Intensity of exercise recovery,blood lactate disappearance,and subsequent swimming performance

Abstract

The aim of this study was to examine the effects of active versus passive recovery on blood lactate disappearance and subsequent maximal performance in competitive swimmers. Fourteen male swimmers from the University of Virginia swim team (mean age 20.3 years, s = 4.1; stature 1.85 m, s = 2.2; body mass 81.1 kg, s = 5.6) completed a lactate profiling session during which the speed at the lactate threshold (V_LT), the speed at 50% of the lactate threshold (V_LT.5), and the speed at 150% of the lactate threshold (V_LT1.5) were determined. Participants also completed four randomly assigned experimental sessions that consisted of a 200-yard maximal-effort swim followed by 10 min of recovery (passive, V_LT.5, V_LT, V_LT1.5) and a subsequent 200-yard maximal effort swim. All active recovery sessions resulted in greater lactate disappearance than passive recovery (P < 0.0001 for all comparisons), with the greatest lactate disappearance associated with recovery at V_LT (P = 0.006 and 0.007 vs. V_LT.5 and V_LT1.5 respectively) [blood lactate disappearance was 2.1 mmol · l^?1 (s = 2.0), 6.0 mmol · l^?1 (s = 2.6), 8.5 mmol · l^?1 (s = 1.8), and 6.1 mmol · l^?1 (s = 2.5) for passive, V_LT.5, V_LT, and V_LT1.5 respectively]. Active recovery at V_LT and V_LT1.5 resulted in faster performance on time trial 2 than passive recovery (P = 0.005 and 0.03 respectively); however, only active recovery at V_LT resulted in improved performance on time trial 2 (TT₂) relative to time trial 1 (TT₁) [TT₂?TT₁: passive +1.32 s (s = 0.64), V_LT.5+1.01 s (s = 0.53), V_LT?1.67 s (s = 0.26), V_LT1.5?0.07 s (s = 0.51); P < 0.0001 for V_LT). In conclusion, active recovery at the speed associated with the lactate threshold resulted in the greatest lactate disappearance and in improved subsequent performance in all 14 swimmers. Our results suggest that coaches should consider incorporating recovery at the speed at the lactate threshold during competition and perhaps during hard training sessions.     

Child Sleep and Socioeconomic Context in the Development of Cognitive Abilities in Early Childhood

Despite a robust literature examining the association between sleep problems and cognitive abilities in childhood, little is known about this association in toddlerhood, a period of rapid cognitive development. The present study examined the association between various sleep problems, using actigraphy, and performance on a standardized test of cognitive abilities, longitudinally across three ages (30, 36, and 42 months) in a large sample of toddlers (N = 493). Results revealed a between-subject effect in which the children who had more delayed sleep schedules on average also showed poorer cognitive abilities on average but did not support a within-subjects effect. Results also showed that delayed sleep explains part of the association between family socioeconomic context and child cognitive abilities.     

The Delhi dilemma: media representation of the 2010 Commonwealth Games

Developing nations increasingly use sporting mega-events to demonstrate capacity, staking a claim to a place on the ‘world map’ by participating in what has been referred to as the ‘global circus’, or alternatively, the ‘prestige model’. The 2010 Commonwealth Games, hosted by India, provide an example of a mega-event which had mixed results in terms of signalling global modernity. This study extends existing media analysis research that found that the Western media’s interpretation of the event was critical overall and employed negative stereotypes that served to undermine India’s status as a modern power. This study employed a comprehensive textual analysis of relevant articles from eight major daily newspapers to reveal that the Australian print media coverage often focused on the inadequacies of India as an appropriate host nation for the Commonwealth Games.     

Barriers to participation and retention: engaging and returning ‘out of school’ children in the Gambia

This study explores the phenomenon of out-of-school children in the Gambia through the perspectives of children and families. Using mixed methods, the study reports the extent of school participation. Interviews with urban and rural out-of-school children reveal their experiences and reasons for non-enrolment or leaving school. The study highlights children's and families' views about the value of and aspiration for education, so often missed through statistical studies on access to education. Findings suggest the main barriers to participation and retention are a mix of family and school-based factors encompassing issues of affordability and accessibility of school, and family and cultural circumstances. In the context of wider policy reforms, initiatives to address unaffordable costs of school and to improve the quality of education such as the School Improvement Grant and Early Childhood Development provision show promise for engaging and returning children to school.     

Children's Teaching Skills: The Role of Theory of Mind and Executive Function

ABSTRACT— Teaching others effectively may rely on knowledge about the mind as well as self-control processes. The goal of this investigation was to explore the role of theory of mind (ToM) and executive function (EF) in children's developing teaching skills. Children 3.5–5.5 years of age ( N = 82) were asked to teach a confederate learner how to play a board game and were administered multitask batteries of ToM and EF with mental age, sex, and memory capacity as controls. There was a developmental increase in children's teaching skills (e.g., older children taught longer, explained more rules, and used more strategies when teaching). Examined separately, both ToM and EF explained unique variance in teaching skills over and above controls. Taken together, EF was a significant predictor of teaching efficacy over and above ToM and controls, whereas the same did not hold true for ToM. These results suggest that ToM may be a necessary prerequisite for teaching to occur; however, EF skills appear to play a vital role in children's teaching efficacy.