 0.16, p = 0.291). Conclusions. The results of this study failed to validate the widely used ‘220−age’ formula in volleyball players. Coaches and fitness trainers should take into account that the overestimation of HRmax by the Fox equation might lead to prescribing exercise at a higher intensity than what is targeted. Therefore, the Tanaka equation appears to offer a more accurate prediction equation of HRmax than the Fox equation in young female volleyball players.