0502314552
w.gawronski@medicinasportiva.pl
e-ISSN 1734-2260 from 2005
ISSN 1429-0022 from 1997 till 2004
Indexed in: SportDiscus; EMBASE/Excerpta Medica; Index Copernicus
Medicina Sportiva 2009 vol. 13, Issue 4
Copyright ® 2009 Medicina Sportiva
IMMUNE FUNCTION RESPONSES TO ULTRAMARATHON RACE COMPETITION
David C. Nieman
Read article »
SUDDEN CARDIAC DEATH IN THE MOUNTAIN ENVIRONMENT
Jeremy S Windsor, Jildou Van Der Kaaij, George W Rodway, Rahul Mukherjee and Hugh E Montgomery
Read article »
THE CORRECT INTERPRETATION OF THE SIZE PRINCIPLE AND ITS PRACTICAL APPLICATION TO RESISTANCE TRAINING
Sandee Jungblut
Read article »
INJURY-RISK EVALUATION IN WATER ICE CLIMBING
Volker Schöffl, Isabelle Schöffl, Ulrich Schwarz, Friedrich Hennig, Thomas Küpper
Read article »
LACK OF AN ASSOCIATION BETWEEN CKMM GENOTYPE AND ENDURANCE PERFORMANCE LEVEL IN HISPANIC MARATHON RUNNERS
Juan L. Martínez, Shayan Khorsandi, Robert Sojo, Cristina Martínez, José A. Martín, Juan R. López-Taylor, Thomas D. Fahey, Miguel A. Rivera
Read article »
The relationship between activity energy expenditure, cardiorespiratory fitness, body composition and risk factors in young, lean men and women
Anna Czajkowska, Grażyna Lutosławska, Krzysztof Mazurek, Jadwiga Ambroszkiewicz, Anna Kęska , Piotr Żmijewski
Read article »
Anthropometric and strength characteristics of world-class boulderers
Michail L. Michailov, Lubomir V. Mladenov, Volker R. Schöffl
Read article »
The effect of exercise on glycemic and insulinemic response to two beverages of differing glycemic index
Loes C.A. Jacobs, Tracy L. Perry, Meredith C. Rose, Nancy J. Rehrer
Read article »
CHRONIC DISEASES AND ELITE ATHLETES: AN EPIDEMIOLOGICAL REVIEW
Patrick Laure, Caroline Binsinger
Read article »
AQUAPORIN-1 GENE DNA VARIATION PREDICTS
PERFORMANCE IN HISPANIC MARATHON RUNNERS
Juan L. Martínez, Aleshka Carrión, Maria E. Florián, José A. Martín, Juan R. López-Taylor, Thomas D. Fahey, Miguel A. Rivera
Read article »
Sport related oSteoarticular alterationS in children and adoleScentS
Artur Pupka, Justyna Bogdan, Agnieszka Lepiesza, Aleksandra Rojek, Przemysław P. Szyber
Read article »
IMMUNE FUNCTION RESPONSES TO ULTRAMARATHON RACE COMPETITION
David C. Nieman
Introduction: This article summaries key exercise immunology findings from five years of research on 350 athletes in the 160-km Western States Endurance Run (WSER), a point-to-point trail run in the Sierra Nevada Mountains of northern California.
Methods: WSER athletes provided pre- and post-race blood, urine, and saliva samples, and these were assayed for immune function, inflammation, and oxidative stress outcome measures. Subjects also provided upper respiratory tract infection (URTI), training, and demographic data.
Results: Several key findings from an analysis of the entire 5-year dataset revealed the following:
1. One out of four runners reported sickness during the 2-week period after the 160-km race. Post-race values for granulocyte oxidative burst activity were reduced 50% compared to pre-race. Of all outcome measures, only low post-race sIgA secretion rate was significantly linked to URTI.
2. Variance in plasma cytokine changes during the race was large between WSER finishers, with no male-to-female differences. The cytokine profile measured indicates a strong anti-inflammatory response.
3. Plasma cytokine perturbations were linked to muscle damage and inflammation. Unexpectedly, cytokine variance was unrelated to oxidative stress.
4. Despite the widespread use of ibuprofen by WSER athletes, no beneficial effects were measured for reducing RPE, muscle damage, or DOMS. To the contrary, ibuprofen use was linked to mild endotoxemia, kidney dysfunction, and systemic inflammation.
Conclusions: In general, the WSER data indicate that competitors experience significant immune system stress, reflecting the physiological trauma experienced by the athletes. Long term effects on health have not yet been ascertained.
Key words: cytokines, running, immune function, ibuprofen, oxidative stress, inflammation
Read article »
SUDDEN CARDIAC DEATH IN THE MOUNTAIN ENVIRONMENT
Jeremy S Windsor, Jildou Van Der Kaaij, George W Rodway, Rahul Mukherjee and Hugh E Montgomery
Sudden cardiac death (SCD) is responsible for a considerable number of fatalities in the mountain environment. Victims are often middle aged men with risk factors for coronary artery disease (CAD). Deaths tend to occur during, or immediately after exercise and may be exacerbated by sympathetic stimulation triggered by factors such as anxiety, poor sleep, intercurrent infection, inadequate food intake and dehydration. Myocardial ischaemia, coronary artery spasm and the rupture or erosion of an atherosclerotic plaque have all been cited as potential causes for SCD in the mountain environment. Any strategy intent on reducing the risk of SCD will need to focus upon developing recommendations for those with CAD as well as the larger population who have risk factors for the disease. In addition to preventative strategies, popular ski centres and mountain resorts should also be capable of providing basic care for those who develop an acute coronary syndrome (ACS) and direct victims to appropriate treatment with the utmost urgency.
