University School of Physical Education in Wrocław University School of Physical Education in Kraków

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University School of Physical Education in Kraków (Akademia Wychowania Fizycznego im. Bronisława Czecha w Krakowie) Human movement

quarterly

vol. 14, number 2 (June), 2013, pp. 93 – 190

editor-in-Chief alicja Rutkowska-Kucharska

University School of Physical Education, Wrocław, Poland associate editor edward mleczko

University School of Physical Education, Kraków, Poland editorial Board

Physical activity, fitness and health

Wiesław Osiński University School of Physical Education, Poznań, Poland

Applied sport sciences

Zbigniew Trzaskoma Józef Piłsudski University of Physical Education, Warszawa, Poland

Biomechanics and motor control

Tadeusz Bober University School of Physical Education, Wrocław, Poland Kornelia Kulig University of Southern California, Los Angeles, USA

Physiological aspects of sports

Andrzej Suchanowski Medical University of Bialystok, Białystok, Poland

Psychological diagnostics of sport and exercise

Andrzej Szmajke Opole University, Opole, Poland advisory Board

Wojtek J. Chodzko-Zajko University of Illinois, Urbana, Illinois, USA Gudrun Doll-Tepper Free University, Berlin, Germany

Józef Drabik University School of Physical Education and Sport, Gdańsk, Poland Kenneth Hardman University of Worcester, Worcester, United Kingdom

Andrew Hills Queensland University of Technology, Queensland, Australia Zofia Ignasiak University School of Physical Education, Wrocław, Poland Slobodan Jaric University of Delaware, Newark, Delaware, USA

Toivo Jurimae University of Tartu, Tartu, Estonia

Han C.G. Kemper Vrije University, Amsterdam, The Netherlands

Wojciech Lipoński University School of Physical Education, Poznań, Poland Gabriel Łasiński University School of Physical Education, Wrocław, Poland Robert M. Malina University of Texas, Austin, Texas, USA

Melinda M. Manore Oregon State University, Corvallis, Oregon, USA Philip E. Martin Iowa State University, Ames, Iowa, USA Joachim Mester German Sport University, Cologne, Germany Toshio Moritani Kyoto University, Kyoto, Japan

Andrzej Pawłucki University School of Physical Education, Wrocław, Poland John S. Raglin Indiana University, Bloomington, Indiana, USA

Roland Renson Catholic University, Leuven, Belgium

Tadeusz Rychlewski University School of Physical Education, Poznań, Poland James F. Sallis San Diego State University, San Diego, California, USA James S. Skinner Indiana University, Bloomington, Indiana, USA Jerry R. Thomas University of North Texas, Denton, Texas, USA Karl Weber German Sport University, Cologne, Germany Peter Weinberg Hamburg, Germany

Marek Woźniewski University School of Physical Education, Wrocław, Poland Guang Yue Cleveland Clinic Foundation, Cleveland, Ohio, USA

Wladimir M. Zatsiorsky Pennsylvania State University, State College, Pennsylvania, USA Jerzy Żołądź University School of Physical Education, Kraków, Poland

Translation: Michael Antkowiak, Tomasz Skirecki Design: Agnieszka Nyklasz

Copy editor: Beata Irzykowska Statistical editor: Małgorzata Kołodziej

Proofreading: Agnieszka Piasecka

Indexed in: SPORTDiscus, Index Copernicus, Altis, Sponet, Scopus, CAB Abstracts, Global Health 8 pkt wg rankingu Ministerstwa Nauki i Szkolnictwa Wyższego

http://156.17.111.99/hum_mov Editorial Office Dominika Niedźwiedź

51-612 Wrocław, al. Ignacego Jana Paderewskiego 35, Poland, tel. 48 71 347 30 51, hum_mov@awf.wroc.pl

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ChArACTEriSTiCS Of bODy TiSSuE COmpOSiTiOn

AnD funCTiOnAl TrAiTS in juniOr fOOTbAll plAyErS

AnnA burDukiEWiCz *_,_{jAn ChmurA}_,_{jADWiGA piETrASzEWSkA}_,

juSTynA AnDrzEjEWSkA, AlEkSAnDrA STAChOń, jArOSłAW nOSAl

University school of Physical Education, Wrocław, Poland

ABsTRAcT

Purpose. The aim of this study was to examine the body tissue composition and functional traits of young football players. Methods. Analysis was performed on 23 junior football players. Body mass and height were measured. Bioelectrical impedance was used to assess the players’ body composition (fat mass, muscle mass, body cell mass and extracellular mass). The body mass index, body cell mass index and the extracellular mass/body cell mass ratio were also calculated. Functional traits were assessed by a one-on-one football game in an enclosed space with the objective to score the highest number of goals in a timed setting. Measurements of HRrest, HRmax and heart rate reserve were used to evaluate the efficiency of the subjects’ cardiovascular systems.

Results. Insignificant differences in body tissue composition and cardiovascular efficiency were found regardless of what position was played. Overall, forwards were characterised by having the greatest height, the highest level of active body tissue development and the most efficient cardiovascular systems. Defenders were characterised by having larger body build, while midfielders displayed a significantly greater percentage of extracellular mass and EMc in relation to BcM. Conclusions. The results reveal that trends exist in the body tissue composition and cardiovascular efficiency of football players depending on which position they play. These differences reflect the varied physical efforts players perform during a match and should be taken into consideration when designing training programmes.

Key words: body composition, heart rate, football

doi: 10.2478/humo-2013-0010 2013, vol. 14 (2), 96– 101

* corresponding author.

Introduction

The game of football requires players to perform pe-riodically under high intensity by using aerobic energy sources that sometimes involves overloading the neuro-muscular and hormonal systems.The ability of the neuro-muscular system to produce maximum power in the lower extremities is particularly important for foot-ball players, since the ability to produce explosive efforts at maximum power and force together with a high con-traction velocity seems to be one of the main physio-logical features which differentiate players at different training levels [1, 2]. On the other hand, the variation of sprint activity among football players is reflected in the variety of physiological responses players’ bodies produce. Results have shown that high intensity aerobic interval training leads to an increase in VO2max without negative interference effects on strength, jumping ability or sprint performance [3].

