Jiri Balas

Jiri Balas
Charles University in Prague | CUNI

PhD

About

59
Publications
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592
Citations

Publications

Publications (59)
Article
Full-text available
Purpose: Sport climbing is a technical, self-paced sport, and the workload is highly variable and mainly localized to the forearm flexors. It has not proved effective to control intensity using measures typical of other sports, such as gas exchange thresholds, heart rate, or blood lactate. Therefore, the purposes of the study were to (1) determine...
Article
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High-intensity training (HIT) is known to have deteriorating effects on performance which manifest in various physiological changes such as lowered force production and oxidative capacity. However, the effect of HIT in climbing on finger flexor performance has not been investigated yet. Twenty-one climbers partook in an intervention study with thre...
Article
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Purpose: Sport climbing requires high-intensity finger flexor contractions, along with a substantial whole-body systemic oxygen uptake ([Formula: see text]O2) contribution. Although fatigue is often localised to the finger flexors, the role of systemic ̇[Formula: see text]O2 and local aerobic mechanisms in climbing performance remains unclear. As...
Article
Purpose: To examine the validity and reliability of a battery of 10 measures designed to assess the key physiological parameters for successful rock climbing performance. Methods: In phase 1 of the research, an expert panel, using the Delphi method, established a 10-item test battery based on the key determinants of climbing performance. In phas...
Article
It is possible that during resistance training, a weak link in the kinetic chain could possibly result in under-stimulated prime movers. Since grip strength can be a limiting factor during multiple sets of various pulling exercises such as deadlifts, it is important to determine how lifting straps can affect mechanical performance, grip strength, p...
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The purpose of the study was to compare the psychophysiological response of climbers of a range of abilities (lower grade to advanced) when ascending identical climbing routes on a climbing wall and a rotating treadwall. Twenty-two female climbers (31.2 ± 9.4 years; 60.5 ± 6.5 kg; 168.6 ± 5.7 cm) completed two identical 18 m climbing trials (graded...
Article
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Background: This study aimed to compare the effect of traditional and stability-oriented strength exercises on trunk stability and deep stabilization system (DSS) activation in elite futsal players. Methods: Twenty elite futsal players (21-34 years, 180 ± 13 cm, 79 ± 15 kg) were randomly divided into a group that performed stability-oriented exe...
Article
Anthocyanin-rich New Zealand blackcurrant (NZBC) may improve forearm muscle oxygenation and enhance performance in high-level rock climbers. As such, using a double-blind, randomised, cross-over design study, twelve participants performed an oxidative capacity assessment, and two successive exhaustive exercise trials (submaximal forearm muscle cont...
Article
The objective of the current study was to assess the reliability of paddling tests involving pivot turns and their relationship to performance level in elite slalom canoeists. Eighteen elite (national level, N = 9) and high performing elite (HPE – international level, N = 9) slalom canoeists performed timed paddling tests with a different number of...
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PurposeThe purpose of this study was to examine differences in perceived exertion (RPE) and physiological responses for climbers of different abilities completing an identical route low and high above the ground.Materials and Methods Forty-two male (N = 18) and female (N = 24) sport climbers divided into three groups, lower-grade (N = 14), intermed...
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The purpose of the present study was to assess the effect of different water immersion temperatures on handgrip performance and haemodynamic changes in the forearm flexors of males and females. Twenty-nine rock-climbers performed three repeated intermittent handgrip contractions to failure with 20 min recovery on three separate laboratory visits. F...
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Purpose: An advanced system for the assessment of climbing-specific performance was developed and used to: (a) investigate the effect of arm fixation (AF) on construct validity evidence and reliability of climbing-specific finger-strength measurement; (b) assess reliability of finger-strength and endurance measurements; and (c) evaluate the relati...
Article
