Background: Due to the unique demands of the sport, athletes playing football perform a variety of differing training methods to improve physiological performance. These include strength, endurance and sprint training. While the effects of strength and endurance training have been well researched, the effects of repeated-sprint training on blood and muscle variables in well trained males and females are not well known. An understanding of changes to the blood and muscle during and following an exercise bout are important, so to gain an understanding of the type of stress and resulting adaptations that may occur. Also, while a large volume of research in training adaptations has been performed on males; little has been done on females. To date, some research indicates metabolism during moderateintensity exercise may differ between males and females; however, no study has compared repeated-sprint exercise. Therefore, it is unclear as to whether males and females would have a differing physiological response to repeated-sprint training. Purpose: The purpose of this study was to determine the effects of a repeated-sprint bout on molecular signalling in muscle and blood measures and heart rate in well-trained footballers. Additionally, we compared running times and sprint decrement (%). Research Design: Eight female senior University football players (Mean ± SD, age, 19 ± 1 y, VO ? 2peak 53.0 ± 5.1 ml·kg-1min-1) and seven male senior University football players (Mean ± SD, age, 19 ± 3 y, VO ? 2peak 59.0 ± 6.6 ml·kg-1min-1) volunteered to participate in this study. Participants performed four bouts of 6 x 30 m maximal sprints spread equally over a 40 min period. Sprint time was measured (at 30 m) for each sprint and sprint decrement was also calculated for all bouts. Muscle biopsies were taken from the vastus lateralis muscle at rest, 15 min following exercise and 2 h into recovery. Venous blood samples were taken at the same time points as the biopsies while capillary blood lactate was measured at rest and 3 min following each sprint bout. Repeated measures ANOVA and Post hoc t-tests were performed to determine significant differences between the two groups (male vs. female) and time points. Findings: Both groups had a significant (P<0.05) increase in blood lactate (mM) after the first bout of repeated sprints, with no differences between females (pre 0.9 ± 0.4 mM – post 10.0 ± 1.6 mM) and males (pre 0.8 ± 0.3 mM – post 10.0 ± 3.5 mM). Blood lactate remained elevated compared to rest (P<0.05) following bouts 2, 3 and 4 for both females (12.0 ± 3.6, 12.0 ± 3.3, 12.2 ± 3.8 mM respectively) and males (11.9 ± 2.9, 11.6 ± 2.3, 11.5 ± 4.0 mM respectively), with no differences between groups or time points (P>0.05). There were no differences (P>0.05) between the female and male athletes in mean heart rate attained at the end of each bout of repeated sprints (187 ± 2 v 190 ± 2 bpm respectively) or during recovery between sprints (140 ± 2 v 130 ± 2 bpm respectively). There were no differences between groups or time points in blood insulin (P>0.05). Fastest 30 m sprint time and mean 30 m sprint time during the repeated-sprint bout was faster for the males than females (4.58 ± 0.12 v 5.26 ± 0.27 s respectively; (P>0.05)). However, there were no differences in running velocity during the sprints between the males and females (165 ± 0.4 % vs. 155 ± 0.05 %; P>0.05) when expressed relative to velocity at VO ? 2peak (vVO ? 2peak). Also, mean % decrement during the repeated-sprint bout was lower in the males then females (4.9 ± 1.3 v 7.1 ± 1.9 % respectively; P<0.05). No changes were observed in total or phosphorylated Akt at any time-point or between genders. However, while total 4E-BP1 was lower, the ratio of total to phosphoryalated 4E-BP1 at rest was greater in males than females (P<0.05). Finally, there was also a significant decrease in 4E-BP1 phosphorylation post-exercise in males (P<0.05), but not females. Conclusions: There were no sex differences in blood lactate or heart rate throughout the repeated-sprint bout. These findings suggest that there were no cardio respiratory or lactate production/clearance differences in the response to a repeated-sprint-training bout between sexes. However, while males were faster than their female counterparts, the average relative speed was similar between sexes, suggesting a similar relative volume of work was performed during the sprint bouts. However, the females did have a greater decrement in sprint performance indicating a greater ability to recover sprint performance in the males. Sex differences in resting total and phosphorylated 4E-BP1 may indicate greater potential for muscle growth in the male athletes during basal conditions. However, differences could be due to factors other than sex, including previous training history. There was a lack of change in plasma insulin or Akt, but, similar to resistance exercise, a significant decrease in post-exercise 4E-BP1 phosphorylation for the males, but not females. The sex differences in the 4E-BP1 phosphorylation response post-exercise could be due to differences in the metabolic disturbance in the muscle during and following maximal sprints. Keywords: blood lactate, heart rate, muscle

