Pediatrics. 2011 Aug 28. [Epub ahead of print]
Policy Statement--Boxing Participation by Children and Adolescents.
AMERICAN ACADEMY OF PEDIATRICS; COUNCIL ON SPORTS MEDICINE AND FITNESS; CANADIAN PAEDIATRIC SOCIETY; HEALTHY ACTIVE LIVING AND SPORTS MEDICINE COMMITTEE.
Abstract
Thousands of boys and girls younger than 19 years participate in boxing in North America. Although boxing provides benefits for participants, including exercise, self-discipline, and self-confidence, the sport of boxing encourages and rewards deliberate blows to the head and face. Participants in boxing are at risk of head, face, and neck injuries, including chronic and even fatal neurologic injuries. Concussions are one of the most common injuries that occur with boxing. Because of the risk of head and facial injuries, the American Academy of Pediatrics and the Canadian Paediatric Society oppose boxing as a sport for children and adolescents. These organizations recommend that physicians vigorously oppose boxing in youth and encourage patients to participate in alternative sports in which intentional head blows are not central to the sport.
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Quem sou eu
- Emerson Franchini
- São Paulo, São Paulo, Brazil
- Professor da EEFE-USP; Praticante e Pesquisador de Judô; Preparador físico de atletas de modalidades esportivas de combate.
Arquivo do blog
- ► 2012 (168)
- ► 2011 (203)
terça-feira, 30 de agosto de 2011
domingo, 28 de agosto de 2011
Mudanças nos fluídos corporais e na força isométrica máxima em atletas de judô
J Strength Cond Res. 2011 Sep;25(9):2488-2495.
Relationship Between Changes in Total-Body Water and Fluid Distribution With Maximal Forearm Strength in Elite Judo Athletes.
Silva AM, Fields DA, Heymsfield SB, Sardinha LB.
1Exercise and Health Laboratory, Faculty of Human Kinetics-Technical University of Lisbon, Lisbon, Portugal; 2Department of Pediatrics, Children's Medical Research Institute's Metabolic Research Program, University of Oklahoma Health Science Center, Oklahoma City, Oklahoma; and 3Pennington Biomedical Research Foundation, Baton Rouge, Louisiana.
Abstract
Silva, AM, Fields, DA, Heymsfield, SB, and Sardinha, LB. Relationship between changes in total-body water and fluid distribution with maximal forearm strength in elite judo athletes. J Strength Cond Res 25(9): 2488-2495, 2011-Among judo athletes, strong grip strength is crucial for performing offensive and defensive maneuvers that rely predominantly on forearm maximal strength (FMS). The study aims were to evaluate changes in total-body water (TBW) and its compartments (extracellular water [ECW] and intracellular water [ICW]) and their relationship with loss of FMS in elite judo athletes. At baseline (weight stability), 27 male elite athletes were evaluated (age: 23.2 ± 2.8 years) and again evaluated 1-3 days before competition. Athletes were free to gain or lose weight based upon their specific competition needs. Using dilution techniques (deuterium and bromide), TBW and ECW were estimated, and ICW was calculated (ICW = TBW - ECW). Fat, fat-free mass, and appendicular lean soft tissue (LST) were assessed by dual-energy x-ray absorptiometry. Handgrip was used to assess FMS. Using a reduction of 2% as a representative outcome for decreased FMS, 10 athletes were identified as having lost FMS, whereas 17 changed <2% or gained. Comparison of means and logistic regression analysis were performed. Results from baseline to before competition indicated that those who lost ≥2% of FMS significantly decreased TBW and ICW by -2.7 ± 3.0 and -4.4 ± 4.2%, respectively. The groups differed in ICW changes (-4.4 ± 4.2 vs. 1.9 ± 6.1%), respectively, for those who lost FMS by ≥2%. The ICW changes, but not in TBW or ECW, significantly predicted the risk of losing FMS (β = 0.206; p = 0.027), even adjusting for weight and arm LST changes. These findings indicated that reductions in ICW increased the risk of losing grip strength in elite judo athletes.
Relationship Between Changes in Total-Body Water and Fluid Distribution With Maximal Forearm Strength in Elite Judo Athletes.
Silva AM, Fields DA, Heymsfield SB, Sardinha LB.