One of the most informative and easiest to examine parameters is heart rate, which characterises the effi-ciency of the cardiovascular system [4]. Research has shown that whole-day heart rate monitoring is an ob-jective, unobtrusive method for measuring physical activity at the age of puberty. For athletes in training, these data are commonly collected from the monitoring

of heart rate changes and used to prevent the occurrence of fatigue[5]. It is commonly known that athletes per-forming to a high degree are characterised by an improved lowering of their resting heart rate (HRrest). Further-more, the correlations observed between maximum heart rate (HRmax), reflected as the highest heart rate achieved during exercise, and HRrest have been used to create an index that can compute VO2max [6]. This re-search revealed that the absolute and relative values of maximum heart rate and oxygen absorption were higher in young elite players in comparison to their peers at a lower training level [7]. In amateur football, the re-cording of HR was confirmed to be useful for training purposes and was also applied to characterise metabolic expenditure during physical effort [8].

Furthermore, with regard to young players, the in-fluence of puberty on body height and functional ca-pacity have also been well substantiated. children and youth performing sports, in comparison to their non-exercising peers, displayed greater development of their somatic features, body efficiency and physical fitness [9]. studies performed on pubertal youths indicate that the level of biological maturity influences the variation of development regarding physical efficiency, velocity and strength. The period of greatest body growth is frequently followed by a significant risein static and explosive force development. Analogous changes in VO2max have been found to accompany the pubertal spurt of body height [10]. The application of multiple linear

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regres-sion analysis revealed the existence of a significant re-lationship between maturity advancement, growth and composite football skill scores in a group of football players at the age of puberty [11]. Positive regression co-efficients were obtained for the occurrence of puberty and aerobic resistance. However, the coefficient for body height was negative, indicating the role of a lower centre of gravity in better football skill performance. However, Philippaerts et al. [12] observed that the period during the greatest height spurt coincides with the development of maximum balance ability, explosive force, running speed, upper-body muscular endurance, agility, cardio-respiratory endurance and anaerobic capacity. A pla-teauing of explosive force development, upper-body muscular endurance and running speed was observed after the pubertal height spurt, at which point body flexibility increasingly developed.

Body tissue composition constitutes one of the fac-tors that not only determine athletes’ motor fitness and sport level but also plays a role in training. Moreover, it varies tremendously across individuals in regards to age and body build. In this regard, adolescence is a very important phase in life due to various social factors that adolescents face and the numerous neuro-hormo-nally determined changes that affect body tissue com-position. This includes the influence of growth hormone, which has, among others, been found to be of significant importance in the maturation of lean mass and muscle strength development at puberty and for young adults in general [13]. The results of research also indicate that a relationship exists between fat (determined by anthro-pometric measurement) and the beginning of puberty in both genders. In the case of young football players, development of choice body tissue components (lean tissue) has been noted as the result of improved physical performance [14, 15].

The development of adolescent boys is, in particular, characterised by an overall decrease in fat tissue and increase in BMI, which at this age reflects an increase in lean mass [16]. Youth involvement in sport (e.g. foot-ball) has also been credited in stimulating bone mass development. However, longitudinal research on a cadet football league (youths aged 11–14) did not reveal any acceleration in their morphological development, al-though it was revealed that muscle power, especially agility and coordination, distinguished the young football players from their untrained peers [17]. There-fore, in order further to investigate this issue, this study examined the features of body tissue composition and functional traits of a group of young 2nd_{league football} players.

Material and methods

Twenty-three junior football players playing on a 2nd league team from Wrocław, Poland were recruited. The players’ mean age was 16.2 years ( ± 0.70) and had mean

training period of 7.3 years (± 1.87). The university’s re-search ethics committee approved the study and all par-ticipants provided their written informed consent prior to data collection, which took place at the end of the 2009 competitive season. Information regarding what position they played in was obtained from their coach. Body mass and height were measured and used to calculate body mass index (BMI; body mass [kg]/body height [m]2_{). Body composition was assessed by} bioel-ectrical impendance with a BIA-101/s analyser (tetrapo-lar version, electrodes placed on the hand–foot) inte-grated with Bodyimage 1.31 software (Akern, Italy). Body composition was measured before an exercise test, with fat mass (FM), muscle mass (MM), body cell mass (BcM) and extracellular mass (EcM) recorded. The compo-nents of body composition were expressed in kilograms or percentage of body mass. Body composition meas-urements were used to compute the body cell mass index (BcMI = BcM [kg] / body height [m]2₎_{and the ratio of} EcM/BcM (extracellular mass/body cell mass).

The players’ functional abilities were measured in special test conditions in order to promote high-inten-sity exercise: individual players participated in a three-minute game of one-on-one football within an enclosed, circular cage (a diameter of 500 cm with 250 cm walls) with goals located on both sides (Hattrick cage, Ludus Partner, Poland). The aim of the game was to score the highest number of goals. Resting heart rate (HRrest) was measured prior to the test, while maximum heart rate (HRmax) was measured immediately after each game. Heart rate was monitored and analysed with a short-range telemetry system (Polar Electro Oy, Finland). Heart rate reserve (HRR) was computed by subtracting HRrest from HRmax.

statistica version 9.0 for Windows (statsoft Inc., UsA) was used for statistical analysis. Basic statistical charac-teristics were computed (mean, standard deviation). The shapiro-Wilk’s test was used to evaluate normal distri-bution. One-way between-groups analysis of variance (ANOVA) with Tukey’s post hoc test was used to evalu-ate the variation of the values recorded for body tissue composition and the physiological features among the participants depending on their position (forwards

n = 7, midfielders n = 9, defenders n = 7). statistical significance was set at p 0.05.

Results

The anthropometric characteristics and functional abilities of the football players are presented in Table 1. The shapiro-Wilk’s test indicates that body height and mass and the studied components of body composition and the players’ physiological response present normal distribution. Analysis of variance, applied to evaluate the variation of the analysed features between those play-ing as forwards, midfielders and defenders, did not reveal any statistically significant differences (Tab. 2) except

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A. Burdukiewicz et al., Body composition and functional traits

Table 1. Physical characteristics of the junior football players (N = 23)

Variable Mean sD Body mass (kg) 66.0 5.62 Body height (cm) 173.7 3.69 Fat mass (kg) 10.4 2.64 Body cell mass (kg) 32.6 2.92 Extracellular mass (kg) 22.9 2.25 Muscle mass (kg) 39.7 3.41 Fat mass (%) 15.7 3.29 Body cell mass (%) 49.5 2.90 Extracellular mass (%) 34.8 2.53 Muscle mass (%) 60.3 3.17 BMI (kg ∙ m–2₎ _21.9 _1.36 BcMI (kg ∙ m–2₎ _10.8 _0.88 EcM/BcM 0.7 0.07 HRrest (b ∙ min–1) 78.96 12.05 HRmax (b ∙ min–1) 181.26 10.40 HRR (b ∙ min–1₎ _102.30 _13.43

