This paper examines the costs and benefits of early specialization in sport from a skill acquisition perspective. The focus is on whether early specialization in a single sport is the best way to facilitate the acquisition of skill in that sport. The paper is organized relative to the two major conceptual frameworks that have motivated much of the discussion about early specialization in sport: the theory of deliberate practice and the Developmental Model of Sport Participation. Our analysis reveals that while early specialization in sport is one way to reach elite status, it is not the only way. Considerable evidence shows that many elite athletes specialized in their sport late, following diversified experiences with other sports. These findings raise a number of exciting questions about the long-term development of skill in sport.
David I. Anderson and Anthony M. Mayo
Mary O. Hearst, John R. Sirard, Leslie Lytle, Donald R. Dengel and David Berrigan
The association of physical activity (PA), measured 3 ways, and biomarkers were compared in a sample of adolescents.
PA data were collected on 2 cohorts of adolescents (N = 700) in the Twin Cities, Minnesota, 2007–2008. PA was measured using 2 survey questions [Modified Activity Questionnaire (MAQ)], the 3-Day Physical Activity Recall (3DPAR), and accelerometers. Biomarkers included systolic (SBP) and diastolic blood pressure (DBP), lipids, percent body fat (%BF), and body mass index (BMI) percentile. Bivariate relationships among PA measures and biomarkers were examined followed by generalized estimating equations for multivariate analysis.
The 3 measures were significantly correlated with each other (r = .22–.36, P < .001). Controlling for study, puberty, age, and gender, all 3 PA measures were associated with %BF (MAQ = −1.93, P < .001; 3DPAR = −1.64, P < .001; accelerometer = −1.06, P = .001). The MAQ and accelerometers were negatively associated with BMI percentile. None of the 3 PA measures were significantly associated with SBP or lipids. The percentage of adolescents meeting the national PA recommendations varied by instrument.
All 3 instruments demonstrated consistent findings when estimating associations with %BF, but were different for prevalence estimates. Researchers must carefully consider the intended use of PA data when choosing a measurement instrument.
Alan Nevill, Paul Donnelly, Simon Shibli, Charlie Foster and Marie Murphy
The association between health and deprivation is of serious concern to many health promotion agencies. The purpose of the current study was to assess whether modifiable behaviors of physical activity (PA), sports participation, diet, smoking and body mass index (BMI) can help to explain these inequalities in a sample of 4653 respondents from Northern Ireland.
The study is based on a cross-sectional survey of Northern Irish adults. Responses to a self-rated health question were dichotomized and binary logistic regression was used to identify the health inequalities between areas of high, middle or low deprivation. These differences were further adjusted for other sociodemographic factors and subsequently for various modifiable behaviors of PA, sports participation, diet, smoking, and BMI.
Respondents from high and middle areas of deprivation are more likely to report poorer health. As soon as sociodemographic factors and other modifiable behaviors were included, these inequalities either disappeared or were greatly reduced.
Many inequalities in health in NI can be explained by the respondents’ sociodemographic characteristics that can be further explained by introducing information about respondents who meet the recommended PA guidelines, play sport, eat 5 portions of fruit and vegetables, and maintain an optimal BMI.
Ben Ewald, John Attia and Patrick McElduff
Although an overall public health target of 10,000 steps per day has been advocated, the dose–response relationship for each health benefit of physical activity may differ.
A representative community sample of 2458 Australian residents aged 55–85 wore a pedometer for a week in 2005–2007 and completed a health assessment. Age-standardized steps per day were compared with multiple markers of health using locally weighted regression to produce smoothed dose–response curves and then to select the steps per day matching 60% or 80% of the range in each health marker.
There is a linear relationship between activity level and markers of inflammation throughout the range of steps per day; this is also true for BMI in women and high density lipoprotein in men. For other markers, including waist:hip ratio, fasting glucose, depression, and SF-36 scores, the benefit of physical activity is mostly in the lower half of the distribution.