1Exercise and Health Laboratory, Faculty of Human Kinetics-Technical University of Lisbon, Lisbon, Portugal; 2Department of Pediatrics, Children's Medical Research Institute's Metabolic Research Program, University of Oklahoma Health Science Center, Oklahoma City, Oklahoma; and 3Pennington Biomedical Research Foundation, Baton Rouge, Louisiana.
Abstract
Silva, AM, Fields, DA, Heymsfield, SB, and Sardinha, LB. Relationship between changes in total-body water and fluid distribution with maximal forearm strength in elite judo athletes. J Strength Cond Res 25(9): 2488-2495, 2011-Among judo athletes, strong grip strength is crucial for performing offensive and defensive maneuvers that rely predominantly on forearm maximal strength (FMS). The study aims were to evaluate changes in total-body water (TBW) and its compartments (extracellular water [ECW] and intracellular water [ICW]) and their relationship with loss of FMS in elite judo athletes. At baseline (weight stability), 27 male elite athletes were evaluated (age: 23.2 ± 2.8 years) and again evaluated 1-3 days before competition. Athletes were free to gain or lose weight based upon their specific competition needs. Using dilution techniques (deuterium and bromide), TBW and ECW were estimated, and ICW was calculated (ICW = TBW - ECW). Fat, fat-free mass, and appendicular lean soft tissue (LST) were assessed by dual-energy x-ray absorptiometry. Handgrip was used to assess FMS. Using a reduction of 2% as a representative outcome for decreased FMS, 10 athletes were identified as having lost FMS, whereas 17 changed <2% or gained. Comparison of means and logistic regression analysis were performed. Results from baseline to before competition indicated that those who lost ≥2% of FMS significantly decreased TBW and ICW by -2.7 ± 3.0 and -4.4 ± 4.2%, respectively. The groups differed in ICW changes (-4.4 ± 4.2 vs. 1.9 ± 6.1%), respectively, for those who lost FMS by ≥2%. The ICW changes, but not in TBW or ECW, significantly predicted the risk of losing FMS (β = 0.206; p = 0.027), even adjusting for weight and arm LST changes. These findings indicated that reductions in ICW increased the risk of losing grip strength in elite judo athletes.
Estresse oxidativo em judocas e indivíduos sedentários
J Strength Cond Res. 2011 Sep;25(9):2400-2409.
Antioxidant Status and Oxidative Stress at Rest and in Response to Acute Exercise in Judokas and Sedentary Men.
Abed KE, Rebai H, Bloomer RJ, Trabelsi K, Masmoudi L, Zbidi A, Sahnoun Z, Hakim A, Tabka Z.
1Laboratory of Cardio-Circulatory, Respiratory, Metabolic, and Hormonal Adaptations to the Muscular Exercise, Faculty of Medicine Ibn El Jazzar, Sousse, Tunisia; 2Laboratory of Pharmacology, Faculty of Medicine, Sfax, Tunisia; and 3Cardiorespiratory/Metabolic Laboratory, University of Memphis, Memphis, Tennessee.
Abstract
El Abed, K, Rebai, H, Bloomer, RJ, Trabelsi, K, Masmoudi, L, Zbidi, A, Sahnoun, Z, Hakim, and A Tabka, Z. Antioxidant status and oxidative stress at rest and in response to acute exercise in judokas and sedentary men. J Strength Cond Res 25(9): 2400-2409, 2011. It is well recognized that acute strenuous exercise is accompanied by an increase in free-radical production and subsequent oxidative stress, in addition to changes in blood antioxidant status. Chronic exercise provides protection against exercise-induced oxidative stress by upregulating endogenous antioxidant defense systems. Little is known regarding the protective effect afforded by judo exercise. Therefore, we determined antioxidant and oxidative stress biomarkers at rest and in response to acute exercise in 10 competitive judokas and 10 sedentary subjects after mixed exercise (anaerobic followed by aerobic). The subjects performed a Wingate test, followed by 30 minutes of aerobic exercise performed at 60% of maximal aerobic power. Blood samples were taken, by an intravenous catheter, at rest (R), immediately after the physical exercise (P0), and at 5 (P5), 10 (P10), and 20 (P20) minutes postexercise. The measured parameters included the activity of the antioxidant enzymes superoxide dismutase, glutathione peroxidase, and glutathione reductase, in addition to α-tocopherol, and total antioxidant status. Malondialdehyde was measured as a representation of lipid peroxidation. At rest, the judokas had higher values for all antioxidant and oxidative stress markers as compared to the sedentary subjects (p < 0.05). Plasma concentrations of all parameters except for α-tocopherol increased significantly above resting values for both the judokas and sedentary subjects (p < 0.05) and remained elevated at 20 minutes postexercise. A significant postexercise decrease was observed for α-tocopherol (p < 0.05) at P20 for judokas and at P5 for sedentary subjects. These data indicate that competitive judo athletes have higher endogenous antioxidant protection compared to sedentary subjects. However, both groups of subjects experience an increase in exercise-induced oxidative stress that is not different.