Purpose: The aim of this study was to determine the effect of two cold water immersion (CWI) temperatures (15° C and 8° C) on repeat handgrip performance to failure. Methods: Thirty-two participants completed three intermittent trials to failure on a climbing-specific handgrip dynamometer on three laboratory visits. For each visit a different re...
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The aim of the study was to determine the reliability of parkour skills assessment in field conditions. Twenty young men completed three trials of a parkour obstacle course on two separate days. The tested group consisted of 10 beginners (age 16 ± 1 years, body mass = 65 ± 12 kg, height = 177 ± 7 cm) and 10 advanced traceurs (age 18 ± 2 years, body...
Article
Basis: For several years, new training tools and methods with preventive anti-injury effect are introduced in sport practice. Unstable platforms and balance tools that were formerly used only in rehabilitation also belong to them. Their use is being dramatically broadened in the last decade and at present they are commonly used to improve the activ...
Article
Baláš, J, Kodejška, J, Krupková, D, Hannsmann, J, and Fryer, S. Reliability of near-infrared spectroscopy for measuring intermittent handgrip contractions in sport climbers. J Strength Cond Res 32(2): 494-501, 2018-The use of near-infrared spectroscopy (NIRS) to investigate muscle oxygenation changes during physical tasks such as rock climbing has...
Article
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Background Many children become less active as they age which increases their risk of developing of chronic conditions. Traditional forms of physical activity may not be optimal for them. There is a need for more attractive form of training to try and increase physical activity levels and improve the fitness of children. The aim of this study was t...
Article
This study examined differences in the oxygenation kinetics and strength and endurance characteristics of boulderers and lead sport climbers. Using near infrared spectroscopy, 13-boulderers, 10-lead climbers, and 10-controls completed assessments of oxidative capacity index and muscle oxygen consumption (mV˙O2) in the flexor digitorum profundus (FD...
Article
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Objective The aim of the study was to determine electromyographic activity of the scapula stabilizing muscles in naturally chosen and corrected shoulder positions in typical static climbing postures. Methods Six male participants undertook surface electromyography measurement in four climbing postures for two different shoulder positions. The acti...
Article
Background: The purpose of this study was to analyse the extent to which minimal dose strength training would elicit improvements in running performance for female recreational runners. Methods: Forty-one female recreational runners were randomly assigned to one of three groups (endurance running [E] n=14; combined endurance running and strength...
Article
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Cíl. Cílem studie bylo objasnit vztah síly pletence ramenního a flexorů prstů k lezeckému výkonu u sportovních lezkyň. Metody. Dvacet jedna žen se zúčastnilo šesti lezeckých testů zaměřených na sílu flexorů prstů a pletence ramenního: vis na liště, maximální síla v otevřeném úchopu, výdrž ve shybu na jedné ruce, výdrž ve shybu na obou rukách, diago...
Article
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The aim of this study was to examine the effect of alterations in potential lead fall distance on the hormonal responses of rock climbers. Nine advanced female climbers completed two routes whilst clipping all (PRO-all) or half (PRO-½) of the fixed points of protection. Venous blood samples were analysed for total catecholamines, noradrenaline (nor...
Article
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Background. Bouldering and lead climbing are divergent disciplines of the sport of rock climbing. Bouldering moves are short and powerful, whilst sport climbing is longer and require a greater degree of endurance. Aim. The aim of this study was to compare forearm muscle oxygenation during sustained isometric contraction between lead climbers (LC) a...
Article
The research base for rock climbing has expanded substantially in the past three decades as worldwide interest in the sport has grown. An important trigger for the increasing research attention has been the transition of the sport to a competitive as well as recreational activity and the potential inclusion of sport climbing in the Olympic schedule...
Article
Basis: Unstable platforms and suspension systems were formerly used exclusively in rehabilitation process. However, their use became regular part of sport preparation also in healthy sportsmen in recent times. Number of sportsmen incorrectly assume that the use of unstable platform or suspension system alone automatically ensures the effective acti...
Article
