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Temelkova-Kurktschiev T.,National Sports Academy | Temelkova-Kurktschiev T.,Robert Koch German Medical Center | Stefanov T.,National Sports Academy
Experimental and Clinical Endocrinology and Diabetes | Year: 2012

Obesity and type 2 diabetes mellitus are multifactorial health threats caused by a complex interplay between genetic predisposition and the environment with dramatically increasing worldwide prevalence. The role of heritability in their etiology is well recognized, however, the numerous attempts made in order certain genetic variants determining individual susceptibility to be identified have had limited success, until recently. At present the advancements in human genetics and the utilization of the genome-wide association approach have led to the identification of over 20 genetic loci associated with, respectively obesity and type 2 diabetes. Most of the genes identified to date, however, have modest effect on disease risk suggesting that both diseases are unlikely to develop without the individual being exposed to obesity- and/or type 2 diabetes-promoting environment. Indeed, unhealthy lifestyle, characterized by physical inactivity and food overconsumption is an unequivocally established risk factor for obesity and type 2 diabetes. Numerous epidemiological studies and randomized controlled trials, on the other hand, have demonstrated that lifestyle modification is effective in obesity and type 2 diabetes prevention. Furthermore, gene-lifestyle interaction studies suggest that genetic susceptibility to obesity and type 2 diabetes may be partially or totally kept under control by healthy lifestyle or lifestyle modification and that lifestyle determines whether an individual is likely to develop the disease. Inherited factors, however, seem to influence individual response to a lifestyle intervention program and even the motivation for lifestyle change. Personalized interventions according to genotype may be, therefore, considered in the future. By then lifestyle modification targeting dietary change and increased physical activity may be recommended for successful obesity and type 2 diabetes prevention irrespectively of genetic susceptibility. © Georg Thieme Verlag KG Stuttgart - New York.

Michailov M.L.,National Sports Academy | Morrison A.,Bern Medical | Ketenliev M.M.,Directorate of Control and Management of Sports Preparation | Pentcheva B.P.,Directorate of Control and Management of Sports Preparation
International Journal of Sports Physiology and Performance | Year: 2015

Traditional treadmill or bicycle ergometry neglects the upper-body musculature that predominantly limits or terminates rock-climbing performance (ie, the inability to continually pull up one's body mass or "hang on"). Purpose: To develop an incremental maximal upper-body ergometer test (UBT) to evaluate climbers' aerobic fitness and sport-specific work capacity and to compare these results with a traditional treadmill protocol. Methods: Eleven elite sport climbers (best redpoint grade Fr.8b) performed a UBT on a vertically mounted rowing ergometer and, on a separate occasion, performed a maximal incremental treadmill test (TMT). Cardiorespiratory parameters were measured continuously. Lactate (La) samples were collected. Results: Peak oxygen consumption (VO2peak) and heart rate in UBT and TMT were 34.1 ± 4.1 vs 58.3 ± 2.6 mL · min-1 · kg-1 and 185 ± 8 vs 197 ± 8 beats/min, respectively, and both variables were of significantly lower magnitude during UBT (P < .001). End-of-test La levels for UBT (11.9 ± 1.7 mmol/L) and TMT (12.3 ± 2.5 mmol/L) were similar (P = .554). Treadmill VO2peak was not correlated with either upper-body (UB) VO2peak (P = .854) or redpoint and on-sight climbing grade ability (P > .05). UB VO2peak and peak power output per kg body mass were both strongly correlated (P < .05) with climbing grade ability. The highest correlation coefficient was calculated between current on-sight grade and UB VO2peak (r = .85, P = .001). Conclusion: UBT aerobic- and work-capacity results were strongly correlated to climbing-performance variables and reflected sport-specific fatigue, and TMT results were not. UBT is preferred to TMT to test and monitor dedicated and elite rock climbers' training status. © 2015 Human Kinetics, Inc.

