The SARS-CoV-2 pandemic had changed drastically the social life of children and youth, including their ability to adhere the physical activity (PA) recom-mendations. This study highlights the impact of the SARS-CoV-2 lockdown on children’s daily physical activity, sedentary behaviors and sleep duration. It also determined the impact of this specific context on adiposity and cardio-metabolic indicators among children aged from 9 to 12 years old from Con-stantine–Algeria. Children were divided into 2 groups according to the prac-tice of PA, a cross-sectional study was conducted at 2 different times. The first time, was before the SARS-CoV-2 pandemic, where the pre-lockdown lifestyle and PA data were collected via a validated questionnaire. The sec-ond time was during the lockdown, where the same questionnaire was asked to children’s parents via telephonic interviews. A significant decline in the frequencies of PA patterns by 3.8 hours has been observed in the study pop-ulation. In parallel, sedentary behaviors has been significantly increased by 4.5 hours in equal proportions between swimmers and sedentary children per day. Half of the children decreased their night sleep duration by an aver-age of 54 minutes. This new lifestyle context induced by the lockdown was associated with an increase in body weight (3.69±0.9 kg) and body mass in-dex (2.1±0.48 kg/m2) in the whole study population. These results might increase the prevalence of cardio-metabolic complications associated with overweight and obesity observed in the population of children and adoles-cents in Constantine in the near future.