Abstract The drop jump is a frequently used and widely examined training exercise aimed at the development of one of the most important qualities in sports with speed-strength character – the explosive power. The common options for execution of this exercise suppose the general development of the explosive power of the lower limbs without taking into consideration the kinematics and dynamics related to a certain kind of sport or sports discipline. The main aim of the research is to reveal reliable interdependencies of kinematic and dynamic parameters of movements between the drop jump on an inclined platform and the take-off from the board in the long jump and the triple jump. The research is aimed at modeling the parameters of execution of this exercise so that it can meet the kinematics and dynamics of the take-off in the horizontal athletics jumps. We examined some kinematic and dynamic parameters of movements in the drop jump on an inclined platform with different angle of inclination and made a comparison with the same parameters in the take-off in the competitive events long jump and triple jump. We determined significant differences and conformities between the researched parameters. On the base of the conclusions made we designed a piece of training equipment so that this exercise can be implemented in practice.

ABSTRACT The aim of this study is to investigate the changes in the sports achievements for 5,000 meters running as a result of interval normobaric hypoxia training. Ten college sportsmen preparing for national and students long distance track and field championships, were randomly assigned into two groups - Experimental and Control. The Experimental group performed 3 training sessions weekly with interval normobaric hypoxia. The experiment was of 6 weeks duration. Every new week the hypoxic stimulus was increased with 500 m simulated altitude while speed of running remained constant during the whole experiment. The training speed of running was determined individually as 70% from the maximal running speed at VO2 max from incremental cardio-pulmonary test to exhaustion. The control group was performing standard training at 560 m altitude. The results show statistically significant improvement (p< 0.05) in the sports results in the experimental group which improved their personal best records in 5000 m long distance. The results also show small, but significant increase in VO2 max for the Experimental group, while there is not such a tendency in the Control group.

ABSTRACT The aim of this study was to seek a possible significant correlation between post-competition blood lactate concentrations (BLc) and the times achieved in swimming events. The research was done among 71 swimmers (44 men and 27 women) of the Bulgarian national swimming team. The average age of the participants was 17.48 ± 2.50 years (18.02 ± 2.62 for men and 16.59 ± 2.00 for women). Blood lactate concentrations were measured 3 to 6 min after the finals of all individual swimming events in official competitions and the time ranged between 653 and 898 FINA points. The total number of measurements was 280 (175 samples from men and 105 from women) collected during a 3-year period (2016 -2018). The results indicated that the highest mean values of BLc were obtained after sprint distances: men’s 100 m freestyle (16.91 ± 4.32 mmol/L) and women’s 100 m butterfly (16.89 ± 2.35 mmol/L). The lowest mean values were measured after distance swimming of 1500 m freestyle: 7.14 ± 3.34 mmol/L for the man and 5.10 mmol/L for the women. Statistically significant coefficients of correlation between swimming times and BLc were observed in men’s swimming events of 100 m butterfly (r = -0.484); 100 m backstroke (r = -0.721); 100 m freestyle (r = -0.854); 50 m freestyle (r = -0.891) and women’s swimming event of 50 m freestyle (r = -0.688). In conclusion, there is no statistically significant difference in the post-competitive BLc levels depending on gender; significant differences in mean values of BLc between breaststroke and all other strokes; in sprint swimming events (especially in 100 m freestyle) statistically significant correlations between BLc and swimming times were observed.

ABSTRACT In this study, we:(a) developed allometric exponents for scaling Wingate anaerobic test (WAnT) power data that are effective in controlling body mass(BM) influence; and (b) established a normative WAnT data set for young soccer players. Forty-six players completed a standard WAnT. Allometric exponents and percentile ranking for peak power (PP), average power (AP) and power output for 30 s (W 30 s) were established. Allometric exponents “b” for PP, AP and W (30 s) scaled for BM were 0.72,0.78 and 0.85 respectively using braking force 75 g.kg-1, markedly higher from the theoretical suggested of b=0.67. The study shows the possibilities of applying the allometric scaling in the coaches practice. If these exponents in allometric scaling of young soccer players are used, WAnT power values will provide coaches with valid means for comparing power production between individuals without the confounding influence of BM.

ASTRACT Focus of this research is the relationship between the motor abilities. The interest in this topic is dictated from the fact that there isn’t enough information about it in elite female football. For the purpose of the research we made tests to define the level of development of the motor abilities of 68 elite female football players. We also made a descriptive statistics and correlation analysis and we received the following results: descriptive statistics shows that the researched indicators are highly homogeneous (in range of V% =2,67 to 5,05); the correlation between accelerative abilities and maximal sprinting abilities is moderate and positive (r= 0,634); the correlation between power abilities with explosive character and other researched abilities is moderate and negative (r= -0,430, r= -0,494, r= -0,455); the speed endurance abilities have moderate to strong and positive correlation with the accelerative and maximal sprinting abilities (r= 0,600, r= 0,809). Conclusions: 1) Improving the power abilities with explosive character creates beneficial conditions in development of the other motor abilities; 2) Improving of the speed abilities is a major component of the conditioning in female soccer; 3) The most important factor for improving the speed endurance is creating a “speed reserve”.

