Markus V. Nahas, Mauro V. G. de Barros, Maria Alice A. de Assis, Pedro C. Hallal, Alex A. Florindo and Lisandra Konrad
A cross-cultural, randomized study was proposed to observe the effects of a school-based intervention designed to promote physical activity and healthy eating among high school students in 2 cities from different regions in Brazil: Recife and Florianopolis. The objective of this article is to describe the methodology and subjects enrolled in the project.
Ten schools from each region were matched and randomized into intervention and control conditions. A questionnaire and anthropometry were used to collect data in the first and last month of the 2006 school year. The sample (n = 2155 at baseline; 55.7% females; 49.1% in the experimental group) included students 15 to 24 years, attending nighttime classes. The intervention focused on simple environmental/organizational changes, diet and physical activity education, and personnel training.
The central aspects of the intervention have been implemented in all 10 intervention schools. Problems during the intervention included teachers’ strikes in both sites and lack of involvement of the canteen owners in schools.
The Saude na Boa study provides evidence that public high schools in Brazil represent an important environment for health promotion. Its design and simple measurements increase the chances of it being sustained and disseminated to similar schools in Brazil.
Humberto José Gomes Silva, Lars Bo Andersen, Mara Cristina Lofrano-Prado, Mauro V.G. Barros, Ismael Fortes Freitas Jr., James Hill and Wagner Luiz do Prado
It is unclear how different exercise intensities affect cardiovascular disease (CVD) risk factors in obese adolescents. The aim of this study was to compare the effects of high-intensity (HIT) vs. low-intensity (LIT) aerobic training on CVD risk factors in obese adolescents.
Forty-three obese adolescents (age: 15.7 ± 1.3 years, BMI: 34.3 ± 4.1kg/m2) participated this study either HIT (corresponding to ventilatory threshold I; N = 20) or LIT (20% below ventilatory threshold I; N = 23) for 12 weeks. All sessions were isocaloric (350 kcal). All participants received the same nutritional, psychological, and clinical counseling. Subjects were assessed in fatness, fitness, lipid profile, and glucose at baseline and after 12 weeks. The CVD risk factors assessed were waist circumference (WC), total cholesterol (TC), high-density lipoprotein (HDL), glucose, and fitness, which were single and clustered analyzed (z scores sum).
Body mass, Body Mass Index, fatness, and WC were improved (P < .001) in both groups. The sum of z scores (WC + TC + glucose-fitness-HDL) improved in both HIT (12 weeks = −2.16 SD; Cohen’s d = .45) and LIT (12 weeks = −2.13 SD; Cohen’s d = .60) without groups differences. Changes in fitness were associated with changes in WC (r = −.48; P = .003).
HIT does not promote any additional improvements in CVD risk factors than LIT in obese adolescents.