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Vila Real de Santo António, Portugal

Leitao R.B.,Polytechnic Institute of Viana do Castelo | Rodrigues L.P.,Polytechnic Institute of Viana do Castelo | Rodrigues L.P.,Research Center in Sports Science | Neves L.,Polytechnic Institute of Viana do Castelo | Carvalho G.S.,University of Minho
International Journal of Adolescent Medicine and Health | Year: 2013

Aim: It has been suggested that the decline in menarcheal age is associated with the increase of obesity prevalence. Objective: To examine the association between age at menarche and adiposity development from age 7 to 15 years. Subjects: A cohort of 109 schoolgirls from Viana do Castelo (Northern Portugal). Methods: Anthropometric measurements (height, weight, and triceps and subscapular skinfold thicknesses) were longitudinally obtained at 7, 8, 9, and 15 years. Waist circumference and self-reported age at menarche were obtained at age 15. Obesity was defined by the cut-off value of 30% body fat. Ages of <12 years, 12-13 years, and >13 years were classified as early menarche (EM), average menarche (AM) and late menarche (LM), respectively. Results: Median menarcheal age was 12.0 years (range, 8-15 years), with 26.6% of girls classified as EM. Compared with their LM peers, EM girls were always fatter (p=0.001) and had higher waist circumference at age 15 (p=0.009). All variables showed significant negative associations with age at menarche, except subscapular to triceps skinfold ratio at all ages and height at age 15. At both ages 9 and 15 years, LM girls had the lowest prevalence of obesity (4.5% and 9.1%, respectively). The 8-year incidence of obesity in EM girls was 24.1%, while that in the AM plus LM group was 13.8% (p=0.005). Conclusion: EM seems to be a risk factor for the development of obesity during adolescence. However, this vulnerability may start to be programmed before menarche as girls with precocious menarche were already fatter than their late-maturing peers at age 7 years. © 2013 by Walter de Gruyter Berlin Boston 2013. Source

Marmeleira J.,University of Evora | Marmeleira J.,Research Center in Sports Science
European Review of Aging and Physical Activity | Year: 2013

Physical activity positively influences brain health and cognitive functioning in older adults. Several physiological and psychological mechanisms have been identified to underlie such a relationship. Cardiovascular fitness is accompanied with changes in mechanisms such as cerebral blood flow, neurotrophic factors, neurotransmitter systems and neural architecture that have themselves been associated with cognitive performance. Factors associated with exercise such as arousal, mood and self-perception of competence seem also to influence cognitive performance. Other explanation for the benefits of exercise in cognition, results from the fact that the performance of motor skills involve an important cognitive component (e.g., executive functions and information processing speed). Evidence of brain plasticity and behavior has been provided from studies where animals are exposed to enriched or complex environments. Exposure to such paradigms in which physical activity plays an important role has been found to influence various aspects of brain function and structure. Studies using neuroimaging techniques have established a link between the acquisition of different motor skills and the occurrence of neuroplasticity in human adults. This literature review indicates that the type of exercise and its specific perceptual and cognitive characteristics may influence cognitive performance. However, most of the research has been focused on self-paced movements or automatized skills and few intervention studies have examined the results of merging exercise and cognitive training in a single program. An important scientific challenge for the coming years is to design exercise programs capable of mobilizing several type of mechanisms underlying the effects of physical activity on brain and cognition. © 2012 European Group for Research into Elderly and Physical Activity (EGREPA). Source

Lopes V.P.,Research Center in Sports Science | Lopes V.P.,Polytechnic Institute of Braganca | Rodrigues L.P.,Polytechnic Institute of Viana do Castelo | Maia J.A.R.,University of Porto | And 2 more authors.
Scandinavian Journal of Medicine and Science in Sports | Year: 2011

This study considers relationships among motor coordination (MC), physical fitness (PF) and physical activity (PA) in children followed longitudinally from 6 to 10 years. It is hypothesized that MC is a significant and primary predictor of PA in children. Subjects were 142 girls and 143 boys. Height, weight and skinfolds; PA (Godin-Shephard questionnaire); MC (Körperkoordination Test für Kinder); and PF (five fitness items) were measured. Hierarchical linear modeling with MC and PF as predictors of PA was used. The retained model indicated that PA at baseline differed significantly between boys (48.3MET/week) and girls (40.0MET/week). The interaction of MC and 1 mile run/walk had a positive influence on level of PA. The general trend for a decrease in PA level across years was attenuated or amplified depending on initial level of MC. The estimated rate of decline in PA was negligible for children with higher levels of MC at 6 years, but was augmented by 2.58 and 2.47 units each year, respectively, for children with low and average levels of initial MC. In conclusion MC is an important predictor of PA in children 6-10 years of age. © 2009 John Wiley & Sons A/S. Source

Vila-Cha C.,Polytechnic Institute of Guarda | Vila-Cha C.,Research Center in Sports Science | Falla D.,University of Gottingen
Journal of Electromyography and Kinesiology | Year: 2016

This study evaluates and compares the effects of strength and endurance training on motor unit discharge rate variability and force steadiness of knee extensor muscles. Thirty sedentary healthy men (age, 26.0 ± 3.8 yrs) were randomly assigned to strength training, endurance training or a control group. Conventional endurance and strength training was performed 3 days per week, over a period of 6 weeks. Maximum voluntary contraction (MVC), time to task failure (at 30% MVC), coefficient of variation (CoV) of force and of the discharges rates of motor units from the vastus medialis obliquus and vastus lateralis were determined as subjects performed 20% and 30% MVC knee extension contractions before and after training. CoV of motor unit discharges rates was significantly reduced for both muscles following strength training (P < 0.001), but did not change in the endurance (P = 0.875) or control group (P = 0.995). CoV of force was reduced after the strength training intervention only (P < 0.01). Strength training, but not endurance training, reduces motor unit discharge rate variability and enhances force steadiness of the knee extensors. These results provide new insights into the neuromuscular adaptations that occur with different training methods. © 2015 Elsevier Ltd. Source

Marmeleira J.F.F.,Research Center in Sports Science | Marmeleira J.F.F.,University of Evora | Aldeias N.M.C.,University of Evora | Medeira da Graca P.M.S.,University of Evora
European Physical Education Review | Year: 2012

The main aim of this study was to evaluate the physical activity (PA) levels of high school Portuguese students during physical education (PE) and investigate the association of PA levels with students' goal orientation and intrinsic motivation. Forty-six students from three high schools participated. Heart rate telemetry and pedometry were used to assess PA and the Borg rate of perceived exertion scale was used to measure perceived exertion. Thirty PE lessons were monitored. The results indicated that high school PE lessons involve low levels of PA. Students engaged in moderate to vigorous PA (MVPA) only in about one-third (29.7 minutes) of the official PE scheduled time (90 minutes) and perceived exertion as light. In general, students seemed to be positively motivated toward PE and mainly task goal orientated. Boys felt more enjoyment/interest and perceived their competence in more positive ways than girls. The number of steps and the rate of perceived exertion were associated with levels of PA measured by heart rate telemetry. Intrinsic motivation and goal orientation were not related with MVPA. © The Author(s) 2012. Source

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