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Sofia, Bulgaria

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).

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.

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.

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.

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