"A sedentary lifestyle has become one of the major public health problems in developed countries", Juan P. Rey-López, lead author of the study and a researcher at the University of Zaragoza (UNIZAR), tells SINC. "During the week, one-third of teenagers said the watched more than two hours of television per day. At weekends, this figure exceeds 60%".
The results, published in the July issue of the journal Preventive Medicine, show that teenagers devote more time to sedentary behaviour (in front of a screen) at the weekend.
The study, which forms part of the European HELENA study, analysed the prevalence of sedentary behaviour in 3,278 adolescents (1,537 boys and 1,741 girls aged between 12.5 and 17.5) in 10 European cities (Athens and Heraklion in Greece, Dortmund in Germany, Ghent in Belgium, Lille in France, Pécs in Hungary, Rome in Italy, Stockholm in Sweden, Vienna in Austria, and Zaragoza in Spain).
The teenagers indicated the amount of time they spent in front of the television, computer and games consoles, the amount of time spent connected to the Internet and the amount of time spent studying (outside school hours). The researchers also studied the availability of computers, televisions and consoles at home and in teenagers' bedrooms, and their impact on whether they watched too much television (more than two hours per day).
"Our findings support the recommendation of the American Academy of Pediatrics not to put televisions in teenagers' bedrooms, in order to (theoretically) reduce the amount of time they spend watching the television", says Rey-López.
Computers in the bedroom, but not televisions
"Having a games console or television in the bedroom triples the risk of exceeding the health recommendations to not spend more than two hours per day watching television. However, having a computer in the bedroom reduces the risk of excessive television watching", the researcher from Aragon explains.
The authors also observed significant differences between the sexes in terms of the amount of time spent on sedentary pastimes. Adolescent girls are more sedentary in terms of the amount of time spent studying and surfing the net, while boys spend more time playing electronic games.
According to a study published last month in the Journal Medicine and Science in Sports and Exercise, there is a strong association in adults (dose-dependent) between the number of hours spent watching television and cardiometabolic health, making it highly recommendable not to watch television to excess during leisure time.
Juan P. Rey-López, Germán Vicente-Rodriguez, Francisco B. Ortega, Jonatan R. Ruiz, David Martinez-Gómez, Stefan De Henauw, Yannis Manios, Denes Molnar, Angela Polito, Maite Verloigne, Manuel J. Castillo, Michael Sjöström, Ilse De Bourdeaudhuij, Luis A. Moreno y en representación del grupo de estudio HELENA. "Comportamientos sedentarios en adolescentes europeos: estudