Maturational and social factors contributing to relative age effects in school sports: Data from the London Youth Games.

Few studies have investigated whether relative age effects (RAEs) exist in school sport. None have sought to test the competing maturational and social-agent hypotheses proposed to explain the RAE. We aimed to determine the presence of RAEs in multiple school sports and examine the contribution of maturational and social factors in commonplace school sports. We analyzed birth dates of n=10645 competitors (11-18 years) in the 2013 London Youth Games annual inter-school multisport competition and calculated odds ratio (OR) for students competing based on their yearly birth quarter (Q1-Q4). Multivariate logistic regression was used to determine the relative contribution of constituent year (Grade) and relative age in netball and football which used multiyear age groupings. In girls, RAEs were present in the team sports including hockey, netball, rugby union, cricket and volleyball but not football. In boys, RAEs were stronger in common team sports (football, basketball cricket) as well as athletics and rowing. In netball and football teams with players from two constituent years, birth quarter better-predicted selection than did constituent year. Relatively older players (Q1) from lower constituent years were overrepresented compared with players from Q3 and Q4 of the upper constituent years. RAEs are present in the many sports commonplace in English schools. Selection of relatively older players ahead of chronologically older students born later in the selection year suggests social agents contribute to RAEs in school sports.

Pilot investigation of the oxygen demands and metabolic cost of incremental shuttle walking and treadmill walking in patients with cardiovascular disease.

OBJECTIVE: To determine if the metabolic cost of the incremental shuttle-walking test protocol is the same as treadmill walking or predicted values of walking-speed equations. SETTING: Primary care (community-based cardiac rehabilitation). PARTICIPANTS: Eight Caucasian cardiac rehabilitation patients (7 males) with a mean age of 67±5.2 years. PRIMARY AND SECONDARY OUTCOME MEASURES: Oxygen consumption, metabolic power and energy cost of walking during treadmill and shuttle walking performed in a balanced order with 1 week between trials. RESULTS: Average overall energy cost per metre was higher during treadmill walking (3.22±0.55 J kg/m) than during shuttle walking (3.00±0.41 J kg/m). There were significant post hoc effects at 0.67 m/s (p<0.004) and 0.84 m/s (p<0.001), where the energy cost of treadmill walking was significantly higher than that of shuttle walking. This pattern was reversed at walking speeds 1.52 m/s (p<0.042) and 1.69 m/s (p<0.007) where shuttle walking had a greater energy cost per metre than treadmill walking. At all walking speeds, the energy cost of shuttle walking was higher than that predicted using the American College of Sports Medicine walking equations. CONCLUSIONS: The energetic demands of shuttle walking were fundamentally different from those of treadmill walking and should not be directly compared. We warn against estimating the metabolic cost of the incremental shuttle-walking test using the current walking-speed equations.

Contrasting physical activity patterns in children and adolescents living in differing environments in the U.K.

AIMS: There is evidence for lower physical activity (PA) in rural adults; it is important to evaluate how the environment influences the PA of children and adolescents. METHODS: We compared the PA of 6485 English 10-15.9 year olds according to two systems for classifying the immediate environment. System one compared urban and rural areas. System two compared urban, town and fringe, and rural areas. Analyses were carried out separately for children (<13 years) and adolescents (>13 years). RESULTS: Rural children were more active than those from urban areas (OR 1.38, 95% CI 1.15-1.66) as were adolescents (OR 1.30, 95% CI 1.11-1.51). Using trilateral division, children were more active if they lived in town and fringe (OR 1.32, 95% CI 1.03-1.67) or rural (OR 1.45, 95% CI 1.14-1.84) areas compared with urban areas. Adolescents from town and fringe areas were more active than urban dwellers (OR 1.50, 95% CI 1.24-1.81). Rural adolescents' PA did not differ from urban dwellers'. CONCLUSIONS: Rural environments support PA in children but not that of adolescents. Town and fringe areas with mixed elements of rural and urban land use appear to facilitate and sustain PA in both children and adolescents.