صفحه 36 | ورزش Patients who are unable to use their Meanwhile, another group also muscles for extended periods of time - underwent 4 weeks of immobilization, such as those who have suffered a but they performed mental imagery of stroke - often experience weakened strong muscle contractions 5 days per muscles from lack of use. But now, a week. new study suggests that performing In addition, a control group mental imagery exercises can prevent underwent no interventions. Medical the unused muscles from getting News Today did not have access to the weaker. number of total subjects who participated in the study. Before, The researchers, from the Ohio immediately after and 1 week following University Heritage College of the immobilization interventions, the Osteopathic Medicine, publish their researchers measured wrist flexor findings in the Journal of strength. Neurophysiology. As the first group imagined Using mental imagery for physical contracting their muscles and flexing performance is not necessarily a new their wrist, the researchers recorded concept; professional athletes often their muscle activity using an use such techniques to improve their electromyogram (EMG). athletic performance. However, the Overall, the results showed that the team says theirs is the first study to mental imagery training attenuated the demonstrate that imagery can stop or loss of strength. Explaining their slow muscle strength loss after long findings further, Prof. Clark says: periods of disuse. "What our study suggests is that The findings have implications for imagery exercises could be a valuable individuals undergoing tool to prevent or slow muscles from neurorehabilitation and provide a becoming weaker when a health "major breakthrough" for scientists, in problem limits or restricts a person's that they offer new evidence about how mobility. the nervous system affects muscle The most impactful finding, weakness. however, is not the direct clinical Though medical scientists have application, but the support that this known that the brain's cortex work provides for us to better coordinates and controls muscle understand the critical importance of movement, until now, the link between the brain in regulating muscle strength. the cortex and muscle strength has This information may fundamentally been up for debate. change how we think about muscle Prof. Brian Clark, study author and weakness in the elderly." director of the Ohio Musculoskeletal The researchers further say that and Neurological Institute refers to their findings suggest neurological muscles as the nervous system's mechanisms at the cortical level puppets, with the brain acting as the contribute to "disuse-induced string prompting the muscles to move. weakness," adding that imagery Findings unveil 'importance of brain activating the cortical regions lessens in regulating muscle strength' weakness "by maintaining normal To conduct their study, the team had levels of inhibition." a group of healthy individuals undergo In October of this year, researchers 4 weeks of wrist-hand immobilization reported the development of a new - achieved by wearing a cast - to prosthetic arm that is controlled by the encourage muscle weakness. brain. Page 12 | Sport Can mental exercise prevent unused muscles from getting weaker? صفحه 37 | ورزش صفحه 38 | ورزش HAT-TRICK A hat-trick or hat trick in sports is the achievement of a positive feat three times or more during a game, or other achievements based on threes. The term was first used in 1858 in cricket to describe HH Stephenson's feat of taking three wickets with three consecutive deliveries. A collection was held for Stephenson, and he was presented with a hat bought with the proceeds. The term was used in print for the first time in 1878. The term was eventually adopted by many other sports including football (soccer), water polo, and team handball, but did not become popular in North America until the mid-1940s in the National Hockey League. Qualifications As is the case in many sports, there are some informal rules regarding the use of the term "hat trick" in soccer. For example, if the match is tied after extra time and goes to a penalty-kick shootout, any goals scored do not count toward a hat trick. Thus, a hat trick in soccer can occur only during regulation time, added time and extra time. Any goals scored on penalty kicks before a shootout would count toward a hat trick. Thomas Muller hit the 49th hat-trick in World Cup history during Germany's 4-0 victory over Portugal in Salvador. Page 10 | Sport Hat trick Hat-trick: Three goals scored by a player in a single match. The player will often be given the match ball after scoring a hat-trick. صفحه 39 | ورزش صفحه 40 | ورزش Too much sport may be bad for teens' health Low sports activity was found in 35% of subjects, Commenting on their findings, the researchers 41.5% had average activity, 18.5% had high, while 5% say: had very high. "Physical activity has been associated with