Evolution of fat oxidation during exercise in obese pubertal boys: Clinical implications

Abstract

In this study, we examined fat oxidation rates during exercise in obese pubescent boys. Three groups of pubescent boys (16 pre-pubescent, Tanner's stage I; 16 pubescent, Tanner's stage III; and 14 post-pubescent, Tanner's stage V) performed a graded test on a leg cycle ergometer. The first step of the test was fixed at 30 W and power was gradually increased by 20 W every 3.5 min. Oxygen consumption ([Vdot]O₂) and carbon dioxide production ([Vdot]CO₂) were determined as the means of measurements during the last 30 s of each step, which allowed us to calculate fat oxidation rates versus exercise intensity. Between 20 and 50% of peak oxygen consumption ([Vdot]O_2peak), fat oxidation rate in relative values (mg · min^?1 · kg FFM^?1) decreased continuously with pubertal development. In the same way, the maximum rate of fat oxidation occurred at a lower percentage of [Vdot]O_2peak (pre-pubescent: 49.47 ± 1.62%; pubescent: 47.43 ± 1.26%; post-pubescent: 45.00 ± 0.97%). Our results confirm that puberty is responsible for a decrease in fat free mass capacities to use fat during exercise. The results suggest that post-pubescent obese boys need to practise physical activity at a lower intensity than pre-pubescent boys to enhance lipolysis and diminish adipose tissue and the consequences of obesity.     

Reading and knowledge transfer in Ghana: the behaviour,attitudes and self-concepts of first-year students in Bachelor of Education programmes

The purpose of this study is twofold. First, it is an attempt to fill in the blanks on the unexplored map of reading behaviours, attitudes, and self-concept of teacher education students in Ghana. Secondly, it investigates whether the negative perceptions of lecturers from the University of Cape Coast (UCC) and the University of Education Winneba (UEW) about their students’ reading attitudes and behaviour correspond to the students’ self-perceptions. We investigated the reading attitudes, behaviour, and self-concept of 316 students from UCC and UEW. Outcomes showed that spending time on reading for enjoyment is not popular amongst students. A surprisingly positive attitude towards reading for school, for enjoyment and self-concept of reading amongst students was found. This is contradictory to the negative perceptions of lecturers at UCC and UEW. The correlations we found between reading behaviour, attitude and self-concept are in line with recent reading research findings.     

ENTRE REPRODUCTION ET MOBILISATION: LES RAPPORTS DE GENRE EN FORMATION CONTINUE EN FRANCE ET AU CANADA

REPRODUCTION OR MOBILISATION? GENDER PROPORTIONS IN CONTINUING EDUCATION IN FRANCE AND CANADA – Initial education provisions for women have evolved greatly over the past 40 years. But what about their situation within adult education and training? This article, comparing Canada and France, shows that, while it is well known that more women than men participate in adult education, their greater presence in professional training courses is a new development. The analysis highlights certain particular findings, such as the growing demand for continuing education in Canada and the increased rate of participation by full-time employees in France. In both countries, a number of social factors continue to influence women’s participation.