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This study aimed to (1) evaluate the effect of hand shaking during recovery phases of intermittent testing on the time–forcecharacteristics of performance and muscle oxygenation, and (2) assess inter-individual variability in the time to achieve thetarget force during intermittent testing in rock climbers. Twenty-two participants undertook three fi...
Article
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The aim of this current study was to assess the segmental fluid distribution, grip strength and injury occurrence in elite slalom kayakers and canoeists. Ninety three world--cup competitors (72 males; 21 females) took part in the study. Impedance analysis assessed segmental fluid asymmetry and a questionnaire evaluated injury occurrence during the...
Article
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The aim of the study was to assess the effects of climbing ability and slope inclination on vertical loading both in terms the forces involved and physiological responses. Five novice and six intermediate female climbers completed a climbing route at three slope inclinations (85°, 90°, and 98°). The vertical loading during the climb was assessed by...
Article
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The aim of this study was to assess the validity and reliability of four climbing grip positions during finger flexor strength measurement using electronic scales in sport climbing contexts. Fifty-five climbers with self-reported climbing abilities RP (redpoint) between V and XII– on the Union Internationale des Associations d'Alpinisme scale volun...
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The study aimed to assess the physiological demands of indoor wall climbing in children. Twenty-five children (aged 8–12 years) from a climbing school, with a performance RP (red point) of IV to V+ UIAA (Union Internationale des Associations d'Alpinisme) scale (5.4 to 5.7 YDS [Yosemite Decimal System] and 4a to 5a Sport/French scale), participated...
Article
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The aim of the study was to evaluate the validity and reliability of different arm positions for finger flexor strength measurement in sport climbers. Forty six climbers completed finger flexor strength measurement on a climbing specific device with four different arm positions: 1 - handgrip, shoulder flexed at 0°, elbow fully extended; 2 - shoulde...
Article
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Aim: The aim of this study was to examine the relationship between submaximal and maximal physiological responses to rock climbing for climbers of differing abilities. Methods: Twenty-six male climbers performed a submaximal climbing test on a known circuit at 90° (vertical) and 105° (15° overhanging) inclination and speed 25 movements · min(-1)...
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Laboratoř sportovní motoriky a katedra sportů v přírodě Univerzita Karlova v Praze, Fakulta tělesné výchovy a sportu SOUHRN Cílem studie bylo posoudit efekt doby zatížení a odpočinku na intermitentní lezec-ký výkon do vyčerpání. Metody: Patnáct lezců se zúčastnilo experimentu, ve kterém podstoupili tři typy lezeckých zatížení do vyčerpání: kontinuá...
Article
Basis: Muscle asymmetry is used as an indicator of overload in sport training, associated with injury incidence. Aim of the work was to assess the correlation of injuries with unilateral functional asymmetry of forearm muscles in sport climbers. Methods: 24 elite sport climbers were tested. The group was deliberately selected in a way that 12 climb...
Article
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Abstract Issues of high levels of muscular asymmetry have been associated with injury risk, and therefore have potential implications for decremental performance at the elite sport level. The aim of this current study was to assess the relationship between the segmental fluid distribution and the paddle grip in elite male and female slalom kayakers...
Article
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Cílem práce bylo posoudit zájem o pohybové aktivity studentů prvních ročníků na 2. a 3. lékařské fakultě (LF) UK. Dotazníkové šetření bylo prováděno na souboru 407 studentů, kdy 182 studentů bylo z 2. LF UK a 225 studentů z 3. LF UK. Studenti obou fakult (2. a 3. LF) sportují nejčastěji do dvou hodin týdně (37 %, respektive 38 %) a dvě až čtyři hod...
Article
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Práce se zabývá porovnáním a ověřením účinnosti didaktického programu cvičení na labilních a stabilních plochách pro stimulaci silových schopností. Experimentální studie se zúčastnilo 50 rekreačních sportovců, kteří byli náhodně rozděleni do skupin se silovým programem na labilních nebo stabilních plochách. Pohybový program trval 10 týdnů a obsahov...
Article