Key words: sudden cardiac death, altitude, exercise, acute coronary syndrome, myocardial ischaemia, coronary spasm
Read article »
THE CORRECT INTERPRETATION OF THE SIZE PRINCIPLE AND ITS PRACTICAL APPLICATION TO RESISTANCE TRAINING
Sandee Jungblut
Many resistance training experts claim that a very heavy resistance is required to produce optimal strength gains. However, the size principle, motor unit activation studies, and the overwhelming majority of resistance training studies refute that claim. In fact, these studies support the premise that a moderate amount of resistance will produce similar strength gains.
Key words: motor units, effort, recruitment, activation, strength gains
Read article »
INJURY-RISK EVALUATION IN WATER ICE CLIMBING
Volker Schöffl, Isabelle Schöffl, Ulrich Schwarz, Friedrich Hennig, Thomas Küpper
Introduction: Ice-climbing is widely considered to be a hazardous sport with a high risk of injury. To date, there has been no scientific analysis to characterize and reveal the prevalence of injury in this sport. The purpose of this study was to quantify and rate ice-climbing injuries.
Methods: Eighty-eight ice-climbers (water ice) (13 female, 75 male, mean age 34.6 years) from nine countries completed a comprehensive questionnaire on ice-climbing accidents and injuries, climbing frequency and risk taking behaviour. Ice-climbing hours were quantified and injuries rated according to the NACA (National Advisory Committee for Aeronautics) score. To enable comparison to other sports, the injury risk was calculated per 1000 hours of participation in a given sport.
Results: Seventeen athletes (19%) reported a total of 35 overuse syndromes resulting from ice-climbing. Ninety-five injuries were retrospectively reported for a consecutive 3-year period. The incidence and respective grading of the acute injuries were: 67 for NACA 1, 24 for NACA 2, and 4 for NACA 3. Most acute injuries were open wounds (55.2%) and haematomas (21.9%). These injuries occurred 61.3% of the time while lead climbing, 23.8% while following and the rest during belaying, approach or return. The incidence of overuse injury syndromes was 0.77/1000 hours of sports participation. The injury incidence was 4.07/1000hr for NACA 1-3 with 2.87/1000hr in NACA 1, and none in NACA 4-7. Body mass index (BMI) correlated significantly (P<0.05) with an increased risk of injury. Overuse syndromes correlated significantly with training hours (P <0.01), ice-climbing level (P <0.01) and the risk willingness while lead climbing on ice (P<0.01).
Conclusion: Contrary to the popular perception, our study demonstrated that ice-climbing is not a sport with a high risk of injury. All NACA I injuries are of minor medical relevance and would normally not need special treatment or a doctor’s attendance. The results of injury risk per 1000 hours of participation in ice-climbing was comparable to that of indoor competition climbing and to other outdoor sports (hiking, mountain biking, kayaking). The injury risk was also much less than a standard sport such as soccer.
Key words: ice climbing, injury risk, rock climbing, winter sports, sports injury
Read article »
LACK OF AN ASSOCIATION BETWEEN CKMM GENOTYPE AND ENDURANCE PERFORMANCE LEVEL IN HISPANIC MARATHON RUNNERS
Juan L. Martínez, Shayan Khorsandi, Robert Sojo, Cristina Martínez, José A. Martín, Juan R. López-Taylor, Thomas D. Fahey, Miguel A. Rivera
Introduction and aim of the study: Genetics plays a key role in determining endurance performance. We examined the association between a genetic polymorphism at the muscle-specific creatine kinase (CKMM) locus and endurance performance level (EPL) in elite Hispanic marathon runners.
Materials and methods: DNA samples were successfully genotyped from 380 Hispanic marathon runners (men n = 220; women n=160). Cases (n=190; men=110, women=80) were finishers in the top 3 percentile, while controls (n=190; men=110, women=80) were those in the lowest 3 percentile of their respective age and gender. Genotypes were determined by PCR and digestion with NcoI endonuclease.
Results:The three expected genotypes for the CKMM-NcoI were observed in the cases and controls. These genotypes frequencies, within each gender, were in Hardy-Weinberg equilibrium (χ2, P≥0.05) and were not significantly (χ2, P>0.05) different between genders. There was no gender difference (P≥0.05) in the allelic frequencies. The pooled data for both genders revealed no significant differences in genotype (P≥0.05) or allele (P≥0.05) frequencies between cases and controls.
Conclusions: These results replicate the findings of a previous study in Caucasians (Med Sci Sports Exerc. 1997; 29:1444-47) and suggest that the CKMM-NcoI polymorphism is not an important determinant of endurance performance level.
