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[Efeitos do pré-condicionamento isquêmico na força e no desempenho intermitente]

2025-12-10T02:02:49Z

Título: [Efeitos do pré-condicionamento isquêmico na força e no desempenho intermitente] Abstract: In sports competitions, enhancement in the smallest details may cause a significant difference in the final performance. Thus, sports scientists and coaches are always seeking for lawful competition-day interventions that may improve performance. In this context, a maneuver called ischemic preconditioning (IPC) has emerged. The IPC consists in repeated bouts of muscular ischemia followed by reperfusion performed on the proximal limbs (i.e., arms or thigh) before an exercise event. Despite several studies testing the IPC-induced effects on exercise performance in different types of exercise, the beneficial effects of IPC are still debatable. Even meta-analyses show heterogeneous conclusions, showing that more studies are necessary. Therefore, the aim of our study was to evaluate the effect of IPC on: a) high-intensity intermittent exercise and (b) maximal strength. In the first study fifteen players (15.5 ± 0.5 yrs) attended four trials separated by seven days in a counterbalanced randomized cross-over design: IPC (4 × 5-min occlusion 220 mmHg/reperfusion 0 mmHg) in each thigh; SHAM (similar to the IPC protocol but "occlusion" at 20 mmHg); IPC-A and SHAM-A similar to the IPC and SHAM, but with a moderate aerobic activity (70% of HRmáx) on reperfusion phases. After 6-min of each trial, the players performed the YoYo Intermittent Endurance Test level 1 (YoYoIE1). In the second study, fifteen recreational weight-lifters participated in a randomized cross over design, involving two sessions (IPC and SHAM), consisted of three cycles of 5 minutes of occlusion at 170 mm Hg of pressure (IPC) or 20 mmHg (SHAM), alternated by 5 minutes of reperfusion at 0 mm Hg. Ten minutes after, participants performed an 1-RM test on bench press. Our data didn’t found any effect of IPC on intermittent exercise and a slightly increase (~2.4%) on maximal strength, suggesting that IPC can possibly be an ergogenic aid for strength athletes. Tipo: Dissertação

Treinmento de força em mulheres na pós-menopausa: impacto do volume e da intensidade sobre a recomposição corporal e o desempenho físico funcional

2025-08-12T02:02:41Z

Título: Treinmento de força em mulheres na pós-menopausa: impacto do volume e da intensidade sobre a recomposição corporal e o desempenho físico funcional Abstract: Menopause is associated with sarcopenic obesity. The strength training can increase muscle mass and decrease body fat, resulting in body recomposition. This condition can be considered a therapeutic target against sarcopenic obesity. However, the most effective strength training program to optimize body recomposition in postmenopausal women remains an area of ongoing research. Thus, the aim of the present study was to investigate whether a strength training protocol with greater intensity and volume would result in greater improvements in body recomposition in postmenopausal women, and to determine whether changes in body recomposition would be associated with changes in physical-functional development and muscle strength. Thus, 43 postmenopausal women were randomly assigned to one of three groups: I) Single set with high load (SSHL, n=14, 1 set of 8 to 12 repetitions maximum), II) Single set with low load (SSLL, n=15, 1 set of 25 to 30 repetitions maximum), and III) Multiple sets with high load (MSHL, n=14, 3-6 sets of 8 to 12 maximum repetitions). We assessment body composition using DXA, physical-functional development using Timed Up and Go and sit and stand tests, and muscle strength using 1RM test. We quantified body recomposition using a composite z-score calculated as follows: (appendicular lean mass % delta z-score) + (-1x fat mass delta % z-score) / 2. Results showed a significant improvement in physical-functional development (P<0.001), significant reductions in visceral adipose tissue, total fat mass, and % fat (P=0.003, P=0.042, and P<0.001, respectively), and increases in muscle mass and strength (P<0.001), regardless of groups. Notably, the higher intensity groups (SSHL and MSHL) had a significantly greater body recomposition compared to the low intensity group (SSLL), especially after adjusting for age, physical activity, and sitting time (P=0.028). Therefore, the intensity of strength training is a critical factor in the body recomposition of postmenopausal women. Furthermore, the positive effects of body recomposition induced by strength training extend to physical-functional development and muscle strength. Tipo: Dissertação

Prevalência e caracterização de lesões musculoesqueléticas em competidores das categorias de base de karatê de acordo com a modalidade karatê e kumitê

