The purpose of this study was to examine the effects of different surfaces on lower limb motion and encountered pressures at two locations on the plantar surface of the right foot. Nine females performed five trials for each of four surface conditions. The results provided no evidence for surface-related changes in experienced foot contact pressures. Both asphalt and grass surfaces resulted in the shortest relative time of forefoot immobility. No surface related differences were found for the range of pronation.

Zetisky Jonathan V 9213052F zeds@telkomsa.net Master of Science in Medicine Faculty of Health Sciences M.Sc (med) Prof Rogers, G / Development in triathlon at the elite level can be improved by knowing the physical, physiological and anthropometrical characteristics of current elite triathletes and single sport athletes, and isolating those factors that contribute to high levels of performance. Much research on this topic has been done with regard to the single sport disciplines of running, swimming and cycling. However, less is known about triathletes. The primary purpose of this study was therefore to see whether and how triathletes differ from the single sport athletes in the disciplines of swimming, cycling and running, and by so doing, to develop a profile of an elite South African triathlete. Thirty-four subjects (triathletes: n = 12; runners: n = 8; swimmers: n = 6 and cyclists: n = 8) were measured for the physical characteristics of age, mass, height, body fat and lean body mass. Anthropometric measurements (skinfolds, bone breadths and girths) were also taken along with the physiological components of VO2 maximum (maximal oxygen consumption) and running economy. Muscle strength and endurance were also measured. The results showed that triathletes do not differ significantly from the single sport athletes (swimmers, cyclists and runners) in any of the components measured. In fact, they are generally most similar to cyclists in all of the categories measured and in each of these, lie between runners and swimmers. Runners and swimmers however, were significantly different (P<0.05) from each other in terms of mass (kg), lean body mass (kg) and maximal oxygen consumption (ml O2/kg.min-1). 3 No significant differences were noted between the triathletes, swimmers, cyclists and runners in endomorphy, mesomorphy and ectomorphy somatotype ratings. Swimmers (2 – 3,9 – 2,7) and cyclists (2 – 4 – 2,8) as well as the triathletes (2 – 3,8 – 2,8) fall into the ectomorphic-mesomorph somatotype while runners (1,8 – 3 – 3,5) on the other hand, were classified as mesomorphic-ectomorph. The study therefore suggests that no single physical, physiological or anthropometrical factor determines successful performance. Rather, it is a blend of physical and physiological traits observed in the single sport athletes that makes a successful triathlete.