Key words: genetics, chromosome 19, athletes, aerobic capacity, running
Read article »
The relationship between activity energy expenditure, cardiorespiratory fitness, body composition and risk factors in young, lean men and women
Anna Czajkowska, Grażyna Lutosławska, Krzysztof Mazurek, Jadwiga Ambroszkiewicz, Anna Kęska , Piotr Żmijewski
Introduction: Until now it has not been fully elucidated whether metabolic risk is most effectively reduced by increases in self-reported activity energy expenditure (AEE), total body movement, or objectively measured cardiorespiratory fitness (VO2max). On the other hand, data concerning the association between AEE, VO2max, body composition and risk factors in young, lean individuals are incomplete.
Aim of the study: Our study aimed at the examination of the associations between AEE, VO2max, body composition and risk factors in college-aged lean men and women.
Methods: In 76 males with body fat ≤ 20% and 71 females with body fat ≤30% AEE was assessed using Seven-Day-Activity Recall (SDPAR), VO2max was determined during bicycle exercise until exhaustion. Subjects daily energy intake was briefly assessed from 24 h dietary recalls collected over 4 days preceding blood sampling. Blood was withdrawn from the antecubital vein under fasting conditions. Plasma glucose and lipoproteins levels were assayed colorimetrically. Circulating homocysteine was determined using FPIA method. Plasma insulin concentrations were determined using a standard radioimmunoassay.
Results: Exclusively in men AEE was significantly and inversely correlated with percent of body fat (r=-0.270, P<0.001) and markedly and positively correlated with VO2max. In women there was a tendency of higher LBM and lower circulating glucose, in men a tendency of lower plasma homocysteine levels with increasing AEE. In men VO2max was significantly and inversely correlated with body fat (r=-0.340, P<0.003), circulating total cholesterol (r=-.286, P<0.02) and LDL-cholesterol (r=-0.292, P<0.02). In women significant correlations was noted between ¦O2max and surrogate index of insulin resistance – HOMA-IR (r=-0.234, P<0.05). Multiple regression analysis has revealed that neither in men nor in women beneficial metabolic effects of VO2max were mediated by decreases in body fat stores with increasing cardiorespiratory fitness.
Conclusions: In young, lean men, but especially in women AEE effects on metabolic risk factors are minor. On the contrary, VO2max effects on metabolic risk factors seems to be sex-related, in men positively affecting circulating lipoproteins, in women decreasing index of insulin resistance-HOMA-IR. However, in both sexes VO2max exerts positive action irrespectively of the changes in body fat stores.
Key words: males, females, risk factors, physical activity
Read article »
Anthropometric and strength characteristics of world-class boulderers
Michail L. Michailov, Lubomir V. Mladenov, Volker R. Schöffl
Introduction: Anthropometric profiles of lead climbers and boulderers may vary, nevertheless the anthropometric and strength characteristics of world-class boulderers have not yet been analysed. The purpose of this study was to determine these characteristics in elite boulderers competing in Bouldering World Cup.
Methods: Eighteen male (age 25.8 ± 5.1 years) and seven female (age 25.1 ± 5.3 years) competitors were studied at the 2007 Bouldering World Cup in Sofia, Bulgaria. Anthropometric parameters (height, body mass, body mass index, % body fat, % muscle mass and grip strength) were gathered and a sport-specific strength test was performed.
Results: Compared with results in the literature, these adult elite boulderers showed similar characteristics to elite sport climbers. For women the values of the anthropometric variables were: height (cm) 162.6 ± 11.6, body mass (kg) 54 ± 6.8, body mass index 20.4 ± 1.1, % body fat 16.6 ± 3.6, % muscle mass 41.6 ± 4.3, grip strength (kg) 28 ± 8.7, specific strength (kg) 21.6 ± 3.2. For male climbers they were: height (cm) 174.6 ± 5.6, body mass (kg) 67.3 ± 6, body mass index 22 ± 1.4, % body fat 5.8 ± 1.8, % muscle mass 47.4 ± 1.8, grip strength (kg) 58.6 ± 11.4, specific strength (kg) 37.7 ± 6.9. Correlation analysis did not lead to an identification of protrude factors in competition performance. Most of the correlations between the ranking and the measured variables were poor. Moreover the correlations (r) between the rankings from the previous World Cup and the one in Sofia were moderate (r = 0.46, P< 0.05, male rankings).
Conclusion: These world-class competition boulderers differed from elite sport climbers as they had higher percentage of body fat and greater hand strength, while the other anthropometric factors were similar. As the competition performance comprised of a series of elimination rounds whereby boulderers climbed unknown routes without any previous route rehearsal, performance success depended on the mutual action of multiple physical and mental factors. In various conditions different combinations of the decisive factors could be successful. Therefore performance is not stable during different stages of the world cup.
Key words: bouldering, sport climbing, factors of performance
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The effect of exercise on glycemic and insulinemic response to two beverages of differing glycemic index
Loes C.A. Jacobs, Tracy L. Perry, Meredith C. Rose, Nancy J. Rehrer
Introduction: The purpose of this study was to compare the glycemic and insulinemic responses of two beverages with differing glycemic index (GI) ingested immediately prior to exercise and at-rest.
