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  • Author: Manuel J. Coelho-e-Silva x
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António J. Figueiredo, Manuel J. Coelho e Silva, Sean P. Cumming and Robert M. Malina

The purpose of the study was to compare the anthropometric, functional and sport-specific skill characteristics and goal orientations of male youth soccer players at the extremes of height and skeletal maturity in two competitive age groups, 11–12 and 13–14 years. The shortest and tallest players, and least and most skeletally mature players (n = 8 per group) within each age group were compared on chronological age; skeletal age (Fels method); pubertal status (pubic hair); size, proportions and adiposity; four functional capacities; four soccer-specific skills; and task and ego orientation. The tallest players were older chronologically, advanced in maturity (skeletal, pubertal) and heavier, and had relatively longer legs than the shortest players in each age group. At 11–12 years, the most mature players were chronologically younger but advanced in pubertal status, taller and heavier with more adiposity. At 13–14 years, the most mature players were taller, heavier and advanced in pubertal status but did not differ in chronological age compared with the least mature players. Players at the extremes of height and skeletal maturity differed in speed and power (tallest > shortest; most mature > lest mature), but did not differ consistently in aerobic endurance and in soccer-specific skills. Results suggested that size and strength discrepancies among youth players were not a major advantage or disadvantage to performance. By inference, coaches and sport administrators may need to provide opportunities for or perhaps protect smaller, skilled players during the adolescent years.

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Humberto M. Carvalho, Manuel J. Coelho-e-Silva, Joey C. Eisenmann and Robert M. Malina

Relationships among chronological age (CA), maturation, training experience, and body dimensions with peak oxygen uptake (VO2max) were considered in male basketball players 14–16 y of age. Data for all players included maturity status estimated as percentage of predicted adult height attained at the time of the study (Khamis-Roche protocol), years of training, body dimensions, and VO2max (incremental maximal test on a treadmill). Proportional allometric models derived from stepwise regressions were used to incorporate either CA or maturity status and to incorporate years of formal training in basketball. Estimates for size exponents (95% CI) from the separate allometric models for VO2max were height 2.16 (1.23–3.09), body mass 0.65 (0.37–0.93), and fat-free mass 0.73 (0.46–1.02). Body dimensions explained 39% to 44% of variance. The independent variables in the proportional allometric models explained 47% to 60% of variance in VO2max. Estimated maturity status (11–16% of explained variance) and training experience (7–11% of explained variance) were significant predictors with either body mass or estimated fat-free mass (P ≤ .01) but not with height. Biological maturity status and training experience in basketball had a significant contribution to VO2max via body mass and fat-free fat mass and also had an independent positive relation with aerobic performance. The results highlight the importance of considering variation associated with biological maturation in aerobic performance of late-adolescent boys.

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Robert M. Malina, Sean P. Cumming and Manuel J. Coelho e Silva

“Gaps in Our Knowledge” are discussed in the context of the need to integrate biological and behavioral factors in a biocultural approach to physical activity and movement proficiency. Specific issues considered include outdoor play, organized and informal activity, biological maturation, tracking of activity, development of movement proficiency, and individual differences. Studies considered are largely based on youth in economically better-off, developed countries in the western culture context. There is a need to extend studies of physical activity and movement proficiency to different cultural contexts.

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Joric B. Vandendriessche, Barbara Vandorpe, Manuel J. Coelho-e-Silva, Roel Vaeyens, Matthieu Lenoir, Johan Lefevre and Renaat M. Philippaerts

Discussions of growth and motor performance of children are often set in the context of physical fitness. Although there is a clear theoretical concept or definition of fitness comprising motor coordination, the latter is not systematically considered. This study determined to what extent the variance in motor coordination might be explained by morphological and fitness characteristics. To postulate understanding of this association during childhood, 613 boys aged 7–11 years completed the morphological measurements, the Körperkoordinationstest für Kinder (KTK) and different fitness tests. The results demonstrated a substantial interrelationship among morphology, fitness and motor coordination in elementary school boys. The magnitude of explained variance and the loadings of the canonical correlation between the several constructs are strongly pronounced during childhood indicating that these constructs should be well considered given their contribution to a child’s general development.