ABSTRACT An estimate of body mass index (BMI) is a convenient technique to determine a healthy weight in accordance with height and is based on certain anthropometric parameters. This study was undertaken to statistically analyze the differential significance of anthropometric parameters in contributing to regional and age variation in BMI in a cohort population. The study population comprised of 101 school teachers from Mumbai (coastal) and Gwalior (plains) regions of both sex (males=76) and (females=25). The data on age, waist circumference and hip circumference was obtained and subjected to regression analysis using the IBM SPSS version 22 software. In general, the results show that, waist in males and hip circumference in females is the single most important parameter in estimating the BMI. However, by considering all the three parameters i.e. age, waist and hip circumferences, the accuracy of BMI estimation can be enhanced both in males and females. The results exhibit a significant effect of regional influence but marginal influence of age in estimating the BMI. A definite and interesting difference in the contribution of anthropometric parameters in the regional variation of BMI was detected. The observations strongly suggest development of region-wise as well as age-wise BMI estimation models.

ABSTRACT Rhythmical abilities, being part of the coordination abilities of athletes, are an important factor for the successful realization in the complex-coordination kinds of sports. The initial learning of the exercises requires the strict following of a rhythm, set with music, to distinguish the different phases of motor activities and their duration. The rhythm of motor activities is subjected to the inner rhythm of the performer, to the different rhythm of the movements with the apparatuses, and to the rhythmical structure of the music accompaniment. The rhythmical execution and the harmonious connection between movements and music is one of the major characteristics of gymnastics events. The aim of the research is to study the rhythmical abilities of athletes, practicing kinds of sports whose motor activity requires the use of musical accompaniment and those which do not require such. The research was done among 72 individuals. Methods: For coordination in rhythm we used four tests: Frontalkickingwithlegsandarmsonthewall - (Fkla), Jumpsinfoursquares – (J4sq), Crossover jumps in four squares – (Cj4sq), Kicking with legs and arms – (Kla). The results from the tests – Jumps in four squares ? Crossover jumps in four squares – correlate with each other significantly with the gymnasts (.710**) and moderately with the athletes practicing other kinds of sports (.358**). The results from the agility tests correlate significantly with the gymnasts (.723**), and moderately with the athletes from the other sports (.654**). The mean values (?=10.20, ?=4.41) and (?=10.6, ?=8.24) of the tests, performed with arms and legs are better with the gymnasts. The results from the research showed the necessity of adapting the applied tests so that they could be implemented in research with different age groups.

ABSTRACT The activities performed by people who go on military missions or on Antarctic expeditions to Livingston Island often arise various questions and interpretations. On the one hand, they suppose a tendency toward risky acts; on the other hand, they require discipline and balance in one’s behavior. The aim of our study was to examine the peculiarities of the need of security and the need of sensation seeking as basic personal variables of participants in military missions in Afghanistan and Bulgarian Antarctic expeditions and to examine their relation to the coping strategies applied. The research was done among 141 individuals (107 participants in Bulgarian military contingent which took part in an international NATO mission in Afghanistan in 2017 and 34 participants in two Bulgarian Antarctic expedition on Livingston Island in 2014/2015 and 2016/2017. All the individuals researched were divided into groups according to their age, gender and rank. We used: 1) Need of security assessment test (A. Velichkov, M. Radoslavova, S. Vassileva, V. Todorov, 1998). 2) Coping Orientations to Problems Experienced Scale – COPE – 1 (Carver, et al, 1989), adapted for Bulgarian conditions (M. Georgiev et al, 2003) and 3) Research methods of psychic instability and sensation seeking, adapted by A. Velichkov and M. Radoslavova (2005). It is based on M. Zuckerman’s methods (1979, 1994). The researched participants in military missions and the explorers from Antarctic expeditions showed significant differences along the indexes between the two groups. The participants in military mission have lower values along all scales of the need of sensation seeking in comparison with the established norms for the Bulgarian sample and higher values of the need of security. The results of the participants in the Antarctic expeditions are particularly interesting. Regardless of their pronounced inclination to adventurous experiences and risky behavior, to hasty and impulsive actions, when subjected to tension, uncertainty and stress they revert to cognitive engaged coping strategies, which suppose active coping, planning, mobilization and a sense of control over the situation. The established regularities are a valuable reference point both for the selection of the participants in military missions and expeditions and for the insurance of their safety.

ABSTRACT Diabetes is a worldwide health problem and is prevalent in both developed and developing countries. Type 2 diabetes is characterized as being insulin resistant with inadequate insulin response to maintain a normal concentration of glucose in the blood. It is estimated that Type 2 diabetes accounts for 90–95% of all diabetes. Type 2 diabetes can be described as a chronic and progressive disease, caused by a combination of resistance to insulin action and impaired insulin secretion, where obesity and overweight, due to excess body fat with fat distributed in the upper body are the main complications of insulin resistance. With the dramatic increase in obesity, low-carbohydrate, high-protein, high-fat diets have become increasingly popular. Diets limiting the amount of carbohydrate intake have been called low-carbohydrate or very-low-carbohydrate, high-protein, high-fat, Banting and ketogenic diets, and are characterized by 50g or less carbohydrates per day. High fat low carbohydrate diets have been found to be different from the traditional diets of most cultures. Recent studies however show that there are potential benefits associated with reducing carbohydrates and increasing fat intake. Low-carbohydrate diets have become very popular for weight loss. Although they may improve some metabolic markers, particularly in Type 2 diabetes mellitus, they seemingly have an effect on body weight, glycemic control and cardiovascular risk factors as well. Research shows that by reducing aerobic exercise capacity; poor glycemic control, increase in cardiovascular risk and elevated glycosylated hemoglobin (HbA1c) are common with Type 2 diabetics. Aerobic exercise capacity and glycemic control in Type 2 diabetes can be improved by being physically active. Regular physical activity along with diet therapy provides health benefits and has been found to be essential for primary and secondary prevention of most metabolic disorders.