Antioxidant Status and Oxidative Stress at Rest and in Response to Acute Exercise in Judokas and Sedentary Men.
Abed KE, Rebai H, Bloomer RJ, Trabelsi K, Masmoudi L, Zbidi A, Sahnoun Z, Hakim A, Tabka Z.
1Laboratory of Cardio-Circulatory, Respiratory, Metabolic, and Hormonal Adaptations to the Muscular Exercise, Faculty of Medicine Ibn El Jazzar, Sousse, Tunisia; 2Laboratory of Pharmacology, Faculty of Medicine, Sfax, Tunisia; and 3Cardiorespiratory/Metabolic Laboratory, University of Memphis, Memphis, Tennessee.
Abstract
El Abed, K, Rebai, H, Bloomer, RJ, Trabelsi, K, Masmoudi, L, Zbidi, A, Sahnoun, Z, Hakim, and A Tabka, Z. Antioxidant status and oxidative stress at rest and in response to acute exercise in judokas and sedentary men. J Strength Cond Res 25(9): 2400-2409, 2011. It is well recognized that acute strenuous exercise is accompanied by an increase in free-radical production and subsequent oxidative stress, in addition to changes in blood antioxidant status. Chronic exercise provides protection against exercise-induced oxidative stress by upregulating endogenous antioxidant defense systems. Little is known regarding the protective effect afforded by judo exercise. Therefore, we determined antioxidant and oxidative stress biomarkers at rest and in response to acute exercise in 10 competitive judokas and 10 sedentary subjects after mixed exercise (anaerobic followed by aerobic). The subjects performed a Wingate test, followed by 30 minutes of aerobic exercise performed at 60% of maximal aerobic power. Blood samples were taken, by an intravenous catheter, at rest (R), immediately after the physical exercise (P0), and at 5 (P5), 10 (P10), and 20 (P20) minutes postexercise. The measured parameters included the activity of the antioxidant enzymes superoxide dismutase, glutathione peroxidase, and glutathione reductase, in addition to α-tocopherol, and total antioxidant status. Malondialdehyde was measured as a representation of lipid peroxidation. At rest, the judokas had higher values for all antioxidant and oxidative stress markers as compared to the sedentary subjects (p < 0.05). Plasma concentrations of all parameters except for α-tocopherol increased significantly above resting values for both the judokas and sedentary subjects (p < 0.05) and remained elevated at 20 minutes postexercise. A significant postexercise decrease was observed for α-tocopherol (p < 0.05) at P20 for judokas and at P5 for sedentary subjects. These data indicate that competitive judo athletes have higher endogenous antioxidant protection compared to sedentary subjects. However, both groups of subjects experience an increase in exercise-induced oxidative stress that is not different.
sábado, 27 de agosto de 2011
segunda-feira, 22 de agosto de 2011
Artigo na Science indica uso de artes marciais para melhoria da função executiva de crianças
Science. 2011 Aug 19;333(6045):959-64.
Interventions shown to aid executive function development in children 4 to 12 years old.
Diamond A, Lee K.
SourceUniversity of British Columbia and Children's Hospital, Vancouver, BC V6T 2A1, Canada. adele.diamond@ubc.ca
Abstract
To be successful takes creativity, flexibility, self-control, and discipline. Central to all those are executive functions, including mentally playing with ideas, giving a considered rather than an impulsive response, and staying focused. Diverse activities have been shown to improve children's executive functions: computerized training, noncomputerized games, aerobics, martial arts, yoga, mindfulness, and school curricula. All successful programs involve repeated practice and progressively increase the challenge to executive functions. Children with worse executive functions benefit most from these activities; thus, early executive-function training may avert widening achievement gaps later. To improve executive functions, focusing narrowly on them may not be as effective as also addressing emotional and social development (as do curricula that improve executive functions) and physical development (shown by positive effects of aerobics, martial arts, and yoga).