Very high activity 'just as bad' as low activity positive emotional well-being, reduced depressive, The investigators found that participants in the anxiety and stress disorders, and improved self- low and very high activity groups were more than esteem and cognitive functioning in children and twice as likely to have well-being scores below 13, adolescents. compared with subjects in the average group. We found that sports practice apparently ceased The researchers say this corresponds to an to be a protective factor and became an independent "inverted U shaped" link between weekly duration risk factor for poor well-being when practicing more of sports practice and well-being. than twice the 7 recommended hours per week." They also found that the highest well-being scores The investigators note that their study highlights were obtained by participants who carried out the importance for physicians caring for adolescents around 14 hours of physical activity a week, but to monitor their level of sports practice and ask them beyond 14 hours resulted in lower well-being scores. about their well-being. Page 8 | Sport Too much sport may be bad for teens' health Teenagers have long been told that being active and taking part in sports is good for their health. But new research suggests that too much sport for teenagers could negatively impact their well-being just as much as too little sport. The US Department of Health and Human Services regarding demographics, height and weight, recommends that young people aged between 6 and socioeconomic status, sports practice, sports injuries 17 years carry out at least 60 minutes of physical and well-being. activity a day, equating to 7 hours a week. Their well-being was assessed using the World But researchers from Switzerland and Canada say Health Organization (WHO) Well-Being Index, which their study, published in the BMJ journal Archives of provides scores between 0 and 25. A score below 13 Disease in Childhood, suggests that 14 hours of is an indicator of poor well-being. physical activity a week is best for promoting good Of the participants, 50.4% were male with a mean health in teenagers. However, they found that more age of 17.95 years. Almost 9% of these males were than 14 hours appears to be detrimental to their overweight or obese. The overall average well-being health. score for all participants was 17. To reach their findings, the investigators surveyed The researchers categorized sports participation more than 1,245 teenagers aged between 16 and 20 as low (0-3.5 hours a week), average (3.6-10.5 hours), from Switzerland. high (10.6-17.5 hours), and very high (more than 17.5 | .(were required to answer questions hours صفحه All 41 participantsورزش The SportAccord is deeply rooted in the sports sport for sport” allows IFs and sports business to get movement. As early as 1921, international sports together, share knowledge and network. federations (IFs) expressed the need for a In March 2009, GAISF was rebranded SportAccord representative of their common objectives and and, in the same year, its offices moved to Lausanne, interests. Under the direction of Paul Rousseau, the Olympic Capital. SportAccord officially adopted Secretary General of the Union Cycliste Internationale the mission to UNITE & SUPPORT and developed into (UCI), a permanent bureau of the IFs was established a dynamic and active organization which aims to to facilitate the dialogue with the Olympic authorities. serve and promote its members. Its ambition is to In 1967, 26 international sports federations met provide high-quality services and expertise in areas in Lausanne and agreed on the need to increase that are of high importance to its members. permanent liaisons and the name “General Assembly Currently, SportAccord’s focus is on sports’ social of International Sports Federations” was adopted. In responsibility, sports’ integrity, doping-free sport, order to establish a more formalized organization, digital media and multi-sports games. the “General Association of International Sports On May 25, 2012, the last of eight days of the Federations" (GAISF) was formed in 1976 and the annual General Assembly of SportAccord in Quebec headquarters were moved to Monaco two years City, the Federation of International Lacrosse and the later. International Mind Sports Association were accepted, The new millennium brought important changes bringing "the number of SportAccord members to to the organization. Reacting to the increasing 107". pressure on IFs to professionalize and develop, GAISF On May 31, 2013, the last of eight days of the in collaboration with the Associations of Summer and annual General Assembly of SportAccord in Saint Winter Olympic International Federations (ASOIF Petersburg, the International Cheer Union and the and AIOWF), launched first SportAccord International Federation Internationale de I'Automobile were Convention in 2003. At the time, this new format “by voted into SportAccord.