Int J Sports Med. 2010 Mar;31(3):148-153. Epub 2010 Feb 15.
Deltoid Muscle Characteristics in Wrestlers.
Mandroukas A, Heller J, Metaxas TI, Christoulas K, Vamvakoudis E, Stefanidis P, Papavasileiou A, Kotoglou K, Balasas D, Ekblom B, Mandroukas K.
Laboratory of Ergophysiology-Ergometry, Department of Physical Education and Sports Science, Aristotle University of Thessaloniki, Greece.
The purpose of the present study was to investigate the deltoid muscle characteristics of wrestlers. Nine Greco-Roman competitive male wrestlers (mean age 20.1+/-2.7 yrs, height 175+/-0.6 cm, weight 83.2+/-12.5 kg, years of training 7.6+/-2.7 yrs) participated in this study. Six male healthy sedentary students (mean age 21.2+/-0.9 yrs, height 180+/-0.3 cm, weight 80.1+/-9.4 kg) served as controls. Muscle fibre distribution, cross-sectional area (CSA), as well as satellite cells, myonuclei and capillary density per muscle fibre area were determined by immunohistochemistry. Myosin heavy chain MHC isoform composition of single fibres was determined with protein electrophoresis. Immunohistochemical analysis showed that muscle fibre distribution of the MHC I and IIA were significantly higher in wrestlers than in controls (p<0.05). Electrophoretic analysis of single fibres revealed a significantly higher proportion of fibres containing MHC I and IIC in wrestlers (p<0.05). The mean CSA of type IIA fibres and the number of myonuclei per type II was significantly higher in wrestlers (p<0.05). We also found that the number of satellite cells was 2.5 fold higher in wrestlers than in the control group. This study suggests that the observed muscle fibre profile in the deltoid of wrestlers may represent an adaptation based on the specific mechanical and biochemical demands of the long-term training in Greco-Roman wrestling.
http://grupodestudoslutas.blogspot.com
Inscrever-se
Postagens
Comentários
quarta-feira, 10 de março de 2010
Mais uma investigação sobre boxe no Wii
Ann Behav Med. 2010 Feb 19. [Epub ahead of print]
Motivation and Physiologic Responses of Playing a Physically Interactive Video Game Relative to a Sedentary Alternative in Children.
Penko AL, Barkley JE.
The School of Exercise Leisure and Sport, Kent State University, Kent, OH, 44240, USA, penkoa@ccf.org.
Abstract
Background While there is emerging research outlining the physiologic cost of the physically interactive Nintendo Wii, there are no evaluations of the relative reinforcing value (RRV) of the Wii versus a sedentary alternative. Purpose The purpose of this study is to evaluate the physiologic cost, RRV, and liking of playing Wii Sports Boxing (Wii) versus a traditional sedentary video game (SVG) in 11 lean and 13 overweight/obese 8- to 12-yearold children. Methods Heart rate (HR) and VO2 were assessed during rest, treadmill walking, and playing an SVG and Wii using a counterbalance design. Liking was assessed during treadmill walking and video game play. RRV was assessed for Wii versus SVG.
Results Average HR, VO2, and liking were significantly greater for Nintendo Wii (p≤0.001 for all) than all other conditions. Lean children displayed a greater (p<0.001)peak responding for access to Wii relative to the SVG while overweight/obese children did not (p≥0.16). Conclusion Wii was a well-liked activity of greater physiologic intensity than both the SVG and treadmill walking. Lean children were more motivated while overweight/obese children were equally as motivated to play Wii relative to the SVG.
Motivation and Physiologic Responses of Playing a Physically Interactive Video Game Relative to a Sedentary Alternative in Children.
Penko AL, Barkley JE.
The School of Exercise Leisure and Sport, Kent State University, Kent, OH, 44240, USA, penkoa@ccf.org.