Interventions shown to aid executive function development in children 4 to 12 years old.
Diamond A, Lee K.
SourceUniversity of British Columbia and Children's Hospital, Vancouver, BC V6T 2A1, Canada. adele.diamond@ubc.ca
Abstract
To be successful takes creativity, flexibility, self-control, and discipline. Central to all those are executive functions, including mentally playing with ideas, giving a considered rather than an impulsive response, and staying focused. Diverse activities have been shown to improve children's executive functions: computerized training, noncomputerized games, aerobics, martial arts, yoga, mindfulness, and school curricula. All successful programs involve repeated practice and progressively increase the challenge to executive functions. Children with worse executive functions benefit most from these activities; thus, early executive-function training may avert widening achievement gaps later. To improve executive functions, focusing narrowly on them may not be as effective as also addressing emotional and social development (as do curricula that improve executive functions) and physical development (shown by positive effects of aerobics, martial arts, and yoga).
Perda de peso e uso de suplementos entre wrestlers iranianos
Patterns of weight loss and supplement consumption of male wrestlers in Tehran
Ramin Kordi1*, Vahid Ziaee1, Mohsen Rostami1, William A Wallace2
Abstract
Background: To evaluate the weight loss behavior of male wrestlers in Tehran
Methods: This study was a population-based cross sectional survey. Subjects were 436 wrestlers randomly selected from the wrestling clubs in Tehran employing cluster sample setting method. Subjects were interviewed based on a designed questionnaire. Body fat levels were measured based on skin fold measurements.
Results: Weight loss methods practiced by 62% of all subjects during the previous year employing rapid (≤7 days before the matches) and gradual (>7 days before the matches) weight reduction methods (73% and 34% of wrestlers who reduced their weight respectively). In addition, opinions on weight reduction, the methods of weight loss used, and the side effects of the weight loss practices as well as consumption of supplements among the subjects were reported in this study. The mean percentage of body fat of subjects was 15.9%. Conclusions: Rapid weight loss for matches and the use of unsafe methods of weight reduction such as fasting, and fluid reduction methods as well as acute side effects of weight loss were prevalent among wrestlers in Tehran. Some preventive measures including education and new rules such as scheduling weigh-ins immediately prior to the competitions and mat-side weigh-in are needed to prevent these unhealthy practices. The weight loss behaviors of these wrestlers should be changed from using dehydration methods to using gradual methods of weight loss.
http://www.springerlink.com/content/c48727205u116275/fulltext.pdf
Ramin Kordi1*, Vahid Ziaee1, Mohsen Rostami1, William A Wallace2
Abstract
Background: To evaluate the weight loss behavior of male wrestlers in Tehran
Methods: This study was a population-based cross sectional survey. Subjects were 436 wrestlers randomly selected from the wrestling clubs in Tehran employing cluster sample setting method. Subjects were interviewed based on a designed questionnaire. Body fat levels were measured based on skin fold measurements.
Results: Weight loss methods practiced by 62% of all subjects during the previous year employing rapid (≤7 days before the matches) and gradual (>7 days before the matches) weight reduction methods (73% and 34% of wrestlers who reduced their weight respectively). In addition, opinions on weight reduction, the methods of weight loss used, and the side effects of the weight loss practices as well as consumption of supplements among the subjects were reported in this study. The mean percentage of body fat of subjects was 15.9%. Conclusions: Rapid weight loss for matches and the use of unsafe methods of weight reduction such as fasting, and fluid reduction methods as well as acute side effects of weight loss were prevalent among wrestlers in Tehran. Some preventive measures including education and new rules such as scheduling weigh-ins immediately prior to the competitions and mat-side weigh-in are needed to prevent these unhealthy practices. The weight loss behaviors of these wrestlers should be changed from using dehydration methods to using gradual methods of weight loss.
http://www.springerlink.com/content/c48727205u116275/fulltext.pdf
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