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Aristides M. Machado-Rodrigues, Manuel J. Coelho e Silva, Jorge Mota, Rute Marina Santos, Sean P. Cumming and Robert M. Malina

Background:

Sport has high social valence and is a primary context for physical activity for the majority of youth. The aim of this study was to estimate the contribution of participation in organized sport to the total daily energy expenditure and also to its moderate-to-vigorous portion in male adolescents.

Methods:

The sample comprised 165 Portuguese male youth, aged 13 to 16 years. Physical activity was assessed with a multi-method approach (Actigraph GT1M accelerometer plus 3-day diary record). Differences in the intensities of physical activity and sedentary behavior of male sport participants and nonsport participants were compared using independent sample t-test.

Results:

Male participants in organized sports spent significantly more time in moderate-to-vigorous activities than nonparticipants, although the P-value for the 15 to 16 years age-group was marginal (P = .08) on the weekend days. In addition, male adolescents spent 11% to 13% of total daily energy expenditure in organized sports which corresponded to 35% to 42% of the moderate-to-vigorous portion of daily energy expenditure.

Conclusion:

Organized sport appears to be a relevant component of daily activity energy expenditure to promote healthy lifestyles among male adolescents.

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Susana Cristina Araújo Póvoas, Peter Krustrup, Carlo Castagna, Pedro Miguel Ribeiro da Silva, Manuel J. Coelho-e-Silva, Rita Liliana Mendes Pereira and Malte Nejst Larsen

Purpose: To examine the reliability of age-adapted submaximal Yo-Yo (Yo-Yosubmax) intermittent tests in untrained schoolchildren aged 9–16 years (n = 139; 72 boys and 67 girls) and within children with high and low percentage of body fat (%BF). Methods: Yo-Yo intermittent recovery level 1 children’s (YYIR1C), Yo-Yo intermittent endurance level 1 (YYIE1), and Yo-Yo intermittent endurance level 2 (YYIE2) tests were performed 7 days apart by 9- to 11-, 12- to 13-, and 14- to 16-year-old children, respectively. Reliability was tested for Yo-Yosubmax heart rate (HRsubmax), peak HR, and maximal distance. Results: HRsubmax typical errors of measurement (TEM) in YYIR1C, YYIE1, and YYIE2 were 2.2% (1.7%–2.9%), 2.4% (1.9%–3.3%), 1.9% (1.6%–2.5%) and 2.4% (1.9%–3.3%), 2.4% (1.9%–3.2%), 1.9% (1.5%–2.4%) for girls and boys, respectively. HRsubmax intraclass correlation coefficient values were good to excellent (.62–.87) in all age groups and in schoolchildren of different %BF. TEM for HRsubmax ranged from 2.1% to 2.3% in high and low %BF groups. Maximal distance intraclass correlation coefficients were excellent and TEM values ranged from 11% to 12% in both %BF groups. HRsubmax was moderately to largely associated (r = −.46 to −.64; P < .002) with Yo-Yo maximal distance across the age groups. Conclusion: Yo-Yosubmax tests are a reliable tool providing useful and sustainable aerobic performance testing in physical education, irrespective of individual %BF.

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João Valente-dos-Santos, Manuel J. Coelho-e-Silva, Filipe Simões, Antonio J. Figueiredo, Neiva Leite, Marije T. Elferink-Gemser, Robert M. Malina and Lauren Sherar

This study evaluates the contributions of age, growth, skeletal maturation, playing position and training to longitudinal changes in functional and skill performance in male youth soccer. Players were annually followed over 5 years (n = 83, 4.4 measurements per player). Composite scores for functional and skill domains were calculated to provide an overall estimate of performance. Players were also classified by maturity status and playing position at baseline. After testing for multicollinearity, two-level multilevel (longitudinal) regression models were obtained for functional and skill composite scores. The scores improved with age and training. Body mass was an additional predictor in both models [functional (late maturing): 13.48 + 1.05 × centered on chronological age (CA)—0.01 × centered CA2—0.19 × fat mass (FM) + 0.004 × annual volume training—1.04 × dribbling speed; skills (defenders): 7.62 + 0.62 × centered CA—0.06 × centered CA2 + 0.04 × fat-free mass—0.03 × FM + 0.005 × annual volume training—0.19 × repeated-sprint ability + 0.02 × aerobic endurance]. Skeletal maturity status was a significant predictor of functional capacities and playing position of skill performance. Sound accuracy of each multilevel model was demonstrated on an independent cross-sectional sample (n = 52).

