Албена Димитрова | Bulgarian Academy of Sciences (original) (raw)

Papers by Албена Димитрова

Series on Biomechanics, Nov 27, 2023

Body weight, Body height, Body mass High-performance sport demands the development of a variety o... more Body weight, Body height, Body mass High-performance sport demands the development of a variety of morphological and motor abilities. Childhood and adolescence are the main periods for the progress of these skills and the selection of highly qualified athletes. This study aims to identify and compare the body composition profile of growing female athletes to support their sports preparation and selection. The sample includes 72 (27 rhythmic gymnasts /RG/ and 45 tennis players /TP/) adolescent female athletes, divided into two experimental groups according to their age. Body height for each subject is measured using standard anthropometric tools and techniques. The body composition profile was determined by multi-frequency bioelectrical impedance measurements (InBody 170 analyzer). Statistical analysis is made by SPSS 16.00. The independent samples t-test (p≤0.05) is applied to assess the differences in anthropometric variables between TP and RG. The differences in body composition components between RG and TP are well expressed in both age groups. Through all assessed age periods TP are higher and heavier than the RG at the same age. Analysis of the segmental distribution of body composition components showed that TP has significantly higher lean body mass and fat mass values than RG, excluding fat mass (%) on the upper extremities.

Series on Biomechanics, Aug 1, 2023

Sport has a profound impact on the development of teenagers, contributing to their physical healt... more Sport has a profound impact on the development of teenagers, contributing to their physical health, psychological well-being, character building, and social interactions. In the current article, we report results from the anthropometric measurement of 43 boys tennis players (BTP) and 55 non-players (BN) 14-17 years old. We determine the average mass and height of each group and generate a mathematical 3D model of the so-defined average tennis player (ATP) and nonplayer (ANP). Within the model, every segment of the body is represented via a 3D geometrical body. Using the analytical properties of these bodies we determine the mass of each segment, its center of mass and the principal moments of inertia. We compare the results of both groups trying to elucidate the influence of the sport on the physical development the teenage players 14-17 years old. We hope our study will encourage teenagers to participate in sports activities, whether competitively or recreationally.

In this article, we present the findings from the anthropometric measurement of 55 non-players (G... more In this article, we present the findings from the anthropometric measurement of 55 non-players (GN) and 33 girls tennis players (GTP) ages 14 to 17. In order to create a mathematical 3D model of the average girl player (AGP) and nonplayer (AGNP), we determine each group's average mass and height. Every segment of the body is represented by a geometrical body in the model. Based on the model, we calculate each segment's mass-inertial characteristics, such as its volume, mass, centres of mass, and moments of inertia, using the analytical properties of these 3D geometric bodies. We make an effort to understand how the sport affects the physical development of teenage girl players, ages 14 to 17, by contrasting the results of the two groups. Our study is intended to inspire teenage girls to engage in sports, whether for fun or competition.

Folia Medica, Apr 30, 2022

Introduction: The intensity of tennis training together with specific exercises may be reflected ... more Introduction: The intensity of tennis training together with specific exercises may be reflected in the morphological profile of tennis players. Aim: To evaluate the impact of sports training on the body composition of female tennis players in the 11-13-year competition category. Materials and methods: The study included an experimental group of 27 female tennis players (mean age 12.43±0.91 years) and 115 schoolgirls (mean age 12.55±0.88 years) as a control group. The following features were investigated: body height, body weight, body mass index, waist-to-hip ratio, muscle mass, fat mass, fat-free mass, percentage of body fat, total body water. The visceral adipose tissue and subcutaneous adipose tissue were computed using the Brambilla's equation. Results: In comparison with the control group, tennis players have higher values of muscle mass (p<0.04), total body water (p<0.05), fat-free mass (p<0.04) and lower values of body fat percentage (p<0.04). The rest of the parameters were not found to have statistically significant differences. Conclusions: We conclude that sports training influences some morphological parameters of female tennis players.

