Reykjavík teenagers sleep an average of just six hours a night during weekdays, which is far too little sleep. Year 10 students are significantly heavier than the same age group were just 12 years ago.
Last year, 75 percent of Year 10 students at six Reykjavík schools took part in a detailed analysis of their health, fitness, stamina, sleep, academic results and lifestyles. The sample is an equivalent number to ten percent of all Year 10 students in Iceland. A very similar study was also carried out 12 years ago.
University of Iceland sports and health professor Erlingur Jóhannsson told RÚV that the teenagers’ body weight has increased by around four kilograms (8.8 lb.) since 2003. “Their stamina has decreased by a range of eight to ten percent over those twelve years. In relation, the number of overweight individuals has increased considerably compared to 12 years ago. And this is a very ominous development, because we actually thought things were getting better, if anything,” Erlingur says.
While the data do not make clear if the weight gain is due to fat or increased muscle mass, they do show that teens are moving less than they used to, and spending more time sitting still. Erlingur points to many research projects which show that sedentary lifestyles early on have very serious impacts later in life.
Participants wore sensors on their wrists throughout the research, which monitored both their movement and their sleep patterns.
The sensors showed that the teenagers generally go to bed late and sleep little. In fact, the results show that only eight percent of 15-year-old boys get enough sleep, and 13 percent of girls. On average they sleep six hours on school nights, whereas they should have eight hours’ sleep.
Researchers say this is very significant, and that research shows students who sleep so little have trouble concentrating at school and this shows in their results, as well as affecting their mood, and also their mental and physical health.
The same group involved in this research were also studied at the ages of seven and nine, and will be again when they reach 17.
Erlingur Jóhannsson says that the teenagers are being researched more frequently now, “Because life is changing quicker than it used to a few years ago.”