Anthropometric and Metabolic Changes Associated With a Low-volume Home-based Exercise Program

A randomized clinical trial in the city of Niteroi, Rio de Janeiro, Brazil, was conducted during the school year of 2007 (March to December 2007). The trial had a factorial design based on two different interventions: 1) nutritional counseling and 2) home-based exercise. The present study focused on the effects of exercise intervention.

Of the 36 public schools spread over five different areas, we selected 20 schools from three areas with similar demographic and socio-economic profiles. Because of the small number of male cooks (n=5), we included only women who were neither pregnant nor breastfeeding. Cooks on sick leave or those working in other capacities were excluded. A total of 101 cooks were eligible, and six refused to participate in the study.

All participants received information about the goals of the study and signed a document indicating informed consent. The study was approved by the institutional review board of the State University of Rio de Janeiro.

School cooks enrolled in the present study were public servants and work in periods of eight hours, five days per week, in three different shifts (morning, afternoon and night). They are responsible to prepare all meals served at school and cleaning up, and schools do not have any machine to help them to perform their tasks. They eat at least one meal at school.

Sample size As previously reported13), the sample size was calculated assuming an individual reduction of 10% in sugar consumption (3.4 grams) with a power of 80% and a 5% significance level. Anticipating a rate of participation agreement around 80%, the total sample size was estimated to be 80 school cooks. For this purpose, 20 schools employing a total of 130 school cooks were randomized.