Browsing by Author "Alves, Ana R."
Now showing 1 - 5 of 5
Results Per Page
Sort Options
- Concurrent training in prepubertal children: An updatePublication . Alves, Ana R.; Marta, Carlos C.; Neiva, Henrique; Izquierdo, Mikel; Marques, MCThis paper affords an update review over the state of art regarding the importance of physical fitness and the significance of different combination approaches between resistance and aerobic training, as well as conditioning methods exercise alone on physical fitness improvements, specifically explosive strength and cardiorespiratory fitness in prepubertal children. The main research conclusions can be summarized as: i) Resistance training can be reliable to improve muscle strength in prepubertal children; ii) A proper and quantifiable exercise frequency and intensity in aerobic training remains unclear; iii) No differences have been found between prepubertal girls and boys on strength and aerobic capacity improvements after intra- session concurrent training , resistance or aerobic training alone; iv) In adults, concurrent resistance and aerobic training seems to be more effective on improvements of aerobic capacity than aerobic training alone; v) Aerobic training biomechanically specific to the concurrent resistance training may minimize adaptation interference when concurrently training; vi) In adolescents, concurrent resistance and aerobic training is equally effective to improve explosive strength compared to resistance training alone, and more efficient in aerobic capacity than resistance training alone; vii) Optimum training sequence was determined by the individual purposes of the training program; viii) Performing aerobic prior to resistance training produces endurance gains, while performing resistance prior to aerobic training appears to be more adequate to obtain strength improvements; ix) In adults, performing concurrent training in different sessions seems to be more effective to improve muscular strength than intra-session concurrent training. These results can be helpful for coaches, teachers and researchers to optimize explosive strength and cardiorespiratory fitness training in sports club and school-based programs, as well as a reliable source for further researches
- Effects of order and sequence of resistance and endurance training on body fat in elementary school-aged girlsPublication . Alves, Ana R.; Marta, Carlos C.; Neiva, Henrique; Izquierdo, Mikel; Marques, Mário CThe purpose of this study was to analyse the effects of order and sequence of concurrent resistance and endurance training on body fat percentage (BFP) in a large sample of elementary school-aged girls. One hundred and twenty-six healthy girls, aged 10-11 years (10.95 ± 0.48 years), were randomly assigned to six groups to perform different training protocols per week for 8 weeks: Resistance-only (R), Endurance-only (E), Concurrent Distinct Endurance-Resistance (CDER), Concurrent Parallel Endurance-Resistance (CPER), Concurrent Parallel Resistance-Endurance (CPRE), and a Control group (C). In R and E, the subjects performed single sessions of resistance or endurance exercises, respectively (two days per week). In CDER, resistance-endurance training was performed on different days each week (four days per week). CPER and CPRE performed single-session combined endurance-resistance training or combined resistance-endurance training, respectively, each week (two days per week). After an 8-week training period, BFP decreased in all experimental groups (CPER: 13.3%, p< 0.05; CPRE: 13.8%, p<0.001; E: 1.9%, p>0.05; R: 5.0%, p>0.05; and CDER: 5.6%, p>0.05). However, a significant difference was found in CPER and CPRE when compared to CDER, E, and R, indicating that training sequence may influence BFP. All programmes were effective, but CPER and CPRE obtained better results for BFP than CDER, E, or R. The effects of concurrent resistance and endurance training on body fat percentage can be mediated by order and sequence of exercise. These results provide insight into optimization of school-based fat loss exercise programmes in childhood.