Bell D.R.,University of Wisconsin - Madison | Guskiewicz K.M.,University of North Carolina at Chapel Hill | Clark M.A.,National Sports Academy | Padua D.A.,University of North Carolina at Chapel Hill
Sports Health | Year: 2011

Context: The Balance Error Scoring System (BESS) is commonly used by researchers and clinicians to evaluate balance. A growing number of studies are using the BESS as an outcome measure beyond the scope of its original purpose. Objective: To provide an objective systematic review of the reliability and validity of the BESS. Data Sources: PubMed and CINHAL were searched using Balance Error Scoring System from January 1999 through December 2010. Study Selection: Selection was based on establishment of the reliability and validity of the BESS. Research articles were selected if they established reliability or validity (criterion related or construct) of the BESS, were written in English, and used the BESS as an outcome measure. Abstracts were not considered. Results: Reliability of the total BESS score and individual stances ranged from poor to moderate to good, depending on the type of reliability assessed. The BESS has criterion-related validity with force plate measures; more difficult stances have higher agreement than do easier ones. The BESS is valid to detect balance deficits where large differences exist (concussion or fatigue). It may not be valid when differences are more subtle. Conclusions: Overall, the BESS has moderate to good reliability to assess static balance. Low levels of reliability have been reported by some authors. The BESS correlates with other measures of balance using testing devices. The BESS can detect balance deficits in participants with concussion and fatigue. BESS scores increase with age and with ankle instability and external ankle bracing. BESS scores improve after training. © 2011 The Author(s).

Stefanov T.S.,National Sports Academy
Folia medica | Year: 2011

The prevalence of the metabolic syndrome (MetS), a cluster of central obesity, hyper/dyslipiemia, hyperglycemia, and hypertension is constantly increasing worldwide. Although, the exact mechanisms underlying the development of the MetS are not completely understood, modern lifestyle of physical inactivity and unhealthy nutrition, obesity, and their interaction with genetic factors are considered largely responsible. It has been convincingly demonstrated that the metabolic syndrome is associated with substantially increased risk for the development of type 2 diabetes mellitus, as well as, with increased cardiovascular disease (CVD) morbidity and mortality. The prevalence of obesity and type 2 diabetes in Bulgaria has dramatically increased in the last decades. For the same period CVD mortality in the country have also gradually increased and Bulgaria is nowadays among the countries with the highest macrovascular disease death rates in Europe. A number of epidemiological studies have demonstrated that the prevalence of the MetS and of its individual components has also increased during the last decades and is nowadays relatively high among the general population in Bulgarian and extremely high among high-risk individuals. Surprisingly, the prevalence of the MetS is also high among the low risk population in the country and most of its components that are independent predictors of CVD mortality are largely undiagnosed. Furthermore, the presence of the MetS is associated with history of myocardial infarction in the country. Although objective data is somewhat scarce, several studies have reported association of the low physical activity level and the unhealthy nutritional habits with the prevalence of cardiometabolic diseases among the Bulgarian population. Taking into account these observations it may be suggested that indeed the high metabolic syndrome prevalence that results as a consequence of unhealthy lifestyle is responsible for the extremely high CVD mortality rates in Bulgaria. Therefore, large-scale screening programmes should be undertaken within this population in combination with health prevention strategies promoting regular physical activity and improvement of nutritional habits.

Bell D.R.,University of Wisconsin - Madison | Oates D.C.,University of North Carolina at Chapel Hill | Clark M.A.,National Sports Academy | Padua D.A.,University of North Carolina at Chapel Hill
Journal of Athletic Training | Year: 2013

Context: Two-dimensional (or medial knee displacement [MKD]) and 3-dimensional (3D) knee valgus are theorized to contribute to anterior cruciate ligament injuries. However, whether these displacements can be improved in the doublelegged squat (DLS) after an exercise intervention is unclear. Objective: To determine if MKD and 3D knee valgus are improved in a DLS after an exercise intervention. Design: Randomized controlled clinical trial. Setting: Research laboratory. Patients or Other Participants: A total of 32 participants were enrolled in this study and were randomly assigned to the control (n =16) or intervention (n = 16) group. During a DLS, all participants demonstrated knee valgus that was corrected with a heel lift. Intervention(s): The intervention group completed 10 sessions of directed exercise that focused on hip and ankle strength and flexibility over a 2- to 3-week period. Main Outcome Measure(s): We assessed MKD and 3D knee valgus during the DLS using an electromagnetic tracking system. Hip strength and ankle-dorsiflexion range of motion were measured. Change scores were calculated for MKD and 3D valgus at 0%, 10%, 20%, 30%, 40%, and 50% phases, and group (2 levels)-by phase (6 levels) repeated-measures analyses of variance were conducted. Independent t tests were used to compare change scores in other variables (α< .05). Results: The MKD decreased from 20% to 50% of the DLS (P=.02) and 3D knee valgus improved from 30% to 50% of the squat phase (P=.001). Ankle-dorsiflexion range of motion (knee extended) increased in the intervention group (P = .009). No other significant findings were observed (P > .05). Conclusions: The intervention reduced MKD and 3D knee valgus during a DLS. The intervention also increased ankle range of motion. Our inclusion criteria might have limited our ability to observe changes in hip strength. © by the National Athletic Trainers' Association, Inc.