Background: Due to the unique demands of the sport, athletes playing football perform a variety of differing training methods to improve physiological performance. These include strength, endurance and sprint training. While the effects of strength and endurance training have been well researched, the effects of repeated-sprint training on blood and muscle variables in well trained males and females are not well known. An understanding of changes to the blood and muscle during and following an exercise bout are important, so to gain an understanding of the type of stress and resulting adaptations that may occur. Also, while a large volume of research in training adaptations has been performed on males; little has been done on females. To date, some research indicates metabolism during moderateintensity exercise may differ between males and females; however, no study has compared repeated-sprint exercise. Therefore, it is unclear as to whether males and females would have a differing physiological response to repeated-sprint training. Purpose: The purpose of this study was to determine the effects of a repeated-sprint bout on molecular signalling in muscle and blood measures and heart rate in well-trained footballers. Additionally, we compared running times and sprint decrement (%). Research Design: Eight female senior University football players (Mean ± SD, age, 19 ± 1 y, VO ? 2peak 53.0 ± 5.1 ml·kg-1min-1) and seven male senior University football players (Mean ± SD, age, 19 ± 3 y, VO ? 2peak 59.0 ± 6.6 ml·kg-1min-1) volunteered to participate in this study. Participants performed four bouts of 6 x 30 m maximal sprints spread equally over a 40 min period. Sprint time was measured (at 30 m) for each sprint and sprint decrement was also calculated for all bouts. Muscle biopsies were taken from the vastus lateralis muscle at rest, 15 min following exercise and 2 h into recovery. Venous blood samples were taken at the same time points as the biopsies while capillary blood lactate was measured at rest and 3 min following each sprint bout. Repeated measures ANOVA and Post hoc t-tests were performed to determine significant differences between the two groups (male vs. female) and time points. Findings: Both groups had a significant (P<0.05) increase in blood lactate (mM) after the first bout of repeated sprints, with no differences between females (pre 0.9 ± 0.4 mM – post 10.0 ± 1.6 mM) and males (pre 0.8 ± 0.3 mM – post 10.0 ± 3.5 mM). Blood lactate remained elevated compared to rest (P<0.05) following bouts 2, 3 and 4 for both females (12.0 ± 3.6, 12.0 ± 3.3, 12.2 ± 3.8 mM respectively) and males (11.9 ± 2.9, 11.6 ± 2.3, 11.5 ± 4.0 mM respectively), with no differences between groups or time points (P>0.05). There were no differences (P>0.05) between the female and male athletes in mean heart rate attained at the end of each bout of repeated sprints (187 ± 2 v 190 ± 2 bpm respectively) or during recovery between sprints (140 ± 2 v 130 ± 2 bpm respectively). There were no differences between groups or time points in blood insulin (P>0.05). Fastest 30 m sprint time and mean 30 m sprint time during the repeated-sprint bout was faster for the males than females (4.58 ± 0.12 v 5.26 ± 0.27 s respectively; (P>0.05)). However, there were no differences in running velocity during the sprints between the males and females (165 ± 0.4 % vs. 155 ± 0.05 %; P>0.05) when expressed relative to velocity at VO ? 2peak (vVO ? 2peak). Also, mean % decrement during the repeated-sprint bout was lower in the males then females (4.9 ± 1.3 v 7.1 ± 1.9 % respectively; P<0.05). No changes were observed in total or phosphorylated Akt at any time-point or between genders. However, while total 4E-BP1 was lower, the ratio of total to phosphoryalated 4E-BP1 at rest was greater in males than females (P<0.05). Finally, there was also a significant decrease in 4E-BP1 phosphorylation post-exercise in males (P<0.05), but not females. Conclusions: There were no sex differences in blood lactate or heart rate throughout the repeated-sprint bout. These findings suggest that there were no cardio respiratory or lactate production/clearance differences in the response to a repeated-sprint-training bout between sexes. However, while males were faster than their female counterparts, the average relative speed was similar between sexes, suggesting a similar relative volume of work was performed during the sprint bouts. However, the females did have a greater decrement in sprint performance indicating a greater ability to recover sprint performance in the males. Sex differences in resting total and phosphorylated 4E-BP1 may indicate greater potential for muscle growth in the male athletes during basal conditions. However, differences could be due to factors other than sex, including previous training history. There was a lack of change in plasma insulin or Akt, but, similar to resistance exercise, a significant decrease in post-exercise 4E-BP1 phosphorylation for the males, but not females. The sex differences in the 4E-BP1 phosphorylation response post-exercise could be due to differences in the metabolic disturbance in the muscle during and following maximal sprints. Keywords: blood lactate, heart rate, muscle

