Dutch teenagers estimate they sit down for over 10 hours a day, according to research from the public health institute RIVM.

Lessons, doing homework, playing on computers or using a tablet have all contributed to the sedentary lifestyle of Dutch 12 to 20-year-olds, the RIVM said in a new report on Monday.

The research is based on 9,000 people’s own estimates of how often they sit and what other activities make up their day.

On average, the Dutch sit down for 8.7 hours a day, with four to 12-year-olds spending more time on their feet than any other age group. The over-65s sit down for an average of 7.5 hours a day.

Sitting for too long has been associated with an increased risk of obesity, type 2 diabetes and early death, even among people who exercise regularly, the RIVM said.