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

Gautier Zunquin  Denis Theunynck  Bruno Sesboüé  Pierre Arhan  Dominique Bouglé 《Journal of sports sciences》2013,31(4):315-318

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.  相似文献   

Haemodynamic changes after prolonged water immersion     

Alain Boussuges  Laurent Mourot  Yves Jammes  Bruno Melin  Jacques Regnard 《Journal of sports sciences》2013,31(6):641-649

Abstract

Thermoneutral water immersion increases cardiac preload and changes the neuroendocrine settings of blood volume regulation. The resulting marked diuresis may lead to significant haemodynamic changes after the end of a prolonged water immersion. Ten volunteers underwent 6 h of complete thermoneutral water immersion. Changes in cardiovascular status were assessed 1 h and 16 h after water immersion. Haemodynamic changes were assessed by Doppler echocardiography. Arterial wall distensibility was estimated by pulse wave velocity analysis. One hour after water immersion, mean weight loss was 1.78 kg and urine volume amounted to 1.5 litres. Echocardiographic measurements evidenced a significant decrease in dimensions of the left cardiac chambers and inferior vena cava. The decreased cardiac preload was paralleled by a lower stroke volume and cardiac output. A peripheral vasoconstriction associated with a relative decrease in the lower limb blood flow was evidenced by an increase in carotid-pedal pulse wave velocity and by a decrease in ankle brachial index. Sixteen hours after water immersion, cardiac preload and cardiac output remained below baseline values and peripheral vascular tone was still higher than at baseline. Marked haemodynamic changes had not returned to baseline 16 h after water immersion. There is a need to design fluid-replacement protocols to improve this recovery.  相似文献   

Incumbent actors,guided search paths,and landmark projects in infra-system transitions: Re-thinking Strategic Niche Management with a case study of French tramway diffusion (1971–2016)     

Bruno Turnheim  Frank W. Geels 《Research Policy》2019,48(6):1412-1428

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Metacognitive learning strategies: differential development patterns in high school     

Bruno Leutwyler 《Metacognition and Learning》2009,4(2):111-123

The main objective of this study is to identify the development of students’ self-reported use of metacognitive learning strategies during high school. Therefore, the study analyses the differential development patterns of 1,432 students, between grade 10 and 12, in a longitudinal sample. The results suggest that, from a global perspective, there is no development of students’ self-reported use of metacognitive learning strategies during high school. The expected gender-specific differences in favour of female students are replicated in this sample. However, the self-reported use of monitoring and evaluation strategies tends to converge between genders during high school, whereas the differences in the self-reported use of planning strategies remain stable. The consequences for the understanding of metacognitive development are discussed.  相似文献   

Neuromuscular adaptations to sixteen weeks of whole-body high-intensity interval training compared to ergometer-based interval and continuous training     

Gustavo Zaccaria Schaun  Stephanie Santana Pinto  Bruno Brasil  Gabriela Neves Nunes  Cristine Lima Alberton 《Journal of sports sciences》2019,37(14):1561-1569

The neuromuscular adaptations between ergometer-based high-intensity interval training (HIIT-T; n = 15), whole-body high-intensity interval training (HIIT-WB; n = 12) and moderate-intensity continuous training (MICT; n = 14) were compared in forty-one healthy men randomized to 16 weeks of training (3x per week). Two-way repeated measures analysis of variance (ANOVA) showed countermovement (CMJ) and squat (SJ) jump height (HIIT-T: 8.5 ± 13.3%; 3.1 ± 9.7%, HIIT-WB: 6.4 ± 9.8%, 10.4 ± 16.1% and MICT: 2.2 ± 9.5%; 4.4 ± 12.1%, respectively), SJ peak power (HIIT-T: 1.7 ± 3.9%; HIIT-WB : 6.4 ± 7.9%; MICT: 0.5 ± 6.5%) and CMJ rate of force development (HIIT-T: 58.1 ± 50.5%; HIIT-WB: 36.9 ± 54.2%; MICT: 38.4 ± 64.3%) improved similarly in all training groups (all p < 0.05). CMJ peak power increased only after HIIT-T (4.3 ± 5.5%) and HIIT-WB (4.5 ± 5.2%), while no differences were observed in both the rectus femoris and vastus lateralis maximal electromyographic amplitude. Finally, marked improvements were also observed in the number of repetitions in the HIIT-WB protocol at the eighth week, with no further improvement at the sixteenth week. These data suggest that 16 weeks of HIIT-WB is capable to improve neuromuscular function to a similar extent as HIIT-T and MICT.  相似文献   

Determination of a quantitative parameter to evaluate swimming technique based on the maximal tethered swimming test     

Rafael Soncin  Bruno Mezêncio  Jacielle Carolina Ferreira  Sara Andrade Rodrigues  Rudolf Huebner  Julio Cerca Serrão 《Sports biomechanics / International Society of Biomechanics in Sports》2017,16(2):248-257

The aim of this study was to propose a new force parameter, associated with swimmers’ technique and performance. Twelve swimmers performed five repetitions of 25 m sprint crawl and a tethered swimming test with maximal effort. The parameters calculated were: the mean swimming velocity for crawl sprint, the mean propulsive force of the tethered swimming test as well as an oscillation parameter calculated from force fluctuation. The oscillation parameter evaluates the force variation around the mean force during the tethered test as a measure of swimming technique. Two parameters showed significant correlations with swimming velocity: the mean force during the tethered swimming (r = 0.85) and the product of the mean force square root and the oscillation (r = 0.86). However, the intercept coefficient was significantly different from zero only for the mean force, suggesting that although the correlation coefficient of the parameters was similar, part of the mean velocity magnitude that was not associated with the mean force was associated with the product of the mean force square root and the oscillation. Thus, force fluctuation during tethered swimming can be used as a quantitative index of swimmers’ technique.  相似文献   

The “Indefinite Discipline” of Competitiveness Benchmarking as a Neoliberal Technology of Government     

Bruno  Isabelle 《Minerva》2009,47(3):261-280

Minerva - Working on the assumption that ideas are embedded in socio-technical arrangements which actualize them, this essay sheds light on the way the Open Method of Co-ordination (OMC) achieves...  相似文献   

Toward an understanding of higher-order thinking among minority students     

Eleanor Armour-Thomas  Keith Bruno  Brenda A. Allen 《Psychology in the schools》1992,29(3):273-280

Recent investigations have established the importance of higher-order thinking in the acquisition and application of learning skills in diverse domains of inquiry. Such findings have implications for enhancing the quality of thinking of all children but have particular significance for those minority students who historically have not performed as well as their more economically advantaged peers. Although much has been written about the construct, research is still needed to identify the specific processes underlying higher-order thinking and to examine its use among minority populations. A principal-factors extraction with varimax rotation analysis was used in the present study to clarify the nature and function of higher-order thinking among minority students from economically disadvantaged backgrounds. The results allowed for a specification of the mental processes associated with the construct and the extent to which students reported an awareness and use of these processes in academic problem-solving situations.  相似文献   

Notes of iron in bone-black     

DR. Bruno Terne 《Journal of The Franklin Institute》1892

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Art Markets and Economics: Introduction     

Bruno S. Frey 《Journal of Cultural Economics》1997,21(3):165-173

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