Made available in DSpace on 2015-04-17T15:02:55Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1095042 bytes, checksum: e16a1b2bc5a20811d2f65ff33d39192b (MD5) Previous issue date: 2012-12-01 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / It is common to observe menopausal metabolic disorders that lead to weight gain and changes in glycemic control. Physical activity and zinc supplementation have been suggested as interventions to prevent weight gain and glucose metabolism disorders. Thus, this study aims to assess the effects of physical training and zinc supplementation on carbohydrate metabolism and weight control in ovariectomized rats. We used 60 Wistar divided into five groups: Sham (S), ovariectomized control (OX-C), ovariectomized + zinc supplementation (OX-Z), ovariectomized + physical training (OX-TF) and ovariectomized + zinc supplementation + physical training (OX-ZTF). Groups Z and ZTF received daily zinc supplementation (25mg/Kg body weight) in the form of oral ZnSO4.7H2O for eight weeks. Groups OX-TF and OX-ZTF performed a protocol of water jumps with gradual load increase three times a week for nine weeks. The parameters were analyzed using the paired and non-paired Student t test and one-way and two-way ANOVA with post hoc Newman-Keuls and MannWhitney test for nonparametric data (p <0.05). The ovariectomized control group (OX-C) showed higher feed intake and body weight compared to control group (Sham) (p <0.05). The OX-Z groups (16.20 ± 1.70g), OX-TF (17.28 ± 0.81g) and OX-ZTF (17.24 ± 1.71g) had lower food consumption, differently from the group OX -C (18.03 ± 0.98g), which had more value compared to the Sham group (16.39 ± 0.92g). Body weight was also higher in group OX-C (303 ± 33.89g) compared to Sham (245.2 ± 38.91 g) and zinc supplementation was the only intervention able to promote body weight lower in the group OX-Z (262.2 ± 24.16g). As for insulin, its concentration was significantly higher in group OX-ZTF (5.66 ± 0.99μIU / mL) compared to the group OX-C (3.40 ± 1.27 μIU / mL). Glycemia of the group X-Z (92.67 ± 7.28 mg/dL) was lower than the Sham group (122.0 ± 17.09 mg/dL). It is concluded that zinc supplementation was responsible for lower food consumption, which is related to maintenance of body weight. Furthermore, lower glucose levels were found in the zinc supplementation group, which may represent a better peripheral glucose uptake. The combination of zinc supplementation and physical training led to higher insulin concentration and physical performance, possibly due to the anabolic effects of this hormone on muscle hypertrophy. / É comum observar na menopausa distúrbios metabólicos que levam a aumento de peso e alterações da glicemia. A atividade física e a suplementação de zinco têm sido apontadas como intervenções capazes de prevenir o aumento de peso e os distúrbios do metabolismo glicêmico. Desta forma, esta pesquisa tem por objetivo avaliar os efeitos do treinamento físico e da suplementação com zinco sobre o metabolismo glicêmico e o controle de peso corporal em ratas ovariectomizadas. Utilizou-se 60 ratas Wistar divididas em cinco grupos: Sham (S), controle ovariectomizado (OX-C), Ovariectomizado+suplementação de zinco (OX-Z), ovariectomizado+treinamento físico (OX-TF) e ovariectomizado+zinco+treinamento físico (OX-ZTF). Os grupos OX-Z e OX-ZTF receberam diariamente suplementação de zinco (25mg/Kg de massa corporal) sob a forma de ZnSO4.7H2O via oral durante oito semanas. Os grupos OX-TF e OX-ZTF realizaram um protocolo de treinamento de resistência, utilizando saltos aquáticos com carga progressiva três vezes por semana durante nove semanas. Os parâmetros foram analisados por meio do teste t student pareado e ANOVA one way e two way com post hoc de Newman-Keuls e teste MannWhitney para dados não paramétricos (p<0,05). Os grupos OX-Z (16,20±1,70g), OX-TF (17,28±0,81g) e OX-ZTF (17,24±1,71g) apresentaram menor consumo alimentar, diferentemente do grupo OX-C (18,03±0,98g), que teve maior valor quando comparado ao grupo Sham (16,39±0,92g). A massa corporal também esteve maior no grupo OX-C (303±33,89g) em relação ao Sham (245,2±38,91g) e a suplementação de zinco foi a única intervenção capaz de promover massa corporal menor no grupo OX-Z (262,2±24,16g). Quanto à insulina, sua concentração foi significativamente maior no grupo OX-ZTF (5,66±0,99μIU/mL) em comparação ao grupo OX-C (3,40±1,27μIU/mL). A glicemia do grupo OX-Z (92,67±7,28mg/dL) foi menor que a do grupo Sham (122,0±17,09mg/dL). Conclui-se que suplementação de zinco foi responsável por menor consumo alimentar, o que pode está relacionado à manutenção do peso corporal. Além disso, houve menor glicemia no grupo da Suplementado com zinco, o que pode representar uma melhor captação periférica de glicose. Associando a Suplementação de zinco ao Treinamento físico se observou maior concentração de insulina e melhor desempenho físico, possivelmente pelos efeitos anabólicos deste hormônio sobre a hipertrofia muscular.