Materials and methods: Nine trained male cyclists (Mean ± SD age 28.8±8.9 y, weight 76.5±4.0 kg and VO2max 57.6±5.7 mL·kg-1·min-1) each performed four randomised crossover treatment trials. A High (78) or Low (43) GI beverage was ingested either immediately prior to 110 min of (70% VO2max) cycling or at-rest.
Results: Exercise decreased blood glucose during the initial 60 min after the consumption of both LGI and HGI beverages (P < 0.001). There was a significantly greater blood glucose response with HGI than with LGI (P < 0.02) regardless of whether the beverages were consumed at-rest or prior to exercise, and a significant interaction between exercise and GI on blood glucose response (P < 0.01). The high variability in insulin response between participants precluded the detection of significant differences in insulin concentrations between any of the trials.
Conclusions: Cycling lowers the blood glucose response to both high and low GI beverages. This effect is more pronounced after ingesting a high GI beverage.
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CHRONIC DISEASES AND ELITE ATHLETES: AN EPIDEMIOLOGICAL REVIEW
Patrick Laure, Caroline Binsinger
Aim of the study: to draw an epidemiological panorama of the link between elite athletes and chronic diseases.
Method: literature review conducted between June and Decembre 2008. Databases used: Medline Pubmed, Pascal, Cochrane Library, BDSP.
Results: apart from traumatology, there are very few epidemiological studies the topic. The incidence of many current chronic diseases, such as coronary artery disease or type 2 diabetes, is lower in elite athletes, especially endurance athlete, than in the general population, excepted for asthma and, undoubtedly, osteoarthritis. Moreover, their standardized mortality ratios are lower too, which results in a lengthened life expectancy.
Discussion: elite athletes naturally have a physiological and genetic profile, which is different from the rest of the population. Beyond physical activity, these elements have to be taken into account for the interpretation of results evoked above. Moreover, may be that the modifications of practice observed recently, such as professionalism, training techniques, or doping behaviors, will have, a few years from here, an impact on the morbidity of these athletes. Lastly, it should be stressed that certain results would deserve to be confirmed, either because the number of study, or the number of participant involved, is reduced, or because the method employed provides a low level of scientific proof (i.e: cohort studies).
Conclusion: it would be advisable to realize prospective epidemiological studies aiming to describe chronic diseases among active or former high level athletes, set up the influence of high level sport practice on health, and evaluate the health-related effects of a regular physical activity in retired high level athletes.
Key-words: elite athletes, health, chronic diseases, epidemiology
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AQUAPORIN-1 GENE DNA VARIATION PREDICTS
PERFORMANCE IN HISPANIC MARATHON RUNNERS
Juan L. Martínez, Aleshka Carrión, Maria E. Florián, José A. Martín, Juan R. López-Taylor, Thomas D. Fahey, Miguel A. Rivera
Introduction and aim of the study: We examined the association between a DNA sequence variant in the aquaporin-1 (AQP1) gene and performance in Hispanic marathon runners.
Materials and methods: DNA samples (N = 784) were obtained from apparently healthy, biologically unrelated, ethnically matched Hispanic marathon runners who participated in international level marathons in Spain and Mexico. Cases (n = 396; men= 225; women=171) finished in the top 3rd percentile for their age and gender, while Controls (n = 388; men=221 women=167) finished in the lowest 3rd percentile. The AQP1 gene DNA sequence variant was detected by the tetra-primer ARMS-PCR procedure which targeted an area of 984 base pairs in the 3’ untranslated region that included the polymorphic site (C - G).
Results: The three expected AQP1 genotypes were observed in both groups (Cases: CC = 15%. GC = 42%, GG = 43%; and Controls: CC = 10%, GC = 39%, GG = 51%). These genotype frequencies were in Hardy-Weinberg equilibrium (X2, P≥0.05) and significantly (X2 = 6.94, P=0.03) different between the Cases and Controls. The Allelic frequencies (Cases; C = 0.36, G = 0.64 and Controls; C = 0.30, G = 0.70) were significantly (X2= 7.55, P=0.005) different between groups. The Odds ratio = 1.35; 95% confidence interval = 1.08 – 1.67, suggested that the C allele was more prevalent in Cases than Controls.
Conclusions: This study showed an association between a DNA sequence variant in the aquaporin-1 gene or in its surrounding region and performance in Hispanic marathon runners.
Key words: genetics, chromosome 7, athletes, aerobic capacity, running, endurance
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Sport related oSteoarticular alterationS in children and adoleScentS
Artur Pupka, Justyna Bogdan, Agnieszka Lepiesza, Aleksandra Rojek, Przemysław P. Szyber
Recent expansion of sport and strength training among children and adolescents inspire for special concern about possible risks associated with this phenomenon. An alarming finding is the growing number of reports of the stress related bones and spine injuries affecting young athletes that may result in significant growth disturbance and deformity. This article elucidates sport related osteoarticular alterations, possible risk injury factors and countermeasure recommendations for children and adolescents training.
