The purpose of this investigation was to examine the contractile properties of individual slow and fast myofibers in response to various training periods throughout a collegiate cross-country season in male runners. Muscle biopsies were obtained from the gastrocnemius of five runners at three time points during the season; after a summer aerobic training phase (T1); after an 8 week period of intense training (T2) and after a 4 week taper period (T3). Absolute (4.6±0.3 L/min) and relative (71±0.7 mI/kg/min) maximal oxygen consumption were unchanged during the study duration. Run performance (8 km) improved 3% from T1 to T2 (27:26 to 26:38 min:sec) and 1% from T2 to T3 (26:21 min:sec). A total of 328 individual myofibers were isolated and studied at 15°C. MHC I diameter was 3% lower (P < 0.05) at T2 compared to T1 and 4% smaller at T3 compared to T2. MHC I and Ila fibers were 18 and 11 % stronger (P < 0.05) respectively, from T1 to T2. MHC I fibers produced 9% less force (P < 0.05) after the taper (T2-T3) while MHC Ila fibers were 9% stronger (P < 0.05). Specific tension (Po/CSA) increased (P < 0.05) 38 and 26% for MHC I and Ila fibers, respectively from T1 to T2 and was unchanged with the taper. Maximal shortening velocity (Vo) of the MHC I fibers decreased (P < 0.05) 23% from T1 to T2 and 17% from T2 to T3. MHC I peak power decreased (P < 0.05) 20% from T1 to T2 and 25% from T2 to T3. Power corrected for cell size decreased (P < 0.05) 15% from T2 to T3 and was 24% lower at T3 compared to T1 for the MHC I fibers only. MHC Ila diameter, Vo, peak and normalized power were unaltered during the study duration. These data suggest that myocellular function is sensitive to changes in run training and it appears that MHC I fibers are moreaffected than MHC IIa fibers. Furthermore, the increase in interval training with the taper may have offset the modest reduction in training volume and prevented any positive adaptations at the cellular level. / Human Performance Laboratory

Access to abstract permanently restricted to Ball State community only / Access to thesis permanently restricted to Ball State community only / School of Physical Education, Sport, and Exercise Science

Thesis (M.S.)--University of Hawaii at Manoa, 2007. / Includes bibliographical references (leaves 35-36). / ix, 36 leaves, bound ill. 29 cm

Thesis PlanA (M.S.)--University of Wisconsin--Stout, 2009. / Includes bibliographical references.

Thesis (M.S.)--California Polytechnic State University, 2010. / Mode of access: Internet. Title from PDF title page; viewed on April 1, 2010. Major professor: Ann Yelmokas McDermott, Ph.D., M.S., LDN. "Presented to the faculty of California Polytechnic State University, San Luis Obispo." "In partial fulfillment of the requirements for the degree of Master of Science in Kinesiology." "March, 2010." Includes bibliographical references (p. 49-54).

Thesis (M.S.)--Springfield College, 2004. / Includes bibliographical references. Also available online (PDF file) by a subscription to the set or by purchasing the individual file.

Thesis (M.S.)--Brigham Young University. Dept. of Exercise Sciences, 2005. / Includes bibliographical references.

Thesis (M.S.)--Florida State University, 2006. / Advisor: Emily M. Haymes, Florida State University, College of Human Sciences, Dept. of Nutrition, Food and Exercise Science. Title and description from dissertation home page (viewed Sept. 15, 2006). Document formatted into pages; contains x, 181pages. Includes bibliographical references.

Thesis (M.S.)--Springfield College, 2004. / Includes bibliographical references.

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.