Table 2. Physical characteristics of the junior football players grouped by playing position (mean ± sD) Variable Playing position p Forwards (n = 7) Midfielders(n = 9) Defenders(n = 7) Body mass (kg) 67.21 ± 5.46 63.77 ± 6.30 67.57 ± 4.58 0.332 Body height (cm) 175.53 ± 2.28 172.67 ± 4.47 173.36 ± 3.54 0.302 Fat mass (kg) 11.39 ± 2.24 9.06 ± 2.37 11.19 ± 2.93 0.140 Body cell mass (kg) 33.51 ± 3.27 31.49 ± 2.95 33.20 ± 2.39 0.333 Extracellular mass (kg) 22.31 ± 2.23 23.22 ± 2.66 23.19 ± 1.86 0.700 Muscle mass (kg) 40.70 ± 3.71 38.36 ± 3.52 40.40 ± 2.79 0.331 Fat mass (%) 16.91 ± 2.76 14.11 ± 3.08 16.40 ± 3.64 0.189 Body cell mass (%) 49.88 ± 2.85 49.49 ± 3.16 49.19 ± 3.02 0.914 Extracellular mass (%) 33.22 ± 2.16* 36.42 ± 1.82 34.38 ± 2.72 0.028 Muscle mass (%) 60.59 ± 2.99 60.29 ± 3.58 59.87 ± 3.25 0.921 BMI (kg ∙ m–2₎ _{21.83 ± 1.69} _{21.40 ± 1.12} _{22.49 ± 1.23} _0.299 BcMI (kg ∙ m–2₎ _{10.89 ± 1.10} _{10.54 ± 0.69} _{11.06 ± 0.90} _0.513 EcM/BcM 0.67 ± 0.07 0.74 ± 0.07 0.70 ± 0.08 0.174 HRrest (b ∙ min–1) 77.14 ± 14.75 77.33 ± 7.43 82.86 ± 14.70 0.612 HRmax (b ∙ min–1) 196.00 ± 11.75 191.33 ± 7.02 193.00 ± 9.61 0.668 HRR (b ∙ min–1₎ _{104.14 ± 17.33} _{101.78 ± 7.85} _{101.14 ± 16.53} _0.914

* significantly different from midfielders (p < 0.05)

for the percentage of extracellular mass between for-wards and midfielders.

The results find that forwards are characterised by the highest body height, body cell mass, muscle mass and fat mass. HRmax and HRR values were also at a high level. Furthermore, forwards displayed the lowest levels of extracellular mass development, EcM/BcM and resting heart rate. Furthermore, the BMI and BcMI in-dices indicate that forwards had the largest body build as well as exhibiting the highest HRmax. When compared

with the other positions, their BcM percentage, muscle mass and heart rate reserve were at lower levels. Overall, midfielders displayed the smallest body size. This group also exhibited the lowest level of body fat and BMI and BcMI values. Their HRmax values were the lowest pared with the other positions. However, when com-pared with forwards and defenders, midfielders were characterised by a significantly greater amount of ex-tracellular body mass and larger values of the EcM/ BcM index.

Discussion

The specificity of modern sport necessitates taking into consideration certain body build predispositions in order to determine what somatic criteria ought to be used when selecting potential athletes in given sport. The optimum adaptation of an athlete to the require-ments of the sport they play in is in large part the result of their morphological structure and a targeted train-ing regimen that modifies selected somatic parameters. For young athletes, in addition to the above factors, puberty also plays a large role in promoting significant changes in body morphology and tissue composition [18]. This period is characterised by an increase in height, mass, lean mass and bone mineral content. When com-pared with girls, the fat content of boys is at a lower level, where this predisposition is also reinforced by the large-scale involvement of young boys in sport. Although the physical load youths undergo depends on the sport, most training is sufficient enough to cause characteristic changes in the development level of various body

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com-position and functional features. For example, a study of young prepubertal football players revealed a decrease in body fat and an increase in lean body and bone min-eral content in comparison with their control group peers [19]. A significant increase in bone mineral content around the femur neck and lumbar spine areas was also observed in male adults practicing recreational foot-ball for many years [20].

When comparing playing positions, body composi-tion analysis on adult football players found observable differences between goalkeepers and outfield players [21]. Regarding youth, all players aside from goalkeepers re-vealed little difference in the development of their body composition. The results indicate that the lowest amount of fat tissue is observed in midfielders, although similar values were noted for forwards and defenders. However, greater variation of fat tissue levels has been revealed in adult players [22]. significantly greater fat mass was discernible in midfielders in comparison with forwards and defenders.

Lean body mass consists of body cell mass, extra-cellular fluid and extraextra-cellular solids [23]. Body cell mass, which is the mass of all metabolically active body cell components, plays a significant role in physical train-ing. chronic diseases such as AIDs, tumours or cancers and the ageing process all result in a decrease of BcM. The metabolic activity of BcM and its significant role in the human body is also evident in how diversified its development is, although depending on the physi-cal activity an individual performs and their training level [24]. The results confirm previous studies that have indicated an insignificant variation in the somatic structure and body composition of outfield players in relation to players in other positions [25]. The largest BcM and muscle mass values are observed in forwards while the lowest in defenders. Melchiorri et al. [26] observed a similar trend by analysing the body compo-sition of two professional male football teams from two different divisions. The higher ranked team displayed significantly lower levels of body fat in its defenders, while higher BcM values were noted among the for-wards from both teams. Players who were individually ranked higher displayed greater cell mass, even though the two teams differed in age, body mass, height and BMI.

The players analysed in this study did not display significant differences in body mass and tissue compo-sition. Previous research has confirmed a correlation between athletes’ BMI and creatinine concentration although this is dependent on the practiced sport, type of training, involvement of aerobic and anaerobic meta-bolism and the length of the competitive season [27]. Nevertheless, other research on athletes of both gen-ders and people with eating disorgen-ders indicated that body cell mass index, in comparison to BMI, is better suited to monitor changes in the amount of muscle mass [28]. This results from the fact that the body cell mass index is more sensitive to changes in the

nutri-tional status of an individual. In the examined group of footballers, the lowest values of both indices were observed in midfielders, while defenders displayed the greatest body mass and cell mass when taking body height into consideration. The obtained results may be further justified by the observed ascendency of the mesomorphic somatotype of defenders [29].