Padua D.A.,University of North Carolina at Chapel Hill | Bell D.R.,University of Wisconsin - Madison | Clark M.A.,National Sports Academy
Journal of Athletic Training | Year: 2012

Context: Knee-valgus motion is a potential risk factor for certain lower extremity injuries, including anterior cruciate ligament injury and patellofemoral pain. Identifying neuromuscular characteristics associated with knee-valgus motion, such as hip and lower leg muscle activation, may improve our ability to prevent lower extremity injuries. Objective: We hypothesized that hip and lower leg muscleactivation amplitude would differ among individuals displaying knee valgus (medial knee displacement) during a double-legged squat compared with those who did not display knee valgus. We further suggested that the use of a heel lift would alter lower leg muscle activation and frontal-plane knee motion in those demonstrating medial knee displacement. Design: Descriptive laboratory study. Setting: Research laboratory. Patients or Other Participants: A total of 37 healthy participants were assigned to the control (n = 19) or medialknee-displacement (n=18) group based on their double-legged squat performance. Main Outcome Measure(s): Muscle-activation amplitude for the gluteus maximus, gluteus medius, adductor magnus, medial and lateral gastrocnemius, and tibialis anterior was measured during 2 double-legged squat tasks. The first task consisted of performing a double-legged squat without a heel lift; the second consisted of performing a double-legged squat task with a 2-in (5.08-cm) lift under the heels. Results: Muscle-activation amplitude for the hip adductor, gastrocnemius, and tibialis anterior was greater in those who displayed knee valgus than in those who did not (P < .05). Also, use of heel lifts resulted in decreased activation of the gluteus maximus, hip adductor, gastrocnemius, and tibialis anterior muscles (P < .05). Use of heel lifts also eliminated medially directed frontal-plane knee motion in those displaying medial knee displacement. Conclusions: Medial knee displacement during squatting tasks appears to be associated with increased hip-adductor activation and increased coactivation of the gastrocnemius and tibialis anterior muscles. © by the National Athletic Trainers' Association, Inc.

TO investigate the association of physical activity with insulin resistance and biomarkers of inflammation, coagulation, and fibrinolysis in a population at high risk for type 2 diabetes. A total of 778 subjects from the Risk factors in Impaired Glucose Tolerance for Atherosclerosis and Diabetes (RIAD) study aged 40-70 years were included in the present cross-sectional analysis. Participants classified as having low physical activity (PA) were more insulin resistant in comparison to participants with medium (P = 0.042) and high PA (P = 0.015). Individuals with high physical activity had a significantly lower leucocytes count than individuals with low PA (P = 0.027) and significantly lower hs-CRP and fibrinogen concentrations than individuals with medium (P = 0.011 and P = 0.021) and low physical activity (P = 0.04 and P = 0.007). Although a trend towards a decrease in plasminogen activator inhibitor-1 (PAI-1) and tissue plasminogen activator (tPA) levels with increasing physical activity was present, significant differences were observed only between subjects with high and medium physical activity (P = 0.045 and P = 0.033). In multivariate regression analyses physical activity was an independent determinant of insulin resistance, leucocytes count, hs-CRP, and fibrinogen concentrations. CONCLUSIONs: Physical activity was independently associated with insulin resistance and biomarkers of inflammation, whereas only a tendency towards decreased concentrations of coagulation and fibrinolytic biomarkers with increasing physical activity was observed.

