Improvements on Cardiovascular Diseases Risk Factors in Obese Adolescents: A Randomized Exercise Intervention Study.

BACKGROUND: 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. METHODS: Forty-three obese adolescents (age: 15.7 ± 1.3 years, BMI: 34.3 ± 4.1 kg/m(2)) 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). RESULTS: 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). CONCLUSION: HIT does not promote any additional improvements in CVD risk factors than LIT in obese adolescents.

Atividade física habitual de crianças e adolescentes mensurada por pedômetro e sua relação com índices nutricionais / Usual physical activity in children and adolescents measured by pedometer and its association with nutritional indicators

A monitoração dos níveis de prática de atividade física em segmentos da população jovem tem se tornado importante tema de interesse entre especialistas da área. O Objetivo do estudo foi verificar o nível de atividade física de escolares, baseando-se em duas recomendações vigentes, e analisar a existência de associações entre a quantidadede passos/dia e diferentes indicadores de adiposidade corporal. A casuística foi composta por 162 indivíduos de dez a 18 anos (65 do sexo masculino e 97 do sexo feminino). Foram calculados o Índice de Massa Corporal e o percentual de gordura por impedância bioelétrica. O nível de atividade física habitual foi mensurado por meio de ?pedômetro? (NewLifestyles modelo NL-2000) e analisado de acordo com duas recomendações internacionais: Duncan et al. (masculino: 16.000 passos/dia e feminino: 13.000 passos/dia) e Tudor-Locke et al. (masculino: 15.000 passos/dia e feminino: 12.000 passos/dia). O teste t de Student e a ANOVA One-Away (Post Hoc ? LSD) compararam os grupos formados. O nível de significância adotado foi de 5% (p£0,05). Dos resultados, apenas 18,5% da amostra cumpriu as recomendações propostas por Duncan e 25,9% cumpriram os pontos de corte propostospor Tudor-Locke et al.. Os adolescentes que não cumpriram as recomendações propostas por Duncan et al., apresentaram valores percentuais de gordura corporal maiores quando comparados aos jovens que cumpriram (p<0,05). Pode-se concluir que uma elevada taxa dejovens não cumpriu as duas recomendações analisadas, bem como, apenas um indicador de adiposidade associou-se com o cumprimento de umas das recomendações.

Monitoring physical activity levels in segments of the young population has become an important topic among specialists. The objective of this study was to analyze the physical activity level of schoolchildren based on two current recommendations and to examine the association between the number of steps/day and different indicators of adiposity. The sample consisted of 162 subjects aged 10 to 18 years (65 boys and 97 girls). Body mass index and body fat percentage were calculated. The level of physical activity was quantified with a pedometer (New LifestylesNL-2000) based on the following recommendations: Duncan et al. (male: 16,000 steps/day and female: 13,000 steps/day) and Tudor-Locke et al. (male: 15,000 steps/day and female: 12,000 steps/day). The Student t-test and one-way ANOVA (LSD post hoc test) were used forcomparison between groups. A level of significance of 5% was adopted (p £ 0.05). Only 18.5% of the sample met the recommendations proposed by Duncan et al. and 25.9% met the cutoff proposed by Tudor-Locke et al. Adolescents who did not meet the cutoff proposed by Duncan had higher body fat percentages than those who did (p < 0.05). In conclusion, a high rate of the youngsters did not meet the recommendations analyzed and only one indicator of adiposity was associated with meeting one of the recommendations