O pedestrianismo vem se tornando cada vez mais expressivo na atualidade, principalmente por assegurar condições de bem-estar físico, psicológico e social ao praticante. Partindo-se do pressuposto que deficiências nutricionais prejudicam o desempenho durante a corrida, corredores de longa duração vêm usufruindo da suplementação esportiva com o intuito de otimizar o rendimento. Todavia, faltam evidências científicas quanto aos recursos ergogênicos proporcionados pelos diversos suplementos alimentares comercializados. Sendo assim, o objetivo desta pesquisa foi comparar o desempenho de corredores de longa duração em um protocolo de exercício físico em esteira composto por três situações diferentes de suplementação: placebo, carboidrato e carboidrato associado à proteína hidrolisada. A amostra foi composta por 14 atletas do sexo masculino e o estudo apresentou design cross over com caráter duplo-cego. Inicialmente, foi realizada avaliação cardiorrespiratória e nutricional, sendo que esta última foi composta por antropometria (peso e estatura) e composição corporal (dobras cutâneas). Os indivíduos foram submetidos a um exercício físico em esteira constituído por 60 minutos com velocidade e inclinação correspondente ao Limiar Anaeróbio e posteriormente perduraram a atividade até a exaustão com intensidade 10% acima desta variável. Foi analisado o consumo alimentar por meio drae feinrgeenstetã ao energética diária e da quantidade de macronutrientes ingeridos nas 24 e 2 horas antecedentes aos exercícios. Mensurou-se a glicemia, o lactato sanguíneo, a percepção subjetiva de esforço e a frequência cardíaca durante os três protocolos de suplementação. A glicemia inicial e 5 minutos após a exaustão foi menor para o grupo placebo quando comparada aos outros dois grupos. Houve um aumento na glicemia e no lactato nos três grupos ao comparar momentos antes e durante o exercício (60 minutos) com momentos após o término da atividade (exaustão e 5 minutos após este estágio). Observou-se aumento na percepção subjetiva de esforço e na frequência cardíaca nos três grupos concomitantemente ao aumento da duração e/ou intensidade do exercício. Ao analisar o consumo alimentar e o tempo de exaustão dos atletas não foram constatadas diferenças estatísticas entre os três suplementos utilizados. Diante disto, analisando agudamente, não há justificativa para adicionar proteína ao suplemento de carboidrato durante a realização de exercícios de endurance com características semelhantes ao de nosso estudo. / The pedestrianism is becoming increasingly significant nowadays, mainly for ensuring conditions of physical, psychological and social well-being practitioner. Starting from the assumption that nutritional deficiencies impair performance during the race, long runners come enjoying the sports supplementation in order to optimize performance. However, they lack scientific evidence about the ergogenic resources provided by the various food supplements marketed. Thus, the aim of this study was to compare the performance of long runners in a physical exercise protocol on a treadmill consists of three different situations supplementation: placebo, carbohydrate and carbohydrate associated with hydrolyzed protein. The sample consisted of 14 male athletes and this study was double-blind with crossover design. Initially, individual performed cardiopulmonary and nutritional evaluation and the latter consisted of anthropometry (weight and height) and body composition (skinfold). The subjects underwent a physical exercise on a treadmill consists of 60 minutes with speed and inclination corresponding to Anaerobic Threshold and then endured the activity to exhaustion intensity with respect to 10% higher this variable. Food consumption through daily energy intake and the amount of macronutrients ingested in 24 and 02 hours before the exercise was analyzed. blood glucose, blood lactate, the perceived exertion and heart rat eI td wurainsg m theea stuhrreede supplementary protocols. The initial blood glucose and 5 minutes after the exhaustion was lower in the placebo group compared to the other two groups. There was an increase in blood glucose and lactate in the three groups when comparing time before and during exercise (60 minutes) with moments after the end of the activity (exhaustion and 5 minutes after this stage). There was an increase in perceived exertion and heart rate in the three groups concomitantly with increasing duration and/or intensity of exercise. By analyzing the food consumption and time to exhaustion of athletes were not found statistical differences between the three supplements used. Given this, there would be no acute justification for adding protein to carbohydrate supplement when performing endurance exercise with characteristics similar to our study.

No description available.

Based on Self-Determination Theory (e.g., Deci & Ryan, 1985a, 2000; Ryan & Deci, 2002) this research focused on the motivation of ten elite Ethiopian male and female long distance runners. The semi-structured interview guide based on the SDT was transcribed verbatim and subjected to an inductive-deductive analysis approach based on the methodological guidance provided by Maykut & Morehouse (1994). Results revealed the integrated type of motivation to be the most evident among the runners. The data were organized into three broad categories that emerged through the interviews. The three categories are nationalism, economics and fame. Within each category there are themes or subcategories that emerged across various perceptions of the Ethiopian runners. The data revealed that among different types of motivation classified by the Self-Determination Theory (e.g., Deci & Ryan, 1985a, 2000; Ryan & Deci, 2002) there are multiple social factors that influence Ethiopian runners as well.

