Respiratory responses and rating of perceived exertion of severely obese adolescents during continuous and intermittent graded walking protocols: Application to cardiorespiratory field tests.

During 20 m shuttle tests, obese adolescents may have difficulty achieving maximum cardiorespiratory performance due to the presence of braking-relaunch phases (BRP). Nineteen obese adolescents aged 15.2 ± 1.5 years (body mass index [BMI] = 39.7 ± 5.9 kg.m-2) performed three graded walking exercises on a 50 m track at speeds between 3 and 6 km/h: a continuous-straight-line protocol (C), a continuous protocol that required turning back every 30 sec (C-BRP) and an intermittent protocol that consisted of successively walking then resting for 15 sec (15-15). Oxygen uptake (VO2), aerobic cost of walking (Cw), ventilation (VE) and rating of perceived exertion (RPE) were measured at each stage during the protocols. During C-BRP, the responses were not significantly higher compared with C (p > 0.30). During 15-15, the VO2, Cw and VE were ~ 15 to 25% lower than during C beginning at 4 km/h (p < 0.05). In obese adolescents, the respiratory impact of sudden directional changes during the 20 m shuttle-type test appeared to be minor at walking speeds. During the 15-15 test, the intensity increases more progressively, and this design may encourage obese adolescents to walk further than during a continuous test.

[Factors associated with eating disorders in students of the University of Littoral Côte d'Opale]. / Facteurs associés à la suspicion de troubles du comportement alimentaire chez des étudiants de l'Université du Littoral Côte d'Opale.

AIMS: Our study aimed to observe the rate of eating disorders in first year public health students (allied medical and sports) of the University of the Littoral Opal Coast (ULCO) using the SCOFF-F (Sick, Control, One, stone, Fat, Food; French version) questionnaire and to compare morphological characteristics, level of physical condition, level of physical activity and sleep quality. METHODS: Overall 642 subjects (459 women and 183 men) aged 22years (20.9±4.9years) participated in this study (Universanté-CEMHaVi). Weight, height, and fat mass were measured, and waist-to-hip ratio and body mass index (BMI) were calculated. The level of physical condition was evaluated using several physical tests: Leger and Boucher (20m) and shuttle run (4×10m), Sargent-test and handgrip strength. The SCOFF-F questionnaire followed by a clinical maintenance conducted by a professional was used to detect eating disorders. Several other questionnaires were used to evaluate the physical activity level; General Practice Assessment Questionnaire (GPAQ) and wellness. Sleep quality index was evaluated using Pittsburgh Sleep Quality Index (PSQI). RESULTS: SCOFF-F was positive in 24.2% of women and 10.2% of men. In women, there were no significant differences between those who had a positive SCOFF-F screening and those who had a negative SCOFF-F screening regarding age, height, waist-to-hip ratio, level of physical condition measured and level of physical activity evaluated. However, significant differences were found between women who had a positive SCOFF-F screening and women who had a negative SCOFF-F screening regarding sleep quality, well-being score, BMI and fat mass. In men, significant differences were found between those who had a positive SCOFF-F screening and those who had a negative SCOFF-F screening regarding BMI and fat mass. CONCLUSION: This study suggests that in both sexes, having a positive SCOFF-F screening is associated with higher BMI. In women, the increase in BMI and the perturbations in sleep quality and well-being score may indicate bulimia nervosa. The definition of a panel of possible factors associated with eating disorders can help in screening and early detection of eating disorders.

DXA-based variables and osteoporotic fractures in Lebanese postmenopausal women.

INTRODUCTION: The aim of this study was to assess DXA-based variables (bone mineral density, bone mineral apparent density, compressive strength index of the femoral neck and trabecular bone score) in Lebanese postmenopausal women having presented a previous fracture. MATERIALS AND METHODS: One thousand Lebanese postmenopausal women between 45 and 89 years participated in this study. The women were recruited by advertisements offering bone mineral density measurements at a reduced cost. Subjects with previous history of radiotherapy or chemotherapy were excluded. Informed written consent was obtained from all the participants. RESULTS: Femoral neck compressive strength index (FN CSI) was significantly (P<0.001) associated with the presence of fracture using a simple logistic regression (odds ratio=0.51 [0.385-0.653]). When a multivariate logistic regression analysis was performed with the presence of fracture as a dependent variable and each of age, FN BMD and FN CSI as independent variables, only FN BMD (P=0.005) and FN CSI (P=0.004) were found to be associated with the presence of fracture. CONCLUSION: This study suggests that FN CSI is associated with history of osteoporotic fractures in postmenopausal women. The use of FN CSI in clinical practice may help to identify patients with high risk of fracture. LEVEL OF EVIDENCE: Epidemiological study, level IV.

Comparison of fat oxidation during exercise in lean and obese pubertal boys: clinical implications.

OBJECTIVE: To examine fat oxidation rates during exercise in lean and obese pubescent children. DESIGN: A graded leg cycle ergometry test was performed by two groups of pubescent boys (13 lean: mean (SD) age 12.0 (0.5) years, body mass index (BMI) 18.56 (1.12) kg/m(2); 17 obese: mean (SD) age 12.1 (0.1) years, BMI 26.68 (3.37) kg/m(2); p<0.001). The first step of the test was fixed at 30 W and power was gradually increased by 20 W every 3.5 min. The mean ventilatory gas measurement was obtained during the last 30 s of each step for calculation of fat oxidation rate vs exercise intensity. RESULTS: At low intensity (0-30% of peak oxygen consumption) when fat-free mass is considered, the fat oxidation rate was identical for the two groups. At higher intensities (40%, 50% and 60% of peak oxygen consumption) the fat oxidation rate was significantly higher in lean boys than in obese boys. CONCLUSION: These results confirm that obese pubertal boys have fat-free mass decreased capacities to use fat during moderate exercise. The findings suggest that obese boys need to practise physical activity at a lower intensity than healthy boys to enhance lipolysis and diminish adipose tissue and the consequences of obesity.

[Treatment of pediatric obesity: effects on body composition and physical fitness]. / Prise en charge ambulatoire de l'obésité: effets sur la composition corporelle et la capacité aérobie.

AIMS: To assess the efficiency of an ambulatory weight management programme of pediatric obesity, including 1 gymnastic session per week, on body composition and physical fitness (max). SUBJECTS: Fifteen adolescents participated in the 9-month intervention. BMI and fitness and physical activity assessed by a questionnaire were evaluated at baseline, and after intervention. RESULTS: Prepubescent subjects (N=6): no significant change of BMI, body composition, nor max. Pubescent subjects: significant decrease of BMI, and z score BMI, and % fat mass, increase of fat free mass. Activity questionnaire: non-significant trend to decreased TV watching, significant increase in practice of physical activity during weekend. CONCLUSION: A modest increase in physical practice, included in the dietary-behavioural management of adolescent obesity, is able to improve overweight and physical fitness.