Tennis is a sport characterized by high physical activity and frequently repeated motions, especi... more Tennis is a sport characterized by high physical activity and frequently repeated motions, especially for the dominant upper limb. This creates differences between upper limbs and lead to an asymmetric distribution of muscle mass and unbalanced muscle tonus. The aim of the study is to estimate the degree of muscle mass asymmetry between the dominant and non-dominant limbs in young Bulgarian tennis players, using multi-frequency bioelectrical impedance measurements. The study sample includes 14 male tennis players and 11 school children aged 12 years. Segmental analysis of body composition was done by bioelectrical impedance analyzer (model: InBody 170). The athletes have a larger muscle mass of the dominant upper limb compared to the non-dominant. The non-athlete boys are characterized with lower asymmetry coefficient level of the upper limbs' muscle mass compared to the tennis players (p < 0.05). The significant relationship between asymmetry coefficients of the upper limbs,...

Effect of Sports Training on Morphological Characteristics of Bulgarian Female Tennis Players, 2022

The aim of the present study is to investigate a grip strength in young male tennis players aged ... more The aim of the present study is to investigate a grip strength in young male tennis players aged 9-11 years. A total of 39 children (15 tennis players and 24 pupils) took part in the study. All participants were assessed for height, weight and BMI. The grip strength was measured by hand dynamometer in kilograms-force at both (dominant and non-dominant) upper limbs. Statistical analysis was made by SPSS 16.00 for Windows. The measuring showed that sportsmen have higher values on right upper limb hand grip strength than the control group (11.8 kg and 8.00 kg). There are similar results on the left upper limb: 7.79 kg (athletes) and 6.92 kg (non-athletes). A considerably higher difference of hand grip strength between the right and left hand was discovered in athletes (3.67kg.), compared to the control group (0.87 kg). The correlation is significantly higher between the left hand grip strength and body mass index (p < 0.01), weight and hand grip strength on the left hand (p < 0.0...

Anthropometric characteristic of the chest of children gives information about the changes that o... more Anthropometric characteristic of the chest of children gives information about the changes that occur in its size and shape during periods of growth and development. The aim of the present study is to characterize the main anthropometric dimensions of the chest in healthy adolescent children in terms of gender and age. During the period 2016-2018 a cross-sectional study was carried out in five secondary schools in Sofia, Bulgaria. A total of 445 schoolchildren (234 boys and 221 girls) aged 8-17 were studied. The participants in the study are divided into three age groups: 8-10 years, 11-13 years and 14-17 years. The main anthropometric dimensions of the thorax were assessed: chest breadth, chest depth and chest circumference at respiratory pause. Based on the data for both diameters, the thoracic index is calculated. The chest of the boys increased in width by 5.51 cm, and in the anterior-posterior direction by 3.98 cm. In girls the increase of the chest in width is less - 3.80 cm, and the reported absolute increase in the anterior-posterior dimensions is 2.29 cm. In adolescent boys the values of the thoracic index are between 67.61% and 68.62%, which determines the conical shape of their chest, and in girls between 66.77% and 65.62%, which determines a relatively flatter shape. The differences between the two genders are statistically significant only in the group of 14-17-year olds (p≤0.001). The chest circumference of boys is larger than that of girls and increases significantly between the three age periods. These results show that throughout the study period (8-17 years) the boys have higher values of all chest dimensions than girls. The most pronounced statistically significant gender differences are observed in the age group 14-17 years (p≤0.05). The thoracic index data show that 8-17-year old boys have a relatively deeper and girls have a relatively wider chest. During childhood and adolescence chest diameters and chest circumference increase, highlighted in 8-13 years old girls and 14-17 years old boys.

The main goal of each athlete is to achieve optimal performance. There are varieties of factors t... more The main goal of each athlete is to achieve optimal performance. There are varieties of factors that have been indicated to have a positive impact on sports ,u"."rr. Thi aim ofthe present study is to show the factor structure of anthropometric chaiacteristics in adolescent tennis players. An exploratory factor analysis was conducted (Varimax method) on 42 anthropometric variables measured on isz male and 148 female tennis athletes, aged 8-17 years. All tennis players (Tp) included in the study have been training tennis for 2years, not less than 3 times weekly, and voluntarily participate in the present study. Statistical analysis of the collected data was performed by software SPSS 16.00. The factor structure of the anthroptmetric characterlstic in 8-17 years old tennis players showed similar results in both sexes in terms of the total explained variance (7g.og1% in boys arrd19.884oh in girls)' The two-factor and five-factor orthogonal structures were found to describe male and female groups, respectively' The conducted factor analysis of the anthropometric characteristic in adolescent tennis players allows optimizing the system for sports selection and training. The morphological parameters with the highest weight of the factor are most strongly influenced by sports activitY.

Body composition is a major factor determining achievements in racket sports (tennis, table tenni... more Body composition is a major factor determining achievements in racket sports (tennis, table tennis and squash) and plays a significant role in the level of physical development. The aim of the present study is to assess body composition in young Bulgarian tennis players. A total of 86 boys (26 tennis players, 60 schoolchildren), aged 10-11 years, participated in this cross-sectional study. Body composition was determined by means of multi-frequency bioelectrical impedance measurements (BIA). The following anthropometric indices were calculated: fat mass index (FMI=fat mass/ stature 2 , kg/ m 2), fat free mass index (FFMI= fat free mass/ stature 2 , kg/m 2). Comparisons between groups were performed by Student t-test (P< 0.05). Relationships between anthropometric features and training experience of tennis players were assessed by Pearson's correlation. Tennis players (TP) had significantly lower weight, body mass index, body fat and percent body fat compared to non-tennis players (NTP). The mean values of FMI in TP were 3.08 ± 1.42 kg/ m 2 and they were lower than these in untrained controls (4.99 ± 2.99 kg/m 2). The average values of FFMI in the investigated groups were equal (P>0.05). In athlete they were 14.12± 0.98 kg/m 2 and in non-athlete-14.30 ± 1.04 kg/ m 2. Training experience of TP was significantly and negatively correlated with several anthropometric traits and indices of body composition. Physical activity , particular tennis training was inversely correlated with body weight, body fat and FMI, moderately correlated with FFM in children.

Objectives. This study aimed to characterize the sexual differences in chest dimensions and shape... more Objectives. This study aimed to characterize the sexual differences in chest dimensions and shape in Bulgarian schoolchildren and the relation of chest measurements with vital capacity and some anthropometric parameters. Material and methods. A total of 107 (60 boys and 47 girls) schoolchildren aged 9-10 years from Sofia, Bulgaria were studied. Chest's diameters and circumference, waist circumference and vital capacity of each subject were measured. Thoracic index and BMI were calculated. Results. In 9-10 years old children the sexual differences of some variables are well expressed as the boys had greater values than girls. Conclusions. Significant positive association of all chest dimensions with anthropometric features in both sexes was observed. A significant and positive relation between some torso parameters and vital capacity also was found. In boys it was low and in girls-moderate.

The aim is to determine the influence of sport activity on the body composition compartments in y... more The aim is to determine the influence of sport activity on the body composition compartments in young rhythmic gymnasts at different age categories. A total of 27 rhythmic gymnasts, who had trained at least for two years and not less than 20 hours weekly, were tested. Athletes were divided into two groups: pre junior (mean age 8.87 ± 0.72 years) and junior (mean age 11.55 ± 0.52 years). The bioelectrical impedance analysis was used to evaluate the body composition. The gymnasts in pre junior` group had significantly lower mean values of height, weight, muscle mass, total body water and fat free mass compared to junior group. A significant positive correlation with strong intensity between muscle mass and height, weight, total body water and fat free mass in both assessed groups was established. The muscle mass of the gymnasts rises with increasing the sport experience but the body fat percentage and other obesity parameters keep relatively constant mean values.

Series on Biomechanics, Nov 27, 2023

Series on Biomechanics, Aug 1, 2023

Folia Medica, Apr 30, 2022

Effect of Sports Training on Morphological Characteristics of Bulgarian Female Tennis Players, 2022