Older adults have no plateau in the curve for some health outcomes, even beyond 12,000 steps per day. For other markers, however, there is a threshold effect, indicating that most of the benefit is achieved by 8000 steps per day, supporting this as a suitable public health target for older adults.
Tiago V. Barreira, Catrine Tudor-Locke, Catherine M. Champagne, Stephanie T. Broyles, William D. Johnson and Peter T. Katzmarzyk
The purpose of this study was to compare steps/day detected by the YAMAX SW-200 pedometer versus the Actigraph GT3X accelerometer in free-living adults.
Daily YAMAX and GT3X steps were collected from a sample of 23 overweight and obese participants (78% female; age = 52.6 ± 8.4 yr.; BMI = 31.0 ± 3.7 m·kg-2). Because a pedometer is more likely to be used in a community-based intervention program, it was used as the standard for comparison. Percent difference (PD) and absolute percent difference (APD) were calculated to examine between-instrument agreement. In addition, days were categorized based on PD: a) under-counting (> −10 PD), b) acceptable counting (−10 to 10 PD), and c) over-counting (> 10 PD).
The YAMAX and GT3X detected 8,025 ± 3,967 and 7131 ± 3066 steps/day, respectively, and the outputs were highly correlated (r = .87). Average PD was −3.1% ± 30.7% and average APD was 23.9% ± 19.4%. Relative to the YAMAX, 53% of the days detected by the GT3X were classified as under-counting, 25% acceptable counting, and 23% over-counting.
Although the output of these 2 instruments is highly correlated, caution is advised when directly comparing or using their output interchangeably.
Amanda Sonnega, Amanda Leggett, Renee Pepin and Shervin Assari
al., 2010 ; Tang & Sanborn, 2014 ). Given the relatively small and restricted samples of these studies, however, they have limited generalizability to U.S. adults. Relatively few studies have reported on national-level data—and only two in the United States—to explore the effects of physical activity on
Alessandra Prioreschi and Lisa K. Micklesfield
= 119) were recruited from the Chris Hani Baragwanath Academic Hospital (which is the largest public hospital in South Africa and is thus likely to provide a sample of participants that are representative of the Soweto community) for this cross-sectional study completed at the South African Medical
Jeff McNamee and Hans van der Mars
Danielle Symons Downs
Research examining the determinants of exercise motivation among ethnically diverse women is scant. The purpose of this study was to examine the predictive utility of the theories of reasoned action and planned behavior (TRA/TPB) for explaining exercise intention among postpartum women and to examine the moderating influence of ethnicity. Participants were 63 low-income postpartum women (n = 16 white, 47 non-white) who completed self-reported measures of their exercise attitude, subjective norm, perceived behavioral control (PBC), and intention. Hierarchical regression analyses indicated that (a) attitude (β = .59, p < .05) and subjective norm (β = .29, p < .001) explained 66% of the variance in intention, (b) PBC (β = .03, p > .05) was not a significant predictor, and (c) the contributions of the theory constructs predicting intention were not moderated by ethnicity. The study findings provide preliminary support for the utility of the TRA as a framework for understanding exercise intention among ethnically diverse postpartum women. The lack of predictive support for TPB may be due to ethnic/cultural differences or methodological limitations with PBC; however, future research is needed to test this assumption.
Charles F. Morgan, Thomas L. McKenzie, James F. Sallis, Shelia L. Broyles, Michelle M. Zive and Philip R. Nader
We examined associations of demographic/biological, psychological, social, and environmental variables with two different measures (self-reported and accelerometer) of physical activity (PA) in Mexican-American (56 boys; 64 girls) and European-American (49 boys; 45 girls) children (mean age = 12.1 years). Among 32 potential correlates, 4 gender and 16 ethnic differences were found. Percent of variance explained from 3% to 24% for self-reported PA and from 7% to 16% for accelerometer-measured PA. Physical self-perception was the only variable with a significant association across all subgroups and both measures. Less favorable levels of psychosocial variables among Mexican-Americans may explain ethnic differences in PA.