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.     

Pontificating the relationship between parenting styles and academic performance of senior high school students in the Kumasi Metropolis,Ghana

Educational Research for Policy and Practice - The study analysed the relationship between parenting styles and academic performance of senior high school students in the Kumasi Metropolis....     

Educational expansion in Ghana: Economic assumptions and expectations

The neo-classical ‘human capital theory’ continues to be invoked as part of the rationale for educational expansion in the developing world. While the theory provides a route from educational inputs to economic outputs in terms of increased incomes and standards of living, the route is contingent and relies upon a number of key assumptions. This study examines these assumptions alongside student expectations of their educations in the context of Ghana using data collected from a survey conducted at higher education institution and from the Ghana Statistical Service's ongoing living standards surveys. Data indicate that students have high economic expectations but that trends in wages and employment are leading to ‘wage compression’ which may ultimately make expectations difficult to fulfill. The relatively low private costs of education, particularly higher education, may mean, however, that educational investment remains very much a ‘rational’ choice in economic terms. However, the study finds that key assumptions of successful human capital investment went largely unsatisfied in Ghana.     

Executive functioning and preschoolers' understanding of false beliefs, false photographs, and false signs

Two studies were conducted to investigate the specificity of the relationship between preschoolers' emerging executive functioning skills and false belief understanding. Study 1 ( N =44) showed that 3- to 5-year-olds' performance on an executive functioning task that required selective suppression of actions predicted performance on false belief tasks, but not on false photograph tasks. Study 2 ( N =54) replicated the finding from Study 1 and showed that performance on the executive functioning task also predicted 3- to 5-year-olds' performance on false sign tasks. These findings show that executive functioning is required to reason only about representations that are intended to reflect a true state of affairs. Results are discussed with respect to theories of preschoolers' theory-of-mind development.