Extracellular mass contains all the metabolically inactive body tissues, and thus an increased EcM/BcM index value is frequently interpreted as a sign of malnu-trition. However, a different trend is observed among football players, who feature a decrease in the relative amount of extracellular mass [30]. This has been linked to physical activity that requires larger power output, such as in endurance running and cross country skiing. In the group of football players examined in this study, the overall EcM/BcM index was found to be 0.7, which corresponds to those values in well-trained adult com-petitors [31]. When considering playing positions, the lowest index value was observed in forwards, while midfielders were characterised by the highest level of extracellular mass in relation to cell mass.

The easiest way to measure the reaction of the cardi-ovascular system to effort is to determine the heart rate index, which has been significantly correlated to VO2max and blood lactate and saliva lactate levels. Heart rate reserve is also used as an indirect measurement of the intensity of metabolic changes and useful when com-paring the endurance of players in different positions on the pitch [32]. The group of youth football players analysed in this study featured no statistically signifi-cant variation between resting heart rate, maximum heart rate or heart rate reserve. However, it should be emphasised that forwards displayed the lowest HRrest and the highest HRmax and HRR during the test. De-fenders were characterised by the highest values of rest-ing heart rate and the lowest values of maximum heart rate and heart rate reserve. Based on the obtained re-sults, it can be concluded that forwards are characterised by the highest level of cardio-vascular efficiency. Research conducted on 14–21 year-old football players revealed that forwards were characterised by greater endurance, velocity, agility and power, along with better muscle de-velopment and body leanness, than other players [33]. Goalkeepers, on the other hand, were characterised with greater height, mass, body fat and the lowest aerobic capacity. Midfielders displayed greater levels of agility and endurance, while defenders were characterised by the lowest body fat.

Conclusions

Analysis of the results revealed that there are certain differentiating trends in body tissue composition and cardiovascular efficiency among football players playing in different positions. Forwards were characterised by having the greatest height, highest levels of active body

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A. Burdukiewicz et al., Body composition and functional traits

tissue development and the most efficient cardiovascular systems. Defenders displayed larger body build, while midfielders were characterised by significantly higher values of extracellular mass and EMc in relation to BcM. These differences reflect the varied physical efforts play-ers perform during a match and should be taken into consideration when designing training programmes. References

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Paper received by the Editors: June 19, 2012 Paper accepted for publication: March 12, 2013

Correspondence address

Anna Burdukiewicz

Akademia Wychowania Fizycznego al. I.J. Paderewskiego 35

51-612 Wrocław, Poland

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GEnDEr-bASED DimOrphiSm Of AErObiC

AnD AnAErObiC CApACiTy AnD phySiCAl ACTiviTy

prEfErEnCES in DEAf ChilDrEn AnD ADOlESCEnTS

AnnA zWiErzChOWSkA

The Jerzy Kukuczka Academy of Physical Education, Katowice, Poland

ABsTRAcT

Purpose. Research on the hearing impaired has revealed that the rate of change of physical fitness characteristics between both genders may be different than that of the hearing. The aim of the study was to verify the gender-based differentiation of aerobic and anaerobic capacity in a group of deaf children and adolescents (aged 10–18 years) and to evaluate their physical activity preferences. Methods. A semi-longitudinal study was conducted, with data collected three times over a period of two years. Aerobic capacity was measured by the PWC170 cycle test, anaerobic capacity by the Wingate test. A questionnaire was

used to evaluate the physical activity preferences and favored leisure activities of the participants. Results. significant gender-based differences were found in the aerobic and anaerobic capacity of the deaf boys and girls. A moderate correlation was noted for leisure time preferences. Conclusions. Deaf children feature no gender-based differences among their physical activity preferences. Environment plays a major role in stimulating the behavior of deaf children and adolescents.

Key words: aerobic and anaerobic capacity, sexual (gender) dimorphism, deafness

doi: 10.2478/humo-2013-0011

2013, vol. 14 (2), 102– 109

Introduction

Disabilities, especially those that affect the musculo-skeletal system, play a large role in reducing physical activity levels. However, often at times individuals with sensory impairments are not perceived as having the same limitations in performing physical activity as those with physical disabilities. This is especially so with hearing impairments, which are usually not regarded as limiting physical activity, although research on this subject has provided contradictory results. Many researchers state that the physical abilities of the deaf are highly differen-tiated and even sometimes lower than those found among an average hearing population [1–5], concluding that this may be the consequence of how physical education is shaped and taught to the deaf. A study by Ellis [6] re-vealed that one of the most important factors motivat-ing deaf youth in performmotivat-ing physical activity is the emotional support and involvement of parents. A similar conclusion was reached by Dummer et al. [2], stating that there are no differences in the motor skills of deaf children and their hearing peers. This group of authors believes that the introduction of early intervention and special education programs already at the preschool age helped bridge any supposed impediment. Moreover, they recognized that environmental factors (type of school, lifestyle, parental attitude as well as their involvement in physical activity, and the availability of free play op-portunities) also play an important role in motor develop-ment. Liberman et al. [4, 7] drew attention to the impor-tance of several environmental factors, in particular on how physical education classes were conducted through the use of special programs and the role of physical edu-cation teachers in providing a behavioral role model

for participation in physical education. An additional factor noticed by auxologists and teachers of the deaf is the difference in interest in various forms of physical activity based on gender, which is believed to be a re-flection of what physical activity can actually be per-formed [2, 8].

Research has confirmed that the gender difference between males and females is already visible at the pre-school age and includes not only interest in various forms of physical activity but also motility [9]. The ontogenetic development of motor and morphological skills has been described as highly variable. Motor skills are largely the result of environmental conditioning, hence dimorphic variation cannot be as clearly defined as in the case of somatic characteristics. Therefore, it is difficult to expect that dimorphic traits in motility would not be present even when a hearing impairment is present. However, a few studies that have been conducted on the hearing impaired found that the rate and pace of characteris-tics that can emerge to differentiate both genders may be different than those among the hearing [3, 10–13]. Among girls, fewer differences were found to exist be-tween those hearing and deaf than in the case of boys. comparative studies on the physical development of deaf boys and girls have revealed significant differences in favor of girls. One of many conclusions reached by such studies was that deaf girls develop physical and motor skills better than boys [10–15]. It was also noted that deaf girls learn new motor skills quicker and show little or no differences when compared with their hear-ing peers than in the case of deaf boys. In contrast, deaf boys often showed significantly greater motor defi-cits than their hearing peers [2]. Haubenstricker and seefeldt’s findings [8] on the hearing helped theorize

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that the ability to learn basic motor skills is more similar between deaf boys and girls than among their hearing peers. Instead, the delay experienced by deaf boys in learning new motor skills may be caused by them pre-senting a physical fitness level lower than among the hearing.

