http://hdl.handle.net/2436/22519 Thu, 20 Jun 2013 02:59:33 GMT 2013-06-20T02:59:33Z http://hdl.handle.net/2436/106660 Title: Biological evidence for the acute health effects of secondhand smoke exposure Authors: Flouris, Andreas D.; Vardavas, Constantine I.; Metsios, Giorgos S.; Tsatsakis, A. M.; Koutedakis, Yiannis Abstract: A vast number of studies on the unfavorable effects of secondhand smoke (SHS) exist within the international literature, the majority of which evaluate longitudinal epidemiological data. Although limited, the experimental studies that assess the acute and short-term effects of exposure to SHS are also increasing in number. They include cellular, animal, and human studies that indicate a number of pathophysiological mechanisms through which the deleterious effects of SHS may arise. This current review evaluates the existing biological evidence regarding the acute health effects of SHS exposure. Analyses on the inhaled toxicants and the carcinogenicity of SHS are included as well as in-depth discussions on the evidence for acute SHS-induced respiratory, cardiovascular, metabolic, endocrine and immune effects, and SHS-induced influences on oxygen delivery and exercise. The influence of the length of exposure and the duration of the observed effects is also described. Moreover, recent findings regarding the underlying pathophysiological mechanisms related to SHS are depicted so as to generate models that describe the SHS-induced effects on different systems within the human body. Based on the presented biological evidence, it is concluded that brief, acute, transient exposures to SHS may cause significant adverse effects on several systems of the human body and represent a significant and acute health hazard. Future research directions in this area include research on the concentrations of tobacco smoke constituents in the alveolar milieu following SHS exposure, individual susceptibility to SHS, as well as the effects of SHS on neurobehavioral activity, brain cell development, synaptic development, and function. Fri, 01 Jan 2010 00:00:00 GMT http://hdl.handle.net/2436/106660 2010-01-01T00:00:00Z http://hdl.handle.net/2436/106657 Title: Body composition and ballet injuries: a preliminary study Authors: Twitchett, Emily; Angioi, Manuela; Metsios, Giorgos S.; Koutedakis, Yiannis; Wyon, Matthew Abstract: To date, the effects of body composition on injury occurrence and healing times in dancers have received limited scientific attention. The aim of the current study was to determine possible associations between somatotype, percent body fat, and self-reported injury characteristics in dance students. Forty-two full-time ballet students (11 male, 31 female) from two vocational dance schools volunteered for the study. The Heath-Carter protocol and Siri equation were adopted to calculate somatotype and percent body fat (%BF), respectively. Injury types, together with the time taken to recover from injury, were assessed using a recall injury questionnaire. Results revealed that the sample was classified as balanced-mesomorph somatotype (endomorphy – mesomorphy – ectomorphy = 3.4±0.9 – 3.9±1.4 – 3.2±1.2). Ectomorphy was a strong predictor of the number of acute injuries sustained (F1,36 = 5.4, p = 0.026); these parameters also revealed a significant negative correlation (r = –0.37, p = 0.016). Significant negative correlations were observed between the dancers’ total time off due to injury and %BF (r = –0.31, p = 0.048) and between the total time off resulting from acute injury and both %BF (r = –0.32, p = 0.04) and ectomorphy (r = –0.42, p = 0.005). The number of overuse injuries sustained and time off due to overuse injury also were correlated with mesomorphy (r = –0.38, p = 0.015 and r = –0.33, p = 0.032, respectively). It was concluded that high ectomorphy ratings, low %BF values, and low mesomorphy ratings are linked to injury. More relevant research is required on dancers from different genres. Tue, 01 Jan 2008 00:00:00 GMT http://hdl.handle.net/2436/106657 2008-01-01T00:00:00Z http://hdl.handle.net/2436/106645 Title: Muscular strength: applications for dancers Authors: Koutedakis, Yiannis; Clarke, Frances; Wyon, Matthew; Aways, Danielle; Owolabi, Emmanuel O. Abstract: Muscle fibers can generally be divided into slow and fast twitch according to their contraction speed. Even though an individual normally has the same ratio of slow/fast muscle fibers throughout his or her body, the lower-limb muscles are predominantly designed to provide the maximum dynamic output in rapid movements (e.g., jumping). The limited data on dancers’ muscle profiles have shown that (ballet) dancers have predominately slow fibers. Muscular strength, together with aerobic and anaerobic capacity, joint mobility and muscle flexibility, and body composition form the continuum of physical fitness. Strength is defined as the maximum force that a muscle group can generate at a specified velocity; its levels can be affected by several factors. which include age, gender, type of muscle fiber, nutrition, and body temperature. There is no scientific evidence suggesting that different strength training regimens should be employed for the different styles of dance. However, reduced muscular strength has been associated with greater severity of injury in dancers. Poor aerobic capabilities, high ectomorphy ratings with low percent body fat values, and the biomechanics of different dance techniques have also been identified as underlying sources of injury in dancers. The most common location for injury in ballet dancers is the foot and the ankle, while in contemporary dancers it is the low back and knee. Little information is available with respect to other dance styles. Thu, 01 Jan 2009 00:00:00 GMT http://hdl.handle.net/2436/106645 2009-01-01T00:00:00Z http://hdl.handle.net/2436/106653 Title: Physiological fitness and professional classical ballet performance : a brief view Authors: Twitchett, Emily; Koutedakis, Yiannis; Wyon, Matthew A. Abstract: Although classical ballet is an artistic expression through the use of the body, there is a real opportunity to improve and extend the dancer’s career by simply applying sports science principles to dance training and performance. Dance training is a long process of physical, intellectual, and psychological preparation, through physical exercise, often beginning in childhood and continuing until retirement. Fitness programs, supplementary to traditional dance classes, have only recently been considered as a part of this process; it may be suggested that this cross-training has generally been avoided thus far because of tradition and a reluctance to follow principles associated with sport. Classical ballet training, rehearsal, and performance do not elicit significant stimulus to result in increased aerobic fitness levels. Therefore, dancers often demonstrate low levels of aerobic fitness even though a strong aerobic foundation is necessary to meet the required workload. Dancers have greater than average range of motion and strength at the hip joint but weaknesses in the upper body, torso, hamstrings, and quadriceps. In the past, dancers have been wary of strength training because they perceive this leads to aesthetically undesirable hypertrophy. Dancers also have low body weights and low percentage body fat. Given that training does not provide the opportunity to expend enough energy to maintain these aesthetic demands, this aesthetic demand may be met by caloric restriction, which may lead to subsequent increased injury risk. It has been hypothesized that a ‘‘fit for purpose’’ body can help improve performance, reduce the risk of injury, and ensure prolonged dance careers. This review aims to explore the extent to which physical fitness components relate to dance performance, in particular classical ballet. Thu, 01 Jan 2009 00:00:00 GMT http://hdl.handle.net/2436/106653 2009-01-01T00:00:00Z