Introduction: The benefits of regular exercise on skeletal health have been well-documented in terms of stimulation of bone accrual and bone maintenance. Medium-impact sports activities such as running have been demonstrated to exert site-specific enhancement of bone mass in the lower appendicular skeleton. However, elite female runners engaged in high intensity training and sports activity may also be at risk of amenorrhea and low bone mineral density (BMD) resulting from inadequate caloric intake. Purpose: To investigate the effect of intensive exercise and maintenance of adequate caloric intake on BMD in a group of elite female runners. Methods: This study represents a secondary assessment of existing data that were obtained between 1994 and 2009. Using dual-energy X-ray absorptiometry, a group of elite runners (n=11) in this study was screened in the Laboratory for Elite Athlete Performance at Georgia State University. This was a longitudinal study in which three sequential measurements of BMD, as well as fat and lean tissue body composition of each athlete took place. The average interval between measurements was 1.1 years and 2.6 years respectively. Regional BMD measurements for head, arms, legs, trunk, ribs, pelvis, and spine were assessed, as well as the value for total body BMD. The study participants also received dietary counseling emphasizing daily caloric balance and adequate calcium intake. Results: The average age of the runners increased from 24.59 (±4.41) to 28.14 (±5.94) years over the study. This was accompanied by an increase in body mass (54.98±3.54 to 56.11±4.07 kg), while height remained constant. The average body mass index (BMI) of the subjects increased from 19.34 to 19.71 kg/m2, largely due to an increase in total per cent body fat (13.97±2.96% to 16.01±4.28%). Average regional and total BMD values increased over the study period and increases were between 2 and 4%. A majority of subjects (n=7) had a BMI>19 kg/m2, while a sub-group of runners (n=4) had a BMI˂19 kg/m2. Mean trunk, pelvis and spine BMD parameters for the two BMI groups were significantly different (p˂0.05), with reduced BMD values in the lower BMI sub-group. The average T-scores associated with arm BMD were considerably lower than T-scores associated with leg BMD values in the runners. The average T-scores for leg BMD values were almost two standard deviations higher than leg BMD values for a reference population at peak bone mass. Two subjects were osteopenic, resulting in an 18% prevalence rate of osteopenia in the group of runners. Conclusions: The majority of elite runners in this study exhibited a positive trend in BMD parameters. This was reflected as increased total as well as regional BMD values. Increased body mass in addition to the activity of running positively contributed to bone mass via a weight-bearing effect. Increased adipose tissue may also have been a source of endocrine hormones such as estrogen and leptin, which exert a positive effect on bone accrual.

Thesis (M.A.)--University of Alabama at Birmingham, 2009. / Title from PDF title page (viewed Jan. 28, 2010). Includes bibliographical references (p. 23-24).

No description available.

A comparison of heart rate viability and respiratory sinus arrhythmia (RSA) characteristics was performed in 20 athletes and 12 age-matched sedentary controls (CTRL) (22 +/- 2.4 yrs). More specifically, this study examined the role of regular physical activity on the breathing frequency (BF)---RSA amplitude response curve comparing varsity swimmers (SW) to endurance runners (RU) to test the hypothesis that a locomotor-respiratory entrainment resulting from the water-immersion breathing pattern of swimmers would alter their respiratory related cardiac vagal integrative response. Spectral power components of HRV were computed from R-R interval sequences. Five-minute recordings were performed with subjects breathing either at their spontaneous breathing rate, at four breathing cycles less (M4) and four cycles more (P4) than spontaneous. Amplitude and phase of RSA were computed from the sinusoid fitted to the instantaneous heart rate within each breath while the gain of the RSA response was obtained from the slope of the RSA amplitude versus BF. (Abstract shortened by UMI.)

One major way that running style varies between individuals is how their foot strikes the ground (forefoot strike or rearfoot strike). Running generates a torque about the ankle that depends on the individual’s foot strike pattern, length of their plantar flexor moment arm, and force generated from the plantar flexor muscles. The foot strike pattern during running, gastrocnemii muscle thickness, and heel length (used as an approximation for plantar flexor moment arm) were determined in 41 runners. Forefoot and rearfoot strike runners had the same thickness of the gastrocnemii muscles. However, in comparison with sedentary walkers, the runners had thicker calf muscles. These results imply a “peak” muscle thickness seems to be attained by running. Runners with longer heels were more likely to use a forefoot strike running style, possibly due to a mechanical advantage in the generation of torque.