The aim of this study was to verify what gender dif-ferences exist among a group of deaf children and ado-lescents (10–18 years old) in their ability to perform aerobic and anaerobic tasks as well as what their physical activity preferences. In light of the formulated objective, the study was guided by the following research questions:

1. What is the preferred physical activity of deaf male and female youth?

2. Is gender a factor that differentiates the deaf in their ability to perform aerobic and anaerobic tasks?

It was assumed that the preferred physical activity is an important factor differentiating aerobic and anaero-bic exercise capacity.

Material and methods

students attending special education schools for the deaf and hard of hearing from the Polish cities of Kato-wice, Kraków, and Racibórz comprised the target popu-lation. A sample was selected by adopting the criteria used in modern audiology as based on Parving [16]. The main criterion for inclusion was for the student to have been diagnosed of profound hearing loss (prelin-gual deafness) before the age of three and experienc-ing sensorineural hearexperienc-ing impairment. All cases where the etiology of deafness was unknown were excluded from the study. All of the participants had normal in-telligence as well as showed no signs of any physical disabilities that could impair movement.

The final sample included deaf students of both gen-ders within the calendar age groups of 9.6–10.5 years, 12.6–13.5 years, and 15.6–16.5 years, where 17.7% had inherited deafness, 55.4% were prenatal cases, and 26.9% suffered a hearing impairment after the postnatal pe-riod up to age three. The study design was designed to be semi-longitudinal in nature and divided into three age groups within a 10–18 year old spread. It was con-ducted three times in 2004, 2005, and 2006 (all in the month of October) on the same deaf students within the mentioned three age groups, allowing the same

age groups to be observed (9.6–12.5, 12.6–15.5, and 15.6–18.5 years old) (Tab. 1).

A self-designed questionnaire was used to evaluate the physical activity preferences of the participants. It contained closed-ended questions with multiple-choice answers on how they enjoyed spending their leisure time. The questionnaire was completed with the help of a sign language interpreter who also provided instructions on how to complete the exercise tests measuring aerobic and anaerobic capacity. Each exercise task was preceded by a demonstration with a complete explanation of the instructions and conducted by the same research team each time.

The study was approved by the Bioethics committee of scientific Research at the University school of Physi-cal Education in Katowice, Poland as part of a project funded in part by the state committee for scientific Research. In addition, the legal guardians of the partici-pants were informed of the nature of the experiment and provided their written consent. The participants were informed they may at any time leave the study without providing any reason and reminded that their personal information would remain private in accord-ance with all applicable data privacy laws.

Physiological data was collected by lung vital capac-ity as well as the aerobic and anaerobic capaccapac-ity of the participants was measured. Vital capacity (Vc) was meas-ured in l/min by use of Pony Graphic 3.7 spirometer (cosmed, Italy). Respiratory rates were measured twice as per the manufacturer’s recommendation. Prior to taking a measurement, the participant was asked to breathe calmly for a short period of time and then inhale and exhale as hard as possible, performing a maximum in-halation and maximum exin-halation. After exhaling the remaining residual air volume was measured.

Aerobic capacity was assessed by VO2max ∙ kg–1 and the

PWC170 cycle test on an 828E cycle ergometer (Monark, sweden), which from a technical point of view was the most accommodating for the participants due to their impairment. The task was thoroughly explained to the participants and motivation was provided throughout the test. First, the workload on the cycle ergometer needed to maintain a heart rate of 170 beats per minute was calculated (a higher value in the PWC170 test denotes that more work needs to be performed based on a cor-rectly functioning cardiovascular system). It was deter-mined that two five-minute trails at 30 and 60 W for

Table 1. Participants grouped by age and gender

Year 10 (12) 13 (15) 16 (18) 2004–2006 Girls Boys Girls Boys Girls Boys n

2004 6 16 6 6 12 10 56

2005 6 14 6 6 10 9 51

2006 6 15 6 6 10 10 53

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A. Zwierzchowska, Aerobic and anaerobic capacity and physical activity of the deaf

girls and 50 and 100 W for boys would be adequate. Throughout the test the participants’ heart rate was monitored. PWC170 was calculated by the formula:

170 – f1

f1 – f2

PWC170 = N1 – N2 · , where:

N1 – first test workload,

N2 – second test workload,

f1 – heart rate at the fifth minute of the first test,

f2 – heart rate at the fifth minute of the second test. Maximal oxygen uptake (VO2max) was then estimated based on the Astrand-Ryhming nomogram by taking into consideration steady heart rate at submaximal ef-fort [17]. This provided two variables that could be used to assess aerobic endurance: maximal aerobic power (PWC170 [W/kg]) and and maximal oxygen up-take (VO2max [ml/kg x min]).

Anaerobic capacity was measured by the 30-second Wingate Test, which is a non-invasive method that is suitable for repeated use and considered to be a reliable and accurate measure of anaerobic capacity, as anaerobic processes meet almost 90% of the overall energy demands of the test [18]. The test also registers the power output of a participant as a function of time (throughout the 30 second period of the test) as it increases and then decreases as the effects of fatigue set in. Analysis of power output as a function of time indicates that hu-mans produce maximum power between the first 3–6 seconds of the test, followed by steady decrease until completion. This reveals the nature of the energy con-version process in the working muscles.

The test was performed with the use of a different cycle ergometer (model 829, Monark, sweden) that measures the duration of each pedal revolution. After receiving a visual cue, the participant’s task was to reach a maximum pedaling frequency as fast as possible and maintain this speed for 30 seconds. The load was matched individually to each participant by taking into account their body mass, age, and sex (75g per kg). changes in power output were determined by the duration of each pedal revolution. The test was preceded by a five-minute warm-up on the cycle ergometer with a load suitable to reach a heart rate of 140–150 beat per minute.