Key words: sport, children training, adolescents training, articular, vertebral column, bones
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Indexed in: SportDiscus; EMBASE/Excerpta Medica; Index Copernicus
IMMUNE FUNCTION RESPONSES TO ULTRAMARATHON RACE COMPETITION
Medicina Sportiva 2009 vol. 13, Issue 4
Copyright ® 2009 Medicina Sportiva
David C. Nieman
Read article »
SUDDEN CARDIAC DEATH IN THE MOUNTAIN ENVIRONMENT
Jeremy S Windsor, Jildou Van Der Kaaij, George W Rodway, Rahul Mukherjee and Hugh E Montgomery
Read article »
THE CORRECT INTERPRETATION OF THE SIZE PRINCIPLE AND ITS PRACTICAL APPLICATION TO RESISTANCE TRAINING
Sandee Jungblut
Read article »
INJURY-RISK EVALUATION IN WATER ICE CLIMBING
Volker Schöffl, Isabelle Schöffl, Ulrich Schwarz, Friedrich Hennig, Thomas Küpper
Read article »
LACK OF AN ASSOCIATION BETWEEN CKMM GENOTYPE AND ENDURANCE PERFORMANCE LEVEL IN HISPANIC MARATHON RUNNERS
Juan L. Martínez, Shayan Khorsandi, Robert Sojo, Cristina Martínez, José A. Martín, Juan R. López-Taylor, Thomas D. Fahey, Miguel A. Rivera
Read article »
The relationship between activity energy expenditure, cardiorespiratory fitness, body composition and risk factors in young, lean men and women
Anna Czajkowska, Grażyna Lutosławska, Krzysztof Mazurek, Jadwiga Ambroszkiewicz, Anna Kęska , Piotr Żmijewski
Read article »
Anthropometric and strength characteristics of world-class boulderers
Michail L. Michailov, Lubomir V. Mladenov, Volker R. Schöffl
Read article »
The effect of exercise on glycemic and insulinemic response to two beverages of differing glycemic index
Loes C.A. Jacobs, Tracy L. Perry, Meredith C. Rose, Nancy J. Rehrer
Read article »
CHRONIC DISEASES AND ELITE ATHLETES: AN EPIDEMIOLOGICAL REVIEW
Patrick Laure, Caroline Binsinger
Read article »
AQUAPORIN-1 GENE DNA VARIATION PREDICTS
PERFORMANCE IN HISPANIC MARATHON RUNNERS
Juan L. Martínez, Aleshka Carrión, Maria E. Florián, José A. Martín, Juan R. López-Taylor, Thomas D. Fahey, Miguel A. Rivera
Read article »
Sport related oSteoarticular alterationS in children and adoleScentS
Artur Pupka, Justyna Bogdan, Agnieszka Lepiesza, Aleksandra Rojek, Przemysław P. Szyber
Read article »
IMMUNE FUNCTION RESPONSES TO ULTRAMARATHON RACE COMPETITION
David C. Nieman
Introduction: This article summaries key exercise immunology findings from five years of research on 350 athletes in the 160-km Western States Endurance Run (WSER), a point-to-point trail run in the Sierra Nevada Mountains of northern California.
Methods: WSER athletes provided pre- and post-race blood, urine, and saliva samples, and these were assayed for immune function, inflammation, and oxidative stress outcome measures. Subjects also provided upper respiratory tract infection (URTI), training, and demographic data.
Results: Several key findings from an analysis of the entire 5-year dataset revealed the following:
1. One out of four runners reported sickness during the 2-week period after the 160-km race. Post-race values for granulocyte oxidative burst activity were reduced 50% compared to pre-race. Of all outcome measures, only low post-race sIgA secretion rate was significantly linked to URTI.
2. Variance in plasma cytokine changes during the race was large between WSER finishers, with no male-to-female differences. The cytokine profile measured indicates a strong anti-inflammatory response.
3. Plasma cytokine perturbations were linked to muscle damage and inflammation. Unexpectedly, cytokine variance was unrelated to oxidative stress.
4. Despite the widespread use of ibuprofen by WSER athletes, no beneficial effects were measured for reducing RPE, muscle damage, or DOMS. To the contrary, ibuprofen use was linked to mild endotoxemia, kidney dysfunction, and systemic inflammation.
Conclusions: In general, the WSER data indicate that competitors experience significant immune system stress, reflecting the physiological trauma experienced by the athletes. Long term effects on health have not yet been ascertained.
Key words: cytokines, running, immune function, ibuprofen, oxidative stress, inflammation
Read article »
SUDDEN CARDIAC DEATH IN THE MOUNTAIN ENVIRONMENT
Jeremy S Windsor, Jildou Van Der Kaaij, George W Rodway, Rahul Mukherjee and Hugh E Montgomery
Sudden cardiac death (SCD) is responsible for a considerable number of fatalities in the mountain environment. Victims are often middle aged men with risk factors for coronary artery disease (CAD). Deaths tend to occur during, or immediately after exercise and may be exacerbated by sympathetic stimulation triggered by factors such as anxiety, poor sleep, intercurrent infection, inadequate food intake and dehydration. Myocardial ischaemia, coronary artery spasm and the rupture or erosion of an atherosclerotic plaque have all been cited as potential causes for SCD in the mountain environment. Any strategy intent on reducing the risk of SCD will need to focus upon developing recommendations for those with CAD as well as the larger population who have risk factors for the disease. In addition to preventative strategies, popular ski centres and mountain resorts should also be capable of providing basic care for those who develop an acute coronary syndrome (ACS) and direct victims to appropriate treatment with the utmost urgency.
