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Training and testing the top-class soccer player
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Friday 23 October Papers / Journal of Science and Medicine in Sport 19S (2015) e57–e87
harmful compound peroxynitrite. In addition, high levels of ROS can lead to an alteration (uncoupling) of nitric oxide synthase, whereby the enzyme produces ROS instead of NO. Evidence for an interaction between NO and ROS has been provided in studies on aged individuals who are believed to have elevated levels of ROS in the vascular system. Such studies show that infusion of antioxidants into the blood can improve the level and function of NO. On the other hand ROS have been shown to be important signaling molecules for adaptations in response to exercise training. There is substantial evidence for that intake of antioxidants in connection with endurance training can attenuate and even abolish cardiovascular adaptations in response to training. This lecture focuses on the role of NO and ROS for cardiovascular function and discusses evidence for how antioxidants both may promote NO bioavailability and counteract adaptations to exercise training.
the International Society of Biomechanics, which will be held in Brisbane in July 2017, will also be provided. The 4 papers in the session were chosen to give a broad crosssection of some of the innovative biomechanics research currently being undertaken in the region. In Paper 1 ultrasound is used to quantify the 3D changes in shape that occur as a function of increasing muscle contraction intensity. Paper 2 uses ultrasound to quantify foot muscle size in young and older adults and has implications for development of toe deformities and reduced balance in older adults. Paper 3 evaluates the use of a markerless motion capture approach for the non-invasive on-field measurement of athletes during match play. Paper 4 focuses on quantifying the clinical relevance of diminished muscle force control in anterior cruciate ligament deficient, anterior cruciate ligament reconstructed and low back pain populations. Following the four papers, a discussion about the future of biomechanics research will be led by the chairs.
http://dx.doi.org/10.1016/j.jsams.2015.12.187
174 Training and testing the top-class soccer player J. Bangsbo The Department of Nutrition, Exercise and Sport, University of Copenhagen, Denmark Match analysis and physiological measurements during match play have revealed that modern soccer is highly demanding, and, hence, soccer players need high fitness levels to cope with the demands of the game. This requires appropriate training as well as testing to evaluate the development of the players. The training activities in football should resemble those experienced during the game, e.g. changes of speed, direction and typical movement patterns, so that the specific muscle groups recruited in football are trained and the coordinative, technical and tactical elements are developed under physical demanding conditions similar to those encountered during actual match-play. Thus, studies of soccer players have shown that speed endurance training and aerobic high-intensity performed as small-sided games have a positive effect on high-intensity intermittent exercise performance as evaluated by Yo-Yo intermittent recovery test. Generally, the type and amount of high-intensity training should be game-related and specific to the individual technical, tactical and physical demands imposed on each single player. http://dx.doi.org/10.1016/j.jsams.2015.12.188
175 Australian and New Zealand Society of Biomechanics (ANZSB) session Introduction: Biomechanics substantially underpins our understanding of how physical performance may be improved and how injuries may be prevented. The aim of this symposium is to showcase some of the current research being undertaken in the field and to stimulate further discussion about future directions for biomechanics research. The session will consist of 4 papers followed by a panel discussion involving past and present executive members of the ANZSB and the International Society of Biomechanics (ISB). Details of the XXVIth Congress of
Paper 1: Three-dimensional muscle bulging and its implications for muscle force generation. Paper 2: Using ultrasound to investigate sarcopenia in foot muscles. Paper 3: A markerless motion capture technique for sport performance analysis and injury prevention: toward a ‘big data’, machine learning future. Paper 4: Clinical implications of muscle force control. http://dx.doi.org/10.1016/j.jsams.2015.12.189
176 Three-dimensional muscle bulging and its implications for muscle force generation G. Lichtwark University of Queensland, Australia Background: Muscle bulging, and particularly changes in thickness in pennate muscles, has been suggested to amplify the velocity of contraction by allowing muscle fibres to rotate without changing length. However, it is not clear what governs such shape changes in muscle or the influences this has on the stretch of elastic connective tissues, such as the aponeurosis. The aim of this investigation was to a) determine the viability and reliability of a novel ultrasound imaging method for exploring how muscles in the human lower limb bulge during contractions and b) examine how muscle bulging and aponeurosis stretching influences muscle fibre dynamics at different muscle lengths. Methods: A three-dimensional ultrasound (3DUS) method was used to characterise the in vivo deformation of the human tibialis anterior (TA) muscle at various contraction intensities of isometric dorsiflexion. Subjects (N = 12) were seated in a reclined position with their left knee extended and left ankle at 90◦ . The 3DUS scan involved synchronous B-mode ultrasound imaging and 3D motion capture of the position and orientation of the transducer, while successive cross-sectional slices were made whilst sweeping a transducer from the proximal to distal end of the TA muscle. We examined the intra-session reliability of the muscle volume and length measurements and determined how the muscle bulged in different dimensions by measuring stretch of the internal aponeurosis in both the longitudinal and transverse directions. Results: The 3DUS technique was shown to be highly reliable across measures of muscle volume, muscle length, fascicle length and central aponeurosis length at all contraction intensities (intrasession ICC > 0.99 and CV < 2% for all measures). The TA muscle
Friday 23 October Papers / Journal of Science and Medicine in Sport 19S (2015) e57–e87
harmful compound peroxynitrite. In addition, high levels of ROS can lead to an alteration (uncoupling) of nitric oxide synthase, whereby the enzyme produces ROS instead of NO. Evidence for an interaction between NO and ROS has been provided in studies on aged individuals who are believed to have elevated levels of ROS in the vascular system. Such studies show that infusion of antioxidants into the blood can improve the level and function of NO. On the other hand ROS have been shown to be important signaling molecules for adaptations in response to exercise training. There is substantial evidence for that intake of antioxidants in connection with endurance training can attenuate and even abolish cardiovascular adaptations in response to training. This lecture focuses on the role of NO and ROS for cardiovascular function and discusses evidence for how antioxidants both may promote NO bioavailability and counteract adaptations to exercise training.