Anaerobic capacity and power output were measured with the following variables: maximal anaerobic power – MAP [W], average anaerobic power – AAP [W], time to reach maximal power – TMP [s], time under tension – TUT [s], and the rate of power loss – RPL [%]. Data were recorded and calculated by using McE ver. 2.0 com-puter software.

All statistical analysis was performed with statistica v. 7.1 (statsoft, UsA) and Microsoft Excel software. The mean ( ), median, minimums and maximums, standard deviation (sD), and measures of skewness (sK)

and kurtosis (KU) were calculated for data that were expressed as a ratio variable. Normal distribution was assessed with the shapiro-Wilk test. Univariate ANOVA and correlation analysis using spearman’s rank cor-relation coefficient (rs) was also used. The results were

treated as statistically significant at p < 0.05.

The sexual dimorphism of the participants’ somatic characteristics were determined by the differences of the mean values in each successive year. However, several studies have shown that sexual dimorphism is more accurately measured by indicators that define body pro-portions and not individual morphological characteris-tics. Developmental differences between the studied boys and girls were determined by Mollison’s index of sexual dimorphism (sDI) [19]:

–

sD sDI = ,

where:

sDI – the indicator of sexual dimorphism, – the arithmetic mean of the girls’ characteristics, – the arithmetic mean of the boys’ characteristics, sD – the standard deviation of the boys’

characte-ristics.

Dimorphic differences were treated as significant when the difference between the means ( ) was larger than the standard deviation (sD) of the group of males. The absolute value of the tested variable would indicate the degree of differentiation: the larger the value the larger its value of one standard deviation away from the mean of the boys’ results. A positive value would indicate that this characteristic is in favor of females.

Results

The responses obtained from the questionnaire found that the boys were decidedly less physically active than the girls, with a large majority of them preferring to spend their leisure time passively by watching TV or playing computer games (94.2% and 77.7%, respectively). How-ever, the majority of boys reported that their more ac-tively spent leisure time consisted of bicycling and team sports (80.5%), which was in contrast with the girls who preferred calmer activities such as playing outside and taking walks (51.8%). The results of the questionnaire indicated a lack of statistically significant differences in the leisure activity preferences of the deaf boys and girls. A moderate correlation was found between the boys’ and girls’ preference for passive forms of physical activity (rs= 0.629, p < 0.05) although no significant

relationships were found among active forms of physical activity (Tab. 2, 3).

Physical fitness was analyzed by measuring aerobic and anaerobic capacity. Analysis of the indicators of aerobic capacity and vital capacity (Vc) found a statis-tically significant difference between the boys and girls only in PWC170 [W/kg]. Only the youngest group of girls

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achieved better results than the boys, with the later tests finding that the boys achieved significantly bet-ter results up to the age of 18 (f = 5.6; p < 0.03). Gender had no statistically significant effect on the rate of maximal oxygen uptake, only age was a significant factor differentiating both groups. A decline of VO2max values was noticed in both the boys and girls. A

some-what different picture is seen in the case of Vc, whose values progressively rise over time, although no statis-tically significant differences were found between the boys and girls (Tab. 4).

The sexual dimorphism index found dimorphic vari-ation in favor of the males for PWC170 above the age of 12 and for Vc above the age of 16. It is worth noting that the dimorphism index was highly fluctuated showing no clear trend. Furthermore, the dimorphism index calcu-lated for VO2max pointed to no differences greater than one standard deviation away from the boys’ mean, which indicates that there is no significant variation between genders (Tab. 4).

Analysis of the increases in PWC170 and VO2max finds that gender has no statistically significant effect on these values, with the only statistically significant difference found in the rate of change of vital capacity between 10 and 12 years of age (Fig. 1).

The participants’ ability to perform brief anaerobic effort was based on the following five measured vari-ables: maximal anaerobic power – MAP [W], average anaerobic power – AAP [W], time to reach maximal power – TMP [s], time under tension – TUT [s], and the rate of power loss – RPL [%]. significant differences between the boys and girls were found for MAP and AAP (the oldest group composed of 16-, 17-, and 18-year-olds), RPL (11- and 17-year-olds), and TMP (17-year-olds), all in favor of the boys (Tab. 5). It should be noted that the time needed to reach these values was significantly higher than expected (3–6 seconds).

Anaerobic capacity assessed using the dimorphism index indicates a regular progressive trend for MAP and AAP from the age of 13 onwards, whereas the absolute values point to significant differences between genders in favor of the boys starting from the age of 16. A simi-lar situation, although reversed, was found with RPL, which measures the rate at which fatigue sets in. This variable was found to largely characterize the girl par-ticipants (indicating a smaller tolerance to fatigue).

Table 2. Preferred leisure activities by the deaf girls and boys

Type of activity _nBoys _{= 35} % _nGirls _{= 27} %

Pa ss ive TV 8 22.8 12 44.4 computer 25 71.4 9 33.3 Reading books 1 3.2 2 7.4 social games 2 5.7 4 14.8 A ct ive Bicycling 20 57.7 9 33.3 swimming 3 8.6 3 11.1 Taking walks, playing outdoors 4 7.1 14 51.8 skiing 2 7.4 4 14.8 Team sports 8 22.8 4 11.4 Table 3. spearman’s rank correlation coefficient (rs)

