The influence of a 6.5% carbohydrate-electrolyte solution on performance of prolonged intermittent high-intensity running at 30°C

Nine male student games players consumed either flavoured water (0.1 g carbohydrate, Na⁺ 6 mmol · l^?1), a solution containing 6.5% carbohydrate-electrolytes (6.5 g carbohydrate, Na⁺ 21 mmol · l^?1) or a taste placebo (Na⁺ 2 mmol · l^?1) during an intermittent shuttle test performed on three separate occasions at an ambient temperature of 30°C (dry bulb). The test involved five 15-min sets of repeated cycles of walking and variable speed running, each separated by a 4-min rest (part A of the test), followed by 60 s run/60 s rest until exhaustion (part B of the test). The participants drank 6.5 ml · kg^?1 of fluid as a bolus just before exercise and thereafter 4.5 ml · kg^?1 during every exercise set and rest period (19 min). There was a trial order effect. The total distance completed by the participants was greater in trial 3 (8441 ± 873 m) than in trial 1 (6839 ± 512, P < 0.05). This represented a 19% improvement in exercise capacity. However, the trials were performed in a random counterbalanced order and the participants completed 8634 ± 653 m, 7786 ± 741 m and 7099 ± 647 m in the flavoured water (FW), placebo (P) and carbohydrate-electrolyte (CE) trials, respectively (P = 0.08). Sprint performance was not different between the trials but was impaired over time (FW vs P vs CE: set 1, 2.41 ± 0.02 vs 2.39 ± 0.03 vs 2.39 ± 0.03 s; end set, 2.46 ± 0.03 vs 2.47 ± 0.03 vs 2.47 ± 0.02 s; main

effect time, P < 0.01). The rate of rise in rectal temperature was greater in the carbohydrate-electrolyte trial (rise in rectal temperature/duration of trial, °C · h^?1; FW vs CE, P < 0.05; P vs CE, N.S.). Blood glucose concentrations were higher in the carbohydrate-electrolyte than in the other two trials (FW vs P vs CE: rest, 4.4 ± 0.1 vs 4.3 ± 0.1 vs 4.2 ± 0.1 mmol · l^?1; end of exercise, 5.4 ± 0.3 vs 6.4 ± 0.6 vs 7.2 ± 0.5 mmol · l^?1; main effect trial, P < 0.05; main effect time, P < 0.01). Plasma free fatty acid concentrations at the end of exercise were lower in the carbohydrate-electrolyte trial than in the other two trials (FW vs P vs CE: 0.57 ± 0.08 vs 0.53 ± 0.11 vs 0.29 ± 0.04 mmol · l^?1; interaction, P < 0.01). The correlation between the rate of rise in rectal temperature (°C · h^?1) and the distance completed was ?0.91, ?0.92 and ?0.96 in the flavoured water, placebo and carbohydrate-electrolyte conditions, respectively (P < 0.01). Heart rate, blood pressure, plasma ammonia, blood lactate, plasma volume and rate of perceived exertion were not different between the three fluid trials. Although drinking the carbohydrate-electrolyte solution induced greater metabolic changes than the flavoured water and placebo solutions, it is unlikely that in these unacclimated males carbohydrate availability was a limiting factor in the performance of intermittent running in hot environmental conditions.     

The Use of Research to Improve Professional Practice: a systematic review of the literature

In a keynote address to the Teacher Training Agency Annual Conference, Professor David Hargreaves suggested that teaching could become an evidence-based profession if educational researchers were made more accountable to teachers. This systematic literature review set out to explore: how teachers use research; which features of research encourage teachers to use research findings in their own practice; whether medical practitioners make greater use of research findings than teachers; and approaches to dissemination. Two key ideas emerge from this review. First, there appear to be common barriers to research use in both medicine and in education. Findings suggest that there is a need to create a culture in the public sector which supports and values research. There are, however, a number of factors, which appear to be more specific to the education field. Key differences in the way that research knowledge is constructed in the social sciences has led to researchers being challenged about their findings, particularly in relation to the context, generalisability and validity of the research. For these reasons the development of communication networks, links between researchers and practitioners, and greater involvement of practitioners in the research process, have emerged as strategies for improving research impact.     

EVALUATING COMPENSATORY EDUCATION: OVER WHAT PERIOD OF TIME SHOULD ACHIEVEMENT BE MEASURED?

An assumption fundamental to compensatory education is that greater achievement can change the academic future of disadvantaged students, which may in turn enhance their "life chances." Therefore, one of the goals of compensatory education is to increase the achievement of disadvantaged students. To change students' futures, this increase in achievement should be evident subsequent to participation in a compensatory-education program. At a minimum, an increase in achievement should persist over the summer following a school-year program. Evaluations of compensatory education in general, however, and of Title I of the Elementary and Secondary Education Act (ESEA) in particular, have not included measures of sustained achievement. Instead, judgments of program success have been based on students' achievement during the school year: that is, on a spring posttest score adjusted in some way for the preceding fall pretest score.