Key words: sudden cardiac death, altitude, exercise, acute coronary syndrome, myocardial ischaemia, coronary spasm
Read article »
THE CORRECT INTERPRETATION OF THE SIZE PRINCIPLE AND ITS PRACTICAL APPLICATION TO RESISTANCE TRAINING
Sandee Jungblut
Many resistance training experts claim that a very heavy resistance is required to produce optimal strength gains. However, the size principle, motor unit activation studies, and the overwhelming majority of resistance training studies refute that claim. In fact, these studies support the premise that a moderate amount of resistance will produce similar strength gains.
Key words: motor units, effort, recruitment, activation, strength gains
Read article »
INJURY-RISK EVALUATION IN WATER ICE CLIMBING
Volker Schöffl, Isabelle Schöffl, Ulrich Schwarz, Friedrich Hennig, Thomas Küpper
Introduction: Ice-climbing is widely considered to be a hazardous sport with a high risk of injury. To date, there has been no scientific analysis to characterize and reveal the prevalence of injury in this sport. The purpose of this study was to quantify and rate ice-climbing injuries.
Methods: Eighty-eight ice-climbers (water ice) (13 female, 75 male, mean age 34.6 years) from nine countries completed a comprehensive questionnaire on ice-climbing accidents and injuries, climbing frequency and risk taking behaviour. Ice-climbing hours were quantified and injuries rated according to the NACA (National Advisory Committee for Aeronautics) score. To enable comparison to other sports, the injury risk was calculated per 1000 hours of participation in a given sport.
Results: Seventeen athletes (19%) reported a total of 35 overuse syndromes resulting from ice-climbing. Ninety-five injuries were retrospectively reported for a consecutive 3-year period. The incidence and respective grading of the acute injuries were: 67 for NACA 1, 24 for NACA 2, and 4 for NACA 3. Most acute injuries were open wounds (55.2%) and haematomas (21.9%). These injuries occurred 61.3% of the time while lead climbing, 23.8% while following and the rest during belaying, approach or return. The incidence of overuse injury syndromes was 0.77/1000 hours of sports participation. The injury incidence was 4.07/1000hr for NACA 1-3 with 2.87/1000hr in NACA 1, and none in NACA 4-7. Body mass index (BMI) correlated significantly (P<0.05) with an increased risk of injury. Overuse syndromes correlated significantly with training hours (P <0.01), ice-climbing level (P <0.01) and the risk willingness while lead climbing on ice (P<0.01).
Conclusion: Contrary to the popular perception, our study demonstrated that ice-climbing is not a sport with a high risk of injury. All NACA I injuries are of minor medical relevance and would normally not need special treatment or a doctor’s attendance. The results of injury risk per 1000 hours of participation in ice-climbing was comparable to that of indoor competition climbing and to other outdoor sports (hiking, mountain biking, kayaking). The injury risk was also much less than a standard sport such as soccer.
Key words: ice climbing, injury risk, rock climbing, winter sports, sports injury
Read article »
LACK OF AN ASSOCIATION BETWEEN CKMM GENOTYPE AND ENDURANCE PERFORMANCE LEVEL IN HISPANIC MARATHON RUNNERS
Juan L. Martínez, Shayan Khorsandi, Robert Sojo, Cristina Martínez, José A. Martín, Juan R. López-Taylor, Thomas D. Fahey, Miguel A. Rivera
Introduction and aim of the study: Genetics plays a key role in determining endurance performance. We examined the association between a genetic polymorphism at the muscle-specific creatine kinase (CKMM) locus and endurance performance level (EPL) in elite Hispanic marathon runners.
Materials and methods: DNA samples were successfully genotyped from 380 Hispanic marathon runners (men n = 220; women n=160). Cases (n=190; men=110, women=80) were finishers in the top 3 percentile, while controls (n=190; men=110, women=80) were those in the lowest 3 percentile of their respective age and gender. Genotypes were determined by PCR and digestion with NcoI endonuclease.
Results:The three expected genotypes for the CKMM-NcoI were observed in the cases and controls. These genotypes frequencies, within each gender, were in Hardy-Weinberg equilibrium (χ2, P≥0.05) and were not significantly (χ2, P>0.05) different between genders. There was no gender difference (P≥0.05) in the allelic frequencies. The pooled data for both genders revealed no significant differences in genotype (P≥0.05) or allele (P≥0.05) frequencies between cases and controls.
Conclusions: These results replicate the findings of a previous study in Caucasians (Med Sci Sports Exerc. 1997; 29:1444-47) and suggest that the CKMM-NcoI polymorphism is not an important determinant of endurance performance level.