Recovery from exhaustive exercise in the white muscle of rainbow trout (Oncorhynchus mykiss) was used to examine the role of the adenylates in the control of energy metabolism and to assess the validity of equilibrium models of the behaviour of the high energy phosphates. The difficulty of obtaining muscle samples from fish makes detailed analysis of the behaviour of the labile high energy phosphates complex. The use of a new sampling procedure, the infusion of a lethal dose of anaesthetic via an indwelling cannula, minimized this problem. At exhaustion [ATP] and [PCr] were depressed by 75 and 80% respectively relative to the resting values. [ATP] depletion was mirrored by a stoichiometric increase in [IMP]. During recovery [PCr] returned to the resting level within 2 hours, but [ATP] recovery was slow and not complete until 24 hours post exercise. In contrast, energy charge and RATP(the proportion of the free adenylate pool phosphorylated to ATP) were, if anything, higher than the resting values by 2 hours post exercise. Therefore, [ATP] and energy status can be dissociated in tissues like fish white muscle because of the action of the purine nucleotide cycle. At 2 hours post exercise the calculated free ADP concentration dropped to less than one tenth the value at rest. As a result the [ATP] / [ADP] free ratio increased by nearly 6 fold. This condition may be required for glycogen resynthesis from lactate in muscle. Several similar equilibrium models of the behaviour of the adenylates and PCr were applied to the fish white muscle system. In general, the models well describe the relationship between the high energy phosphates. However, the definition of the high energy phosphate pool introduces some complications since this includes the total [ATP]. Because of the action of AMP deaminase the [ATP] concentration can change without measurable changes in the energy status, which is not considered in any of the models. As long as the extent of IMP formation is known the models can be applied, but since the formation of IMP may vary from fish to fish or with exercise regime the models lose much of their predictive power. / Science, Faculty of / Zoology, Department of / Graduate

Purpose: The purpose of our investigation was to compare repetition maximum (RM) to relative intensity using sets and repetitions (RISR) resistance training (RT) on measures of training load, vertical jump, and force production in well-trained lifters. Methods: Fifteen well-trained (isometric peak force= 4403.61+664.69 N, mean+SD) males underwent RT 3 d·wk-1 for 10-weeks in either an RM group (n=8) or RISR group (n=7). Weeks 8-10 consisted of a tapering period for both groups. The RM group achieved a relative maximum each day while the RISRgroup trained based on percentages. Testing at five time-points included unweighted ( Results: Moderate between-group effect sizes were observed for all SJ and CMJ conditions supporting the RISR group (g=0.76-1.07). A small between-group effect size supported RISR for allometrically-scaled isometric peak force (g=0.20). Large and moderate between-group effect sizes supported RISR for rate of force development from 0-50ms (g=1.25) and 0-100ms (g=0.89). Weekly volume load displacement was not different between groups (p>0.05), however training strain was statistically greater in the RM group (p<0.05). Conclusions: Overall, this study demonstrated that RISR training yielded greater improvements in vertical jump, rate of force development, and maximal strength compared to RM training, which may partly be explained by differences in the imposed training stress and the use of failure/non-failure training in a well-trained population.