the deaf boys and girls with regard to their preferred leisure activities

Passive leisure activities

Girls Boys Girls x 0.629 Boys 0.629 x Active leisure activities

Girls Boys Girls x 0.143 Boys 0.143 x

Table 4. Aerobic capacity and vital capacity of the deaf girls and boys Age

Vc PWC170 VO2max

± sD ± sD sDI ± sD ± sD sDI ± sD ± sD sDI 10 2.0 ± 0.5 2.5 ± 0.3 –1.5 1.9 ± 0.8 1.7 ± 0.6 0.2 54.2 ± 18.8 50.2 ± 11.3 0.3 11 1.9 ± 0.4 2.3 ± 0.4 –0.8 1.6 ± 0.7 1.8 ± 0.7 –0.2 48.5 ± 18.5 49.1 ± 12.3 –0.1 12 2.14 ± 0.6 2.7 ± 0.8 –0.7 1.8 ± 0.3 2.4 ± 0.7 –0.8 48.2 ± 13.2 50.9 ± 11.3 –0.2 13 2.9 ± 0.2 3.4 ± 0.9 –0.4 1.5 ± 0.3 2.0 ± 0.4 –1.2 40.1 ± 4.0 49.2 ± 10.1 –0.9 14 2.8 ± 0.4 2.9 ± 0.6 –0.2 1.4 ± 0.2 1.7 ± 0.2 –1.6 36.6 ± 4.0 43.2 ± 3.8 –1.6 15 3 ± 0.4 3 ± 0.7 0.1 1.9 ± 0.4 2.3 ± 0.6 –0.7 40.4 ± 5.8 48.4 ± 11.0 –0.7 16 2.9 ± 0.3 3.8 ± 0.5 –1.6 1.7 ± 0.7 2.5 ± 0.7 –1.2 39.7 ± 9.4 44.6 ± 7.6 –0.6 17 2.7 ± 0.5 3.9 ± 0.4 –2.7 1.5 ± 0.6 2.5 ± 1.2 –0.9 39.2 ± 7.7 48.0 ± 13.7 –0.6 18 2.7± 0.6 3.6 ± 0.5 –1.7 1.8 ± 0.6 2.4 ± 0.5 –1.0 41.6 ± 9.3 46.1 ± 7.7 –0.6 * statistically significant difference between genders at p < 0.05; sDI – Mollison’s sexual dimorphism index;

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* statistically significant difference at p < 0.05

– denotes change as a unit of time (year) for VC, PWC170, and VO2max

Figure 1. Rate of change for vital capacity and the indicators measuring the aerobic capacity of the deaf girls (G) and boys (B) among the three age

groups (10–12, 13–15, and 16–18 years old)

Nonetheless, the sDI index was less than one standard deviation away from the boys’ means, which suggests that gender is not a differentiating factor here. The re-maining variables assessing anaerobic capacity oscillated between zero and the absolute value of one standard deviation, indicating no significant differences between the genders (Tab. 5).

Analysis on the rate of change of the variables meas-uring anaerobic capacity found that gender did have a statistically significant effect on increased TMP in the youngest age group. There were no statistically sig-nificant differences in the rate of change for the remain-ing variables between the two genders (Fig. 2).

Ta bl e 5 . A na er ob ic c ap ac it y o f t he d ea f g ir ls a nd b oy s A ge M A P [ W /kg ] A A P [ W /kg ] T M P [ s] TUT [s ] R PL [ % ] ± sD ± sD sDI ± sD ± sD sDI ± sD ± sD sDI ± sD ± sD sDI ± sD ± sD sDI 10 5.1 ± 1.7 6.9 ± 2.0 –0.8 3.6 ± 1.7 5.4 ± 1.6 –1.0 15.2 ± 5.4 11.6 ± 4.4 0.8 1.6 ± 1.0 1.1 ± 1.3 0.4 17 ± 4.8 16.8 ± 7.8 0.1 11 5.5 ± 2.3 6.3 ± 1.5 –0.5 4.1 ± 1.9 4.9 ± 1.4 –0.5 12.7 ± 5.5 16.1 ± 7.8 –0.4 3.08 ± 2.2 2.1 ± 2.6 0.3 24.7 ± 7.4 14.3 ± 8.1 1.2 12 5.7 ± 2.2 7.6 ± 2.1 –0.8 4.4 ± 1.9 5.9 ± 1.7 –0.9 9.9 ± 5.2 11.5 ± 4.5 –0.3 3.3 ± 2.7 1.9 ± 0.8 1.6 28.7 ± 17.1 17.6 ± 5.8 1.9 13 7.7 ± 1.2 7.5 ± 1.1 0.1 5.7 ± 0.5 6.1 ± 0.9 –0.5 12.5 ± 3.3 10.8 ± 2.8 0.6 1.6 ± 0.7 1.0 ± 1.7 –0.2 21.7 ± 9.7 14.2 ± 3.8 1.9 14 6.7 ± 1.0 8.0 ± 1.3 –0.9 5.2 ± 0.4 6.5 ± 0.9 –1.4 13.5 ± 2.5 12.0 ± 5 0.6 2.7 ± 1.2 4.7 ± 4.6 –0.4 16.9 ± 9.5 12.6 ± 5.8 0.7 15 7.4 ± 0.4 8.7 ± 1.0 –1.2 5.5 ± 0.5 7.2 ± 0.9 –1.7 12.5 ± 2.6 10.4 ± 2.8 0.7 3.6 ± 2.2 3.5 ± 2.3 0.03 22.5 ± 12.5 15.3 ± 2.6 2.7 16 6.9 ± 2.2 9.5 ± 1.2 –1.9 5.09 ± 1.7 7.5 ± 0.7 –3.1 10.2 ± 3.0 12.8 ± 5.8 –0.4 1.3 ± 1.2 1.2 ± 2.5 –0.01 25.6 ± 17.7 15.7 ± 7.1 1.4 17 7.3 ± 1.7 9.4 ± 1.8 –1.2 5.5 ± 1.1 7.4 ± 1.4 –1.4 10.2 ± 3.4 16.2 ± 6.6 –0.9 2.5 ± 1.5 2.0 ± 1.6 0.23 22.3 ± 7.9 11.1 ± 7.8 1.4 18 6.8 ± 1.4 9.5 ± 1.2 –2.2 5.2 ± 0.9 7.8 ± 0.7 –3.3 10.2 ± 1.4 11.7 ± 4.0 0.3 2.6 ± 1.3 3.4 ± 2.8 –0.3 20.4 ± 7.2 13.6 ± 6.7 1.0 * s ta ti st ic al ly s ig ni fi ca nt d if fe re nc e b et w ee n g en de rs a t p < 0 .0 5; sD I – M ol lis on ’s s ex ua l d im or ph is m i nd ex ; sh ad ed va lu es i nd ic ate a d if fe re nc e i n d im or ph ic t ra it s ( sD I > sD )

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Discussion

Lung vital capacity has been medically verified to increase together with maturity, although it remains highly variable not only due to age but also gender [21]. This study confirmed the progressive rise of vital capacity in both females and males, with significant gender dif-ferences emerging after the age of 15. However, no sig-nificant sexual dimorphic differences in the rate of change of this physiological variable were found to occur in this group of deaf 10–18 year-olds.