the International Society of Biomechanics, which will be held in Brisbane in July 2017, will also be provided. The 4 papers in the session were chosen to give a broad crosssection of some of the innovative biomechanics research currently being undertaken in the region. In Paper 1 ultrasound is used to quantify the 3D changes in shape that occur as a function of increasing muscle contraction intensity. Paper 2 uses ultrasound to quantify foot muscle size in young and older adults and has implications for development of toe deformities and reduced balance in older adults. Paper 3 evaluates the use of a markerless motion capture approach for the non-invasive on-field measurement of athletes during match play. Paper 4 focuses on quantifying the clinical relevance of diminished muscle force control in anterior cruciate ligament deficient, anterior cruciate ligament reconstructed and low back pain populations. Following the four papers, a discussion about the future of biomechanics research will be led by the chairs.
http://dx.doi.org/10.1016/j.jsams.2015.12.187
174 Training and testing the top-class soccer player J. Bangsbo The Department of Nutrition, Exercise and Sport, University of Copenhagen, Denmark Match analysis and physiological measurements during match play have revealed that modern soccer is highly demanding, and, hence, soccer players need high fitness levels to cope with the demands of the game. This requires appropriate training as well as testing to evaluate the development of the players. The training activities in football should resemble those experienced during the game, e.g. changes of speed, direction and typical movement patterns, so that the specific muscle groups recruited in football are trained and the coordinative, technical and tactical elements are developed under physical demanding conditions similar to those encountered during actual match-play. Thus, studies of soccer players have shown that speed endurance training and aerobic high-intensity performed as small-sided games have a positive effect on high-intensity intermittent exercise performance as evaluated by Yo-Yo intermittent recovery test. Generally, the type and amount of high-intensity training should be game-related and specific to the individual technical, tactical and physical demands imposed on each single player. http://dx.doi.org/10.1016/j.jsams.2015.12.188
175 Australian and New Zealand Society of Biomechanics (ANZSB) session Introduction: Biomechanics substantially underpins our understanding of how physical performance may be improved and how injuries may be prevented. The aim of this symposium is to showcase some of the current research being undertaken in the field and to stimulate further discussion about future directions for biomechanics research. The session will consist of 4 papers followed by a panel discussion involving past and present executive members of the ANZSB and the International Society of Biomechanics (ISB). Details of the XXVIth Congress of
Paper 1: Three-dimensional muscle bulging and its implications for muscle force generation. Paper 2: Using ultrasound to investigate sarcopenia in foot muscles. Paper 3: A markerless motion capture technique for sport performance analysis and injury prevention: toward a ‘big data’, machine learning future. Paper 4: Clinical implications of muscle force control. http://dx.doi.org/10.1016/j.jsams.2015.12.189
176 Three-dimensional muscle bulging and its implications for muscle force generation G. Lichtwark University of Queensland, Australia Background: Muscle bulging, and particularly changes in thickness in pennate muscles, has been suggested to amplify the velocity of contraction by allowing muscle fibres to rotate without changing length. However, it is not clear what governs such shape changes in muscle or the influences this has on the stretch of elastic connective tissues, such as the aponeurosis. The aim of this investigation was to a) determine the viability and reliability of a novel ultrasound imaging method for exploring how muscles in the human lower limb bulge during contractions and b) examine how muscle bulging and aponeurosis stretching influences muscle fibre dynamics at different muscle lengths. Methods: A three-dimensional ultrasound (3DUS) method was used to characterise the in vivo deformation of the human tibialis anterior (TA) muscle at various contraction intensities of isometric dorsiflexion. Subjects (N = 12) were seated in a reclined position with their left knee extended and left ankle at 90◦ . The 3DUS scan involved synchronous B-mode ultrasound imaging and 3D motion capture of the position and orientation of the transducer, while successive cross-sectional slices were made whilst sweeping a transducer from the proximal to distal end of the TA muscle. We examined the intra-session reliability of the muscle volume and length measurements and determined how the muscle bulged in different dimensions by measuring stretch of the internal aponeurosis in both the longitudinal and transverse directions. Results: The 3DUS technique was shown to be highly reliable across measures of muscle volume, muscle length, fascicle length and central aponeurosis length at all contraction intensities (intrasession ICC > 0.99 and CV < 2% for all measures). The TA muscle