Physical inactivity and excessive food consumption play a major role in the etiology of obesity and type 2 diabetes mellitus (T2DM). The aim of the present study was to investigate the relationship of physical activity (PA) and eating behaviour with obesity and T2DM in citizens of Sofia, Bulgaria. A total of 511 randomly chosen participants completed a validated questionnaire concerning age, body height and weight, medical history, and motivation for a lifestyle change. The Baecke PA questionnaire and the Three Factor Eating Questionnaire were also completed. Body mass index (BMI) was significantly higher among subjects in the lowest compared with the middle (P = 0.002) and with the highest tertile of leisure time PA (P < 0.001), also between the lowest and the highest tertile group of sport PA (P = 0.001). BMI differed significantly in the highest vs. the middle (P = 0.04), as well as vs. the lowest (P= 0.017) tertile of uncontrolled eating behaviour. The prevalence of T2DM was significantly greater in the lowest vs. the middle (P = 0.027) and the highest (P = 0.02) tertile of leisure time PA. In a multiple regression analysis both leisure time PA and uncontrolled eating were independently associated with BMI (beta = -0.13, 95% CI -1.83 to -0.11, P = 0.03 and beta = 0.32, 95% CI 0.23 to 0.44, P < 0.001). We found a strong inverse relationship between the level of PA during leisure time (including sport), BMI, and the prevalence of T2DM. Uncontrolled eating behaviour was also found to have a significant effect on BMI.

DiStefano L.J.,University of Connecticut | Distefano M.J.,Select Physical Therapy | Frank B.S.,University of North Carolina at Chapel Hill | Clark M.A.,National Sports Academy | Padua D.A.,University of North Carolina at Chapel Hill
Journal of Strength and Conditioning Research | Year: 2013

Traditional weight training programs use an exercise prescription strategy that emphasizes improving muscle strength through resistance exercises. Other factors, such as stability, endurance, movement quality, power, flexibility, speed, and agility are also essential elements to improving overall functional performance. Therefore, exercises that incorporate these additional elements may be beneficial additions to traditional resistance training programs. The purpose of the study was to compare the effects of an isolated resistance training program (ISO) and an integrated training program (INT) on movement quality, vertical jump height, agility, muscle strength and endurance, and flexibility. The ISO program consisted of primarily upper and lower extremity progressive resistance exercises. The INT program involved progressive resistance exercises, and core stability, power, and agility exercises. Thirty subjects were cluster randomized to either the ISO (n = 15) or INT (n = 15) training program. Each training group performed their respective programs 2 times per week for 8 weeks. The subjects were assessed before (pretest) and after (posttest) the intervention period using the following assessments: a jump-landing task graded using the Landing Error Scoring System (LESS), vertical jump height, T-test time, push-up and sit-up performance, and the sit-and-reach test. The INT group performed better on the LESS test (pretest: 3.90 ± 1.02, posttest: 3.03 ± 1.02; p = 0.02), faster on the T-test (pretest: 10.35 ± 1.20 seconds, posttest: 9.58 ± 1.02 seconds; p = 0.01), and completed more sit-ups (pretest: 40.20 ± 15.01, posttest: 46.73 ± 14.03; p = 0.045) and push-ups (pretest: 40.67 ± 13.85, posttest: 48.93 ± 15.17; p = 0.05) at posttest compared with pretest, and compared with the ISO group at posttest. Both groups performed more pushups (p = 0.002), jumped higher (p < 0.001), and reached further (p = 0.008) at posttest compared with that at pretest. Performance enhancement programs should use an integrated approach to exercise selection to optimize performance and movement technique benefits. © 2013 National Strength and Conditioning Association.

The objective of the study is to disclose the factor structure and identify the basic factors of the physical development and the specific workability of the 14-15-year-old girls, listed in the compositions of the national basketball teams of Bulgaria (cadets) in the period 2010-2012. Object of the study is 55 basketball players-girls, listed in 3 compositions (2010, 2011 and 2012) of the Bulgarian national team for the respective age group under study. For solving the objective and tasks of the study, data for 21 indicators are registered: physical development - 6 indicators; physical preparedness - 8 indicators and technical-tactical preparedness - 7 indicators. The following methods of research are applied: review study, anthropometry and sport-pedagogical testing. The results of the study are processes mathematically and statistically by: variation analysis, factor analysis and the index method. The results from processing the initial data show that for each of the national teams under study (2010, 2011, 2012), 5 basic factors are extracted, which characterise the specific particularities of the respective selection. The analysis shows that the factors extracted, for the each of the combinations, explain the rather high percentage of the initial dispersion of the physical development and the specific workability of the basketball players-girls. The revealing of the factor structure can help the sport specialists to optimise the educative-training process with the combination under study.

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