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The aims of this study were to examine training characteristics, body composition, muscular strength, and endurance in sport climbers, and to demonstrate the relationship among these components by means of structural equation modelling. Altogether, 205 sport climbers (136 males, 69 females), with a performance RP (red point) of grade 4 to 11 on the...
Article
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The aim of the study was to propose and verify the climbing test with increasing speed on the overhanging wall to determine the maximal sport specific oxygen uptake (VO2max). Fourteen female climbers with a climbing ability ranging from 3 to 10 UIAAscale (Union Internationale des Associations d’Alpinisme) took part in the study. The test started at...
Article
Basis: Isokinetic dynamo-meter is used to both rehabilitation procedures and diagnostics of actual state of muscle apparatus. The strength in knee extension and flexion is mostly measured. Despite the fact that methodology of measurement of muscle strength of extensors and flexors via isokinetic dynamometer is known for quite a long time, its relia...
Article
The issue of the strength training effectiveness is getting in the foreground of sport preparation. Recently, the stimulation of strength abilities and deep stabilisation system (further DSS) via the unstable platforms starts to be promoted. Aim of our work is to confirm the effectiveness of strength training in the dynamic and static regime on uns...
Article
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Cílem této studie bylo určení reliability měření maximální volní kontrakce na izometrickém dynamometru Vishay Tedea-Huntleigh Model 1042 ve vybraných kloubech horních a dolních končetin při flexi a extenzi. Měření bylo prováděno ve dvou dnech s 48h odpočinkem na skupině 20 studentů (6 žen, 25,0 ± 2,3 let; 14 mužů, 24,4 ± 2,7 let). Reliabilita byla...
Article
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Sportovní lezení je v současné době chápáno částí lezecké populace jako zajímavý kondiční prostředek. Předložená studie objasňuje vztah mezi vybranými kondičními testy, anamnetickými údaji a sportovním výkonem v lezení ve smyslu přelezení cest OS nebo RP a vzájemně poukazuje na vztah mezi těmito způsoby přelezů lezeckých cest. Studie popisuje vztah...
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BACKGROUND: In sport and in top performance sport in particular, the continuous monitoring of body compo-sition (BC) may regulate the training process, aff ecting positively athletesʼ top form. BC is, therefore, considered to be one of the components of the physical fi tness of athletes. Research studies dealing with BC in women volleyball players...
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The aim of the study was to compare the effect of four recovery methods (PAS – passive, ACT – active, CW – cold water, CWW – cold and warm water) on repeated climbing performance. Five advanced climbers (mean age 28.6, s = 4.0 years) performed, in a random crossover design, 4 sessions with 3 repeated climbing tests to exhaustion. The effect of the...
Article
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The aim of this study was to investigate whether climbing in children leads to the development of upper limb strength and endurance, and changes in body composition. Fifty young climbers aged 10–17 participated in an 8 week climbing program. Metres climbed were used as a factor to assess the effect of climbing. Two groups were ex post formed with a...

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Projects (3)
Project
The project aims to develop a methodology for a comprehensive assessment of sport-specific finger strength and endurance in rock climbing. A combination of strength and muscular endurance tests and a specifically developed strength measuring device with real time feedback are used to evaluate both physical qualities and physiological functions (i.e. the level of local forearm aerobic and anaerobic capacity). This approach would be more helpful for optimizing the training process and may be applied in other sports where peripheral factors are of high importance.
Project
To clarify in seniors relations between the factors: frequency and intensity of PA, nutrition and the health state, anthropometric data, incidence of muscle weakness and obesity and the quality of life. To verify efficiency of exercise programs in the area of the lifestyle and the quality of life.
Project
In 2014 the International Rock Climbing Association agreed to develop a multi-centre trial as an investigation in the sport-specific measurement and evaluation tools for the sport of rock climbing. A battery of 10 tests were developed for validation and reliability assessment. Seven research centres, in Austria, Chile, Czech Republic, France, New Zealand, Spain and United Kingdom are involved in the study. The initial results for the study were presented at the 2016 IRCRA Congress in telluride, CO, USA. Details of the research can be found at www.ircra.rocks.