2025-08-12T02:02:40Z

Título: Prevalência e caracterização de lesões musculoesqueléticas em competidores das categorias de base de karatê de acordo com a modalidade karatê e kumitê Abstract: Karate is a highly disseminated Japanese martial art that has been conquering many enthusiasts of all ages. This millenial combat is characterized in competitions by twofold: Katá and Kumite. Kata is defined as an individual demonstration of techniques in a predetermined sequence, while Kumite is real combat applying the techniques learned. Karate has been growing exponentially over time as well as the number of injuries in its practitioners. Like most sports, the practitioner is subject to musculoskeletal injuries that, when they occur, can cause important physical and socioeconomic consequences to athletes. Therefore, knowledge of the epidemiological factors related to the appearance of these injuries is essential, especially when referring to the particularities of the modality. There is little data in the literature, in general, on the epidemiological characteristics of injuries involving karate in younger competitors. The influence of base categories on the prevalence of these injuries has been little disseminated, as well as the characteristics of injuries that happens in the most affected anatomical segment in this population. The objective of the study was to investigate the incidence and anatomical sites most affected by musculoskeletal injuries in competitors of the special division of the base category of kata and kumite modalities. The survey had the participation of 99 competitors from the base categories (14 to 21 years old), being 42 male competitors and 57 female competitors, participants of significant competitions such as state, national and international championships. Participants were divided into 3 groups according to the modality they attended in competitions, namely: only kata (n=12), only kumite (n=43) and kata and kumite (n=44). Everyone answered a closed questionnaire containing personal data, sports and injuries background. The data obtained through the questionnaires applied to the athletes were treated and statistically tabulated in a descriptive way (mean, standard deviation, frequency and percentages). 77 competitors, corresponding to 77.8% of the sample, reported having already suffered an injury. The most affected areas were the lower limbs, with a prevalence of the knee with 56.57%. There was no significant difference between injury sites in kata and kumite competitors. Older and higher ranked competitors were more susceptible to sports injuries. Tipo: Dissertação

Relação entre o nível de aptidão física, modulação autonômica cardíaca e posicionamento tático em jogadores de futebol da categoria sub-17

2025-08-09T02:02:40Z

Título: Relação entre o nível de aptidão física, modulação autonômica cardíaca e posicionamento tático em jogadores de futebol da categoria sub-17 Abstract: Soccer is an acyclic sport modality characterized by intermittent efforts with short recovery intervals between actions, where players perform sprints, runs and walks, alternating low and high intensity efforts. Although aerobic metabolism provides the highest proportion of energy for activities during matches, football also triggers metabolic demands and anaerobic fitness in its players. As it is the modality with the most appreciators in the world, this exhibition attracts high investment in large professional clubs, including in the area of physical performance analysis, tactical technical profile and sports medicine. Following this trend, there are numerous protocols for physiological assessment in soccer, however, coaches, physical trainers and physiologists have increasingly sought to identify new methodologies that can be used to enhance performance and avoid greater physical strain on players. Physiological adaptations have also been monitored through heart rate variability (HRV) responses, which can provide useful information regarding changes in physical and training status, as well as being associated with improvements in the athletic performance of players. Currently, there are limited studies in the literature that evaluate the association between cardiac autonomic function, physical performance and tactical position in soccer, especially in the base categories. The objective of the present study was to verify if the tactical actions of the different positions of the soccer field are associated with the HRV at rest and the performance in players of the Sub-17 category. Fifty-nine male players aged 16.1 ± 1.41 years voluntarily participated in this study and were subdivided into 5 categories: goalkeepers (n=10), fullbacks (n=13), wingers (n=15), midfielders (n=11) and attackers (n=10). Baseline hemodynamic parameters and HRV were assessed under resting conditions. Physical tests were carried out to verify the physical fitness of the players. The full-backs had a greater resting cardiac vagal modulation than all other players (p<0.05), as well as a lower resting HR compared to goalkeepers (p<0.001) and forwards (p=0.039). Greater VO2max and distance covered in the Yo-Yo IR1 test were observed in wingers players in relation to all players in other positions (p<0.05). Similar results were observed regarding the agility tests, where lateral players had the lowest execution time compared to other groups of players (p<0.05). Significant correlations were identified between cardiac vagal indices and physical fitness according to positions on the soccer field. Our data allow us to conclude that wing players had higher values of vagal activity and these findings were associated with greater physical performance. Tipo: Dissertação