The progressive variability of various somatic charac-teristics defining human development have been found to determine individual exercise capacity. This was the most visible in the oldest group of deaf participants (16-, 17-, and 18-years-old), where gender was a factor differentiating their aerobic and anaerobic capacity with males showing a considerable advantage over their fe-male peers. These findings correspond with the results of able-bodied young adults, due in part that the physio-logical adaption of children’s bodies to exercise signifi-cantly differs than in mature adults. These differences

are particularly noticeable in exercise performed at maximal and supramaximal intensities that use pre-dominantly anaerobic energy processes. This is due to children having a less developed ability to resynthe-size high-energy resources based on anaerobic energy processes as well as a reduced ability to neutralize the byproducts of anaerobic exercise. Hence, children ob-tain lower measures of maximal anaerobic power and feature less tolerance to homeostatic imbalance during physical effort [22, 23]. A study by Bar-Or [18] has also shown that children’s lower levels of anaerobic capacity may be caused by reduced capacity to use muscle gly-cogen during physical effort. This was evidenced by a slower rate of anaerobic glycolysis and lower blood lactate concentration levels in the working muscles when compared to adults. This relationship was verified in the present study of deaf children and youth, where the potential for effort increased with age and which was most visible among the group of deaf males. In terms of the differentiation between boys’ and girls’ anaerobic capacity, cempla and Bawelski [24] were more critical of the opinion that boys featured a greater increase in

* statistically significant difference at p < 0.05

– denotes change as a unit of time (year) for maximal anaerobic power (MAP) AAP – average anaerobic power

TMP – time to reach maximal power TUT – time under tension RPL – the rate of power loss

Figure 2. The rate of change of variables measuring anaerobic capacity for the deaf girls (G) and boys (B)

among the three age groups (10–12, 13–15, and 16–18 years old)

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maximal anaerobic power (MAP) relative to girls, al-though the results obtained in this study do not con-firm their assessment.

Research on the physical activity of disabled children and youth has indicated that the hearing impaired do not see themselves as individuals who are dysfunc-tional when compared to the rest of the population. This group has been found to have very high self-esteem in regards to their habits and ability to perform physical exercise, while at the same time reporting that they do not feel to have physical ability levels lower than their hearing peers [25]. Among a group of disabled indivi-duals, the hearing impaired presented a high level of phy-sical fitness [26]. Nonetheless, these observations have been contradicted by a number of empirical studies on the aerobic and anaerobic capacity of the deaf in com-parison with the non-disabled [11, 27, 28]. However, few have concentrated on the gender-based differences of the deaf’s aerobic and anaerobic capacity.

shepard, Ward, and Lee [28] examined 15 boys and 14 girls (ages 12 to 15) finding that only 40% were found to meet the norms for their age and sex. These authors pointed out that age and gender did differentiate the results, which followed a progressive trend together with age, although these changes were statistically insignifi-cant for the group of girls. They also drew attention to the increased adiposity of the deaf, especially in the case of females, which may have contributed to this finding. Other researchers have stated that deaf children and adolescents feature lower tolerance to effort during aerobic and anaerobic testing [11, 27]. The results of this study support this hypothesis especially in the case of females. The variable measuring power loss (RPL) was signifi-cantly lower among boys in the oldest age group, which reflects their higher (better) tolerance during short-term anaerobic exercise (Tab. 5). Here, the sexual dimorphism index had a positive value as the girls’ recovery process required more time, but was at the same time less than one standard deviation from the boys’ mean, finding that RPL was not a characteristic that differentiates gender.

Of considerable interest is also one of the other ana-lyzed variables, the time to reach maximal anaerobic power (TMP). The time to reach maximal power has been defined to occur at around 3–6 seconds. A surpris-ing outcome in this study was that both the boys and girls had difficulty in reaching their maximum heart rate within this time frame. One of the only explana-tions for this result may be that this group was less motivated (volition). Motivation is an important fac-tor not only for succeeding in sports but also, above all, guides individuals to engage in suitable fitness training. The concept of motivation has been defined as a “hy-pothetical construct” [29], as a state of readiness to take specific action stemming from both individual needs and external factors and which possesses a certain sig-nificance that cannot be completely defined through empirical evidence. Evidence of this fundamental prob-lem can be found in the responses provided by the

par-ticipants in the questionnaire on their physical activity preferences, which indicated that individual forms of physical activity were highly preferred. Yet, it is common knowledge that nothing better motivates individuals than interpersonal relationships and healthy competi-tion. It should be taken into account that deafness is a mitigating factor in social behavior (feelings of strong alienation from both able-bodied and disabled individuals) and might have been reflected in the participants’ res-ponses. For example, their preference for these forms of physical activity are consistent with those found in a group of deaf students in Karachi, Pakistan [30]. It is worth noting that the deaf students from Karachi also ranked individual sports and forms of recreation first, while rating “improving health and the body” the least motivating factor for their participation in physical ac-tivity. Therefore, it is difficult to expect that deaf indi-viduals would present large differences in their prefe-rences for various forms of physical activity as is the case for the able-bodied. The findings of this study – showing a moderate correlation between girls and boys who prefer passive forms of leisure activities – allow us to assume that deafness acts to limit both the prefe-rences and motivation for physical activity and is an issue that requires further investigation.

Conclusions

The ability to perform increasing amounts of aerobic and anaerobic work was found to increase together with age for both the deaf male and female participants. Gender-based differences were noted for aerobic (from the age of 12) and anaerobic capacity (from the age of 14). In contrast, no statistically significant differences were observed in the rate of developmental change that de-fines aerobic and anaerobic capacity.

The study found no differences in the physical activity preferences of the deaf boys and girls, which is believed to show that deafness is a factor that limits and, con-sequently, unifies what forms of physical activity the deaf prefer to engage in. It is believed that the social environ-ment plays a large role in stimulating the behavior of deaf children and adolescents.

It was found that deaf boys perform aerobic and anaerobic effort increasingly better as they get older when compared with their female peers. Based on this study’s findings (TMP) and observations made during the tests, it is believed that motivation significantly affected the attained results, possibly due to communication and in-terpersonal difficulties. This signifies the need for pro-viding additional external motivation for the hearing impaired when measuring exercise capacity and during physical education classes, making this a challenge to be met by both teachers and researchers. such a conclusion was also reached by Jonsson and Gustafsson [31], who reported that motivation is an important criterion when measuring the respiratory efficiency of the hearing impaired.

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Paper received by the Editor: December 10, 2012 Paper accepted for publication: April 26, 2013

Correspondence address

Anna Zwierzchowska

Zakład Korektywy i WF specjalnego Akademia Wychowania Fizycznego im. Jerzego Kukuczki

ul Mikołowska 72a 40-066 Katowice, Poland