The purpose of this study was to examine changes in muscle architecture and jumping performance in NCAA division I women's volleyball players throughout a competitive season and in preparation for conference championships. Ten women volleyball players were tested at preseason (T1), pretaper (T2), and post-taper (T3) on measures of vastus lateralis muscle thickness (MT), pennation angle (PA) and fascicle length (FL) using ultrasonography, and unloaded and loaded squat jump height (SJH) and peak power allometrically scaled to body mass (SJPPa) on a force platform. Rating of perceived exertion training load and strength training volume load were monitored weekly. Player's MT (p < 0.001, Glass's Δ = 2.8) and PA increased (p = 0.02, Δ = 3.9) after in-season training. However, MT decreased after the taper (p = 0.01, Δ = 0.6) but remained elevated above preseason values (p < 0.001, Δ = 1.7). There were no statistical changes in FL, SJH, or SJPPa. Large-to-very large negative relationships (r = −0.51 to −0.81) were observed between preseason relative maximal strength and changes in SJH and SJPPa with various loads over the season. These findings demonstrate that relatively low volumes of strength training and concurrent sport training during a tapering period are capable of preserving jumping performance, but not MT in women's volleyball players; however, jumping performance changes seem to be related to the player's strength level. Stronger players may benefit from an overreaching microcycle before the taper to preserve previously accrued muscular adaptations and jumping performance.

This paper develops a computer spreadsheet framework and model for estimating the individual benefits and costs of exercise for long run health. The biological costs and benefits rest on solid production functions between exercise intensity levels, fitness levels, and two key indices of long run health outputs—probability of all cause mortality and an index of health care costs. The less certain monetary estimates of those costs and benefits come from reviews of the key literature. The resulting model of individual exercise costs and benefits provides a basis for individual long run health planning plus cost effective and cost benefit analysis of different exercise strategies. The latter, which uses the implicit value of life, may provide insights to the lack of consistent exercise and strategies to increase it.

Purpose: To assess the effects of manipulating the loading of successive sets of midthigh clean pulls on the potentiation capabilities of 7 international-level US weightlifters (4 men, 3 women). Methods: Isometric and dynamic peak-force characteristics were measured with a force plate at 500 Hz. Velocity during dynamic pulls was measured using 2 potentiometers that were suspended from the top of the right and left sides of the testing system and attached to both ends of the bar. Five dynamic-performance trials were used (in the following order) as the potentiation protocol: women at 60, 80, 100, 120, and 80 kg and men at 60, 140, 180, 220, and 140 kg. Trials 2 vs 5 were specifically analyzed to assess potentiation capabilities. Isometric midthigh pulls were assessed for peak force and rate of force development. Dynamic lifts were assessed for peak force (PF), peak velocity (PV), peak power (PP), and rate of force development (RFD). Results: Although all values (PF, PV, PP, and RFD) were higher postpotentiation, the only statistically higher value was found for PV (ICCα = .95, P = .011, η2 = .69). Conclusions: Results suggest that manipulating set-loading configuration can result in a potentiation effect when heavily loaded sets are followed by a lighter set. This potentiation effect was primarily characterized by an increase in the PV in elite weightlifters.

Purpose: This paper attempts to develop production functions (PF) between aerobic exercise inputs and long-run health outputs. Future studies could use such PF for estimating the benefits and costs (broadly defined) of different exercise programs to help develop optimal (utility maximizing) ones. Methods: To develop the PF, the paper reviewed the biomedical literature for the major dose-response relations between health, physical fitness, and exercise. Where relevant, the paper converted the dose-response relationships from relative risks to absolute probabilities and standardized terminology and units of measures. Results: The paper develops a clear set of biological PF that illustrate, quantitatively, how increases in peak cardiorespiratory (CR) fitness as measured by a short stress test reduce the probability of all-cause mortality; how increasing intensities of short (approximately 30 min, three to five times a week) exercise sessions increase peak CR fitness or retard its age-related decline; and how consistent exercise reduces the risk of myocardial infarctions (MI). Conclusions: The exercise-long-run health PF developed in this paper should provide a useful framework for other studies to estimate the broadly defined costs and benefits of different exercise programs and to help develop optimal ones.

Daily undulating periodization (DUP), using daily alterations in repetitions, has been advocated as a superior method of resistance training, while traditional forms of programming for periodization (Block) have been questioned. Nineteen Division I track and field athletes were assigned to either a 10-week Block or DUP training group. Year and event were controlled. Over the course of the study, there were four testing sessions, which were used to evaluate a variety of strength characteristics, including maximum isometric strength, rate of force development, and one repetition maximum (1RM). Although, performance trends favored the Block group for strength and rate of force development, no statistical differences were found between the two groups. However, different (p ≤ 0.05) estimated volumes of work (VL) and amounts of improvement per VL were found between groups. Based upon calculated training efficiency scores, these data indicate that a Block training model is more efficient in producing strength gains than a DUP model. Additionally, alterations in testosterone (T), cortisol (C) and the T:C ratio were measured. Although there were no statistically (p ≤ 0.05) different hormone alterations between groups, relationships between training variables and hormone concentrations including the T:C ratio, indicate that Block may be more efficacious in terms of fatigue management.