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Ricardo Ribeiro Agostinete, Santiago Maillane-Vanegas, Kyle R. Lynch, Bruna Turi-Lynch, Manuel J. Coelho-e-Silva, Eduardo Zapaterra Campos, Suziane Ungari Cayres and Romulo Araújo Fernandes

Purpose: To investigate the mediating effect of muscle mass on the relationship between training load and bone density in adolescent swimmers. Methods: A cross-sectional study involving 87 control and 22 swimmers aged 10–19 years (overall sample: n = 109). Swimmers had a minimum of 1 year of competition in regional and national championships, and control adolescents reported 1 year without any organized sport. Bone density was the main outcome (dual-energy X-ray absorptiometry), which was measured in upper limbs, lower limbs, spine, and whole body. Monthly training load was the independent variable, while the mediation effect of lean soft tissue was assessed. Maturity offset, age, inflammation, and vitamin D intake were treated as covariates. Results: Swimmers had lower bone density than controls; there was a significant and positive relationship between training load and muscle mass. In boys, training load presented a negative correlation with bone density in lower limbs [r = −.293; 95% confidence interval (CI), −.553 to −.034]. In girls, training load was negatively related to bone mineral density in lower limbs (r = .563; 95% CI, −.770 to −.356) and whole body (r = −.409; 95% CI, −.609 to −.209). Conclusion: Training load had a negative relationship on bone density of swimmers of both sexes, independently of the positive effect of lean soft tissue on bone density.

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Aristides M. Machado Rodrigues, Manuel J. Coelho e Silva, Jorge Mota, Sean P. Cumming, Lauren B. Sherar, Helen Neville and Robert M. Malina

Sex differences in physical activity (PA) through pubertal maturation and the growth spurt are often attributed to changing interests. The contribution of sex differences in biological maturation to the adolescent decline has received limited attention. This study examined the contribution of somatic maturation to sex differences in objective assessments of sedentary behavior and PA in Portuguese adolescents (N = 302, aged 13–16 years). Maturation was estimated from the percentage of predicted mature stature and physically active and inactive behaviors assessed with Actigraph GT1M accelerometers. The influence of age, sex and their interaction on body size, maturation and physical behaviors were examined using factorial ANOVA and, subsequently, ANCOVA (controlling for maturation) tested the effect of sex. Males spent more time in MVPA and less time in sedentary behavior than females. However, sex differences were attenuated when maturation was controlled; thus suggesting that maturity may play an important role in adolescent behaviors.

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Aristides M. Machado-Rodrigues, Neiva Leite, Manuel J. Coelho e Silva, João Valente-dos-Santos, Raul A. Martins, Luis PG Mascarenhas, Margaret CS Boguszewski, Cristina Padez and Robert M. Malina

Background:

Associations of metabolic syndrome (MetS) with lifestyle behaviors in youth is potentially important for identifying subgroups at risk and encourage interventions. This study evaluates the associations among the clustering of metabolic risk factors and moderate-to-vigorous physical activity (MVPA) in youth.

Methods:

The sample comprised 522 girls and 402 boys (N = 924) aged 11 to 17 years. Height, weight, waist circumference (WC), fasting glucose, high-density lipoprotein cholesterol, triglycerides, and blood pressures were measured. Cardiorespiratory fitness (CRF) was assessed using the 20-m shuttle run test. MVPA was estimated with a 3-day diary. Outcome variables were statistically normalized and expressed as z scores. A clustered metabolic risk score was computed as the mean of z scores. Multiple linear regression was used to test associations between metabolic risk and MVPA by sex, adjusted for age, WC, and CRF.

Results:

After adjustment for potential confounders, MVPA was inversely associated with the clustering of metabolic risk factors in girls, but not in boys; in addition, after adjusting for WC, the statistical model of that relationship was substantially improved in girls.

Conclusion:

MVPA was independently associated with increased risk of MetS in girls. Additional efforts are needed to encourage research with different analytical approach and standardization of criteria for MetS in youth.