Key words: genetics, chromosome 19, athletes, aerobic capacity, running
Read article »
The relationship between activity energy expenditure, cardiorespiratory fitness, body composition and risk factors in young, lean men and women
Anna Czajkowska, Grażyna Lutosławska, Krzysztof Mazurek, Jadwiga Ambroszkiewicz, Anna Kęska , Piotr Żmijewski
Introduction: Until now it has not been fully elucidated whether metabolic risk is most effectively reduced by increases in self-reported activity energy expenditure (AEE), total body movement, or objectively measured cardiorespiratory fitness (VO2max). On the other hand, data concerning the association between AEE, VO2max, body composition and risk factors in young, lean individuals are incomplete.
Aim of the study: Our study aimed at the examination of the associations between AEE, VO2max, body composition and risk factors in college-aged lean men and women.
Methods: In 76 males with body fat ≤ 20% and 71 females with body fat ≤30% AEE was assessed using Seven-Day-Activity Recall (SDPAR), VO2max was determined during bicycle exercise until exhaustion. Subjects daily energy intake was briefly assessed from 24 h dietary recalls collected over 4 days preceding blood sampling. Blood was withdrawn from the antecubital vein under fasting conditions. Plasma glucose and lipoproteins levels were assayed colorimetrically. Circulating homocysteine was determined using FPIA method. Plasma insulin concentrations were determined using a standard radioimmunoassay.
Results: Exclusively in men AEE was significantly and inversely correlated with percent of body fat (r=-0.270, P<0.001) and markedly and positively correlated with VO2max. In women there was a tendency of higher LBM and lower circulating glucose, in men a tendency of lower plasma homocysteine levels with increasing AEE. In men VO2max was significantly and inversely correlated with body fat (r=-0.340, P<0.003), circulating total cholesterol (r=-.286, P<0.02) and LDL-cholesterol (r=-0.292, P<0.02). In women significant correlations was noted between ¦O2max and surrogate index of insulin resistance – HOMA-IR (r=-0.234, P<0.05). Multiple regression analysis has revealed that neither in men nor in women beneficial metabolic effects of VO2max were mediated by decreases in body fat stores with increasing cardiorespiratory fitness.
Conclusions: In young, lean men, but especially in women AEE effects on metabolic risk factors are minor. On the contrary, VO2max effects on metabolic risk factors seems to be sex-related, in men positively affecting circulating lipoproteins, in women decreasing index of insulin resistance-HOMA-IR. However, in both sexes VO2max exerts positive action irrespectively of the changes in body fat stores.
Key words: males, females, risk factors, physical activity
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Anthropometric and strength characteristics of world-class boulderers
Michail L. Michailov, Lubomir V. Mladenov, Volker R. Schöffl
Introduction: Anthropometric profiles of lead climbers and boulderers may vary, nevertheless the anthropometric and strength characteristics of world-class boulderers have not yet been analysed. The purpose of this study was to determine these characteristics in elite boulderers competing in Bouldering World Cup.
Methods: Eighteen male (age 25.8 ± 5.1 years) and seven female (age 25.1 ± 5.3 years) competitors were studied at the 2007 Bouldering World Cup in Sofia, Bulgaria. Anthropometric parameters (height, body mass, body mass index, % body fat, % muscle mass and grip strength) were gathered and a sport-specific strength test was performed.
Results: Compared with results in the literature, these adult elite boulderers showed similar characteristics to elite sport climbers. For women the values of the anthropometric variables were: height (cm) 162.6 ± 11.6, body mass (kg) 54 ± 6.8, body mass index 20.4 ± 1.1, % body fat 16.6 ± 3.6, % muscle mass 41.6 ± 4.3, grip strength (kg) 28 ± 8.7, specific strength (kg) 21.6 ± 3.2. For male climbers they were: height (cm) 174.6 ± 5.6, body mass (kg) 67.3 ± 6, body mass index 22 ± 1.4, % body fat 5.8 ± 1.8, % muscle mass 47.4 ± 1.8, grip strength (kg) 58.6 ± 11.4, specific strength (kg) 37.7 ± 6.9. Correlation analysis did not lead to an identification of protrude factors in competition performance. Most of the correlations between the ranking and the measured variables were poor. Moreover the correlations (r) between the rankings from the previous World Cup and the one in Sofia were moderate (r = 0.46, P< 0.05, male rankings).
Conclusion: These world-class competition boulderers differed from elite sport climbers as they had higher percentage of body fat and greater hand strength, while the other anthropometric factors were similar. As the competition performance comprised of a series of elimination rounds whereby boulderers climbed unknown routes without any previous route rehearsal, performance success depended on the mutual action of multiple physical and mental factors. In various conditions different combinations of the decisive factors could be successful. Therefore performance is not stable during different stages of the world cup.
Key words: bouldering, sport climbing, factors of performance
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The effect of exercise on glycemic and insulinemic response to two beverages of differing glycemic index
Loes C.A. Jacobs, Tracy L. Perry, Meredith C. Rose, Nancy J. Rehrer
Introduction: The purpose of this study was to compare the glycemic and insulinemic responses of two beverages with differing glycemic index (GI) ingested immediately prior to exercise and at-rest.