Abstract
Background While there is emerging research outlining the physiologic cost of the physically interactive Nintendo Wii, there are no evaluations of the relative reinforcing value (RRV) of the Wii versus a sedentary alternative. Purpose The purpose of this study is to evaluate the physiologic cost, RRV, and liking of playing Wii Sports Boxing (Wii) versus a traditional sedentary video game (SVG) in 11 lean and 13 overweight/obese 8- to 12-yearold children. Methods Heart rate (HR) and VO2 were assessed during rest, treadmill walking, and playing an SVG and Wii using a counterbalance design. Liking was assessed during treadmill walking and video game play. RRV was assessed for Wii versus SVG.
Results Average HR, VO2, and liking were significantly greater for Nintendo Wii (p≤0.001 for all) than all other conditions. Lean children displayed a greater (p<0.001)peak responding for access to Wii relative to the SVG while overweight/obese children did not (p≥0.16). Conclusion Wii was a well-liked activity of greater physiologic intensity than both the SVG and treadmill walking. Lean children were more motivated while overweight/obese children were equally as motivated to play Wii relative to the SVG.
Artigo interessante sobre estudo de caso envolvendo perda de peso de boxeador
Int J Sport Nutr Exerc Metab. 2010 Feb;20(1):80-5.
Making the weight: a case study from professional boxing.
Morton JP, Robertson C, Sutton L, Maclaren DP.
Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK.
Professional boxing is a combat sport categorized into a series of weight classes. Given the sport's underpinning culture, boxers' typical approach to "making weight" is usually via severe acute and/or chronic energy restriction and dehydration. Such practices have implications for physical performance and also carry health risks. This article provides a case-study account outlining a more structured and gradual approach to helping a professional male boxer make weight for the 59-kg superfeatherweight division. Over a 12-week period, the client athlete adhered to a daily diet approximately equivalent to his resting metabolic rate (6-7 MJ; 40% carbohydrate, 38% protein, 22% fat). Average body-mass loss was 0.9 +/- 0.4 kg/wk, equating to a total loss of 9.4 kg. This weight loss resulted in a decrease in percent body fat from 12.1% to 7.0%. In the 30 hr between weigh-in and competition, the client consumed a high-carbohydrate diet (12 g/kg body mass) supported by appropriate hydration strategies and subsequently entered the ring at a fighting weight of 63.2 kg. This nutritional strategy represented a major change in the client's habitual weight-making practices and did not rely on any form of intended dehydration during the training period or before weighing in. The intervention demonstrates that a more gradual approach to making weight in professional boxing can be successfully achieved via a combination of restricted energy intake and increased energy expenditure, providing there is willingness on the part of the athlete and coaches involved to adopt novel practices.
Making the weight: a case study from professional boxing.
Morton JP, Robertson C, Sutton L, Maclaren DP.
Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK.
Professional boxing is a combat sport categorized into a series of weight classes. Given the sport's underpinning culture, boxers' typical approach to "making weight" is usually via severe acute and/or chronic energy restriction and dehydration. Such practices have implications for physical performance and also carry health risks. This article provides a case-study account outlining a more structured and gradual approach to helping a professional male boxer make weight for the 59-kg superfeatherweight division. Over a 12-week period, the client athlete adhered to a daily diet approximately equivalent to his resting metabolic rate (6-7 MJ; 40% carbohydrate, 38% protein, 22% fat). Average body-mass loss was 0.9 +/- 0.4 kg/wk, equating to a total loss of 9.4 kg. This weight loss resulted in a decrease in percent body fat from 12.1% to 7.0%. In the 30 hr between weigh-in and competition, the client consumed a high-carbohydrate diet (12 g/kg body mass) supported by appropriate hydration strategies and subsequently entered the ring at a fighting weight of 63.2 kg. This nutritional strategy represented a major change in the client's habitual weight-making practices and did not rely on any form of intended dehydration during the training period or before weighing in. The intervention demonstrates that a more gradual approach to making weight in professional boxing can be successfully achieved via a combination of restricted energy intake and increased energy expenditure, providing there is willingness on the part of the athlete and coaches involved to adopt novel practices.
Assinar:
Postagens (Atom)