- Effects of Suspension Versus Traditional Resistance Training on Explosive Strength in Elementary School-Aged BoysPublication . Marta, Carlos C.; Alves, Ana R.; Esteves, Pedro Tiago; Casanova, Natalina; Marinho, Daniel; Neiva, Henrique; Aguado-Jimenez, Roberto; Alonso-Martínez, Alicia M.; Izquierdo, Mikel; Marques, MCPurpose: The aim of this study was to determine the effects of an 8-week program of resistance training (RT) or suspension training (ST) on explosive strength in prepubescent boys. Methods: Fifty-seven boys aged 10–11 years were assigned to 2 training groups, RT or ST or a control group (no training program). Boys trained twice weekly for 8 weeks. Results: A significant interaction was reported with a large (P < .001, η2p = .463), medium (P < .001, η2p = .395), and small effect sized (P ≤ .001, η2p = .218) in the 1-kg ball throw, 3-kg ball throw, and time-at-20-m test, respectively. There was no significant interaction in the countermovement vertical jump or the standing long jump. Changes from preintervention to postintervention for the 1-kg ball throw were 5.94% and 5.82% for the ST and RT, respectively, and 8.82% and 8.14% in the 3-kg ball throw for the ST and RT, respectively. The improvement in the 20-m sprint was 1.19% for the ST and 2.33% for the RT. Conclusion: Traditional RT and ST seem to be effective methods for improving explosive strength in prepubescent boys. ST could be considered as an alternative modality to optimize explosive strength training in school-based programs.
- Modeling Fitness Variable Responses To Training In Prepubescent ChildrenPublication . Alves, Ana R.; Marta, Carlos C.; Neiva, Henrique; Nunes, Célia; Izquierdo, Mikel; Marques, MCThe aim of this study was to determine strength and oxygen uptake (VO2max) performances according to different training program intervention design with 8-weeks duration in prepubescent children through a multiple linear regression models. Two hundred and forty-five healthy prepubescent children (aged 10.9 ± 0.5 years) were randomly assigned to a specific training program (strength training only - S; aerobic training only - A; intra-session aerobic and strength training - AS; intra-session strength and aerobic training - SA; or concurrent training performed in different sessions - CT) or a control group (no training regimen - C). It was possible to develop indirect predictive models for each training method, by including each variable pre-training, body fat percentage and body mass index. The models provided explained 82% of variance in the VO2max, 98% in the 1kg ball-throw, 96% in the 3kg ball-throw, 92% in the counter-movement jump, 93% in the standing long jump and 98% in the 20m sprint performances. This novel approach to training evaluation and control aims to provide a tool to allow professionals to calculate changes with a high confidence level (CI 95%), to control gains and to choose the best training methodology to apply according to the defined purposes. The results of this study could be a great support to teachers, coaches and professionals providing important tools to improve the efficacy and individualization of training.
- Natural Transformation as a Mechanism of Horizontal Gene Transfer in Aliarcobacter butzleriPublication . Bonifácio, Marina; Mateus, Cristiana; Alves, Ana R.; Maldonado, Emanuel; Duarte, Ana Paula; Domingues, Fernanda; Oleastro, Mónica; Ferreira, SusanaAliarcobacter butzleri is an emergent enteropathogen, showing high genetic diversity, which likely contributes to its adaptive capacity to different environments. Whether natural transformation can be a mechanism that generates genetic diversity in A. butzleri is still unknown. In the present study, we aimed to establish if A. butzleri is naturally competent for transformation and to investigate the factors influencing this process. Two different transformation procedures were tested using exogenous and isogenic DNA containing antibiotic resistance markers, and different external conditions influencing the process were evaluated. The highest number of transformable A. butzleri strains were obtained with the agar transformation method when compared to the biphasic system (65% versus 47%). A. butzleri was able to uptake isogenic chromosomal DNA at different growth phases, and the competence state was maintained from the exponential to the stationary phases. Overall, the optimal conditions for transformation with the biphasic system were the use of 1 µg of isogenic DNA and incubation at 30 ◦C under a microaerobic atmosphere, resulting in a transformation frequency ~8 × 10−6 transformants/CFU. We also observed that A. butzleri favored the transformation with the genetic material of its own strain/species, with the DNA incorporation process occurring promptly after the addition of genomic material. In addition, we observed that A. butzleri strains could exchange genetic material in co-culture assays. The presence of homologs of well-known genes involved in the competence in the A. butzleri genome corroborates the natural competence of this species. In conclusion, our results show that A. butzleri is a naturally transformable species, suggesting that horizontal gene transfer mediated by natural transformation is one of the processes contributing to its genetic diversity. In addition, natural transformation can be used as a tool for genetic studies of this species.