Materials and methods: Nine trained male cyclists (Mean ± SD age 28.8±8.9 y, weight 76.5±4.0 kg and VO2max 57.6±5.7 mL·kg-1·min-1) each performed four randomised crossover treatment trials. A High (78) or Low (43) GI beverage was ingested either immediately prior to 110 min of (70% VO2max) cycling or at-rest.
Results: Exercise decreased blood glucose during the initial 60 min after the consumption of both LGI and HGI beverages (P < 0.001). There was a significantly greater blood glucose response with HGI than with LGI (P < 0.02) regardless of whether the beverages were consumed at-rest or prior to exercise, and a significant interaction between exercise and GI on blood glucose response (P < 0.01). The high variability in insulin response between participants precluded the detection of significant differences in insulin concentrations between any of the trials.
Conclusions: Cycling lowers the blood glucose response to both high and low GI beverages. This effect is more pronounced after ingesting a high GI beverage.
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CHRONIC DISEASES AND ELITE ATHLETES: AN EPIDEMIOLOGICAL REVIEW
Patrick Laure, Caroline Binsinger
Aim of the study: to draw an epidemiological panorama of the link between elite athletes and chronic diseases.
Method: literature review conducted between June and Decembre 2008. Databases used: Medline Pubmed, Pascal, Cochrane Library, BDSP.
Results: apart from traumatology, there are very few epidemiological studies the topic. The incidence of many current chronic diseases, such as coronary artery disease or type 2 diabetes, is lower in elite athletes, especially endurance athlete, than in the general population, excepted for asthma and, undoubtedly, osteoarthritis. Moreover, their standardized mortality ratios are lower too, which results in a lengthened life expectancy.
Discussion: elite athletes naturally have a physiological and genetic profile, which is different from the rest of the population. Beyond physical activity, these elements have to be taken into account for the interpretation of results evoked above. Moreover, may be that the modifications of practice observed recently, such as professionalism, training techniques, or doping behaviors, will have, a few years from here, an impact on the morbidity of these athletes. Lastly, it should be stressed that certain results would deserve to be confirmed, either because the number of study, or the number of participant involved, is reduced, or because the method employed provides a low level of scientific proof (i.e: cohort studies).
Conclusion: it would be advisable to realize prospective epidemiological studies aiming to describe chronic diseases among active or former high level athletes, set up the influence of high level sport practice on health, and evaluate the health-related effects of a regular physical activity in retired high level athletes.
Key-words: elite athletes, health, chronic diseases, epidemiology
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AQUAPORIN-1 GENE DNA VARIATION PREDICTS
PERFORMANCE IN HISPANIC MARATHON RUNNERS
Juan L. Martínez, Aleshka Carrión, Maria E. Florián, José A. Martín, Juan R. López-Taylor, Thomas D. Fahey, Miguel A. Rivera
Introduction and aim of the study: We examined the association between a DNA sequence variant in the aquaporin-1 (AQP1) gene and performance in Hispanic marathon runners.
Materials and methods: DNA samples (N = 784) were obtained from apparently healthy, biologically unrelated, ethnically matched Hispanic marathon runners who participated in international level marathons in Spain and Mexico. Cases (n = 396; men= 225; women=171) finished in the top 3rd percentile for their age and gender, while Controls (n = 388; men=221 women=167) finished in the lowest 3rd percentile. The AQP1 gene DNA sequence variant was detected by the tetra-primer ARMS-PCR procedure which targeted an area of 984 base pairs in the 3’ untranslated region that included the polymorphic site (C - G).
Results: The three expected AQP1 genotypes were observed in both groups (Cases: CC = 15%. GC = 42%, GG = 43%; and Controls: CC = 10%, GC = 39%, GG = 51%). These genotype frequencies were in Hardy-Weinberg equilibrium (X2, P≥0.05) and significantly (X2 = 6.94, P=0.03) different between the Cases and Controls. The Allelic frequencies (Cases; C = 0.36, G = 0.64 and Controls; C = 0.30, G = 0.70) were significantly (X2= 7.55, P=0.005) different between groups. The Odds ratio = 1.35; 95% confidence interval = 1.08 – 1.67, suggested that the C allele was more prevalent in Cases than Controls.
Conclusions: This study showed an association between a DNA sequence variant in the aquaporin-1 gene or in its surrounding region and performance in Hispanic marathon runners.
Key words: genetics, chromosome 7, athletes, aerobic capacity, running, endurance
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Sport related oSteoarticular alterationS in children and adoleScentS
Artur Pupka, Justyna Bogdan, Agnieszka Lepiesza, Aleksandra Rojek, Przemysław P. Szyber
Recent expansion of sport and strength training among children and adolescents inspire for special concern about possible risks associated with this phenomenon. An alarming finding is the growing number of reports of the stress related bones and spine injuries affecting young athletes that may result in significant growth disturbance and deformity. This article elucidates sport related osteoarticular alterations, possible risk injury factors and countermeasure recommendations for children and adolescents training.
Key words: sport, children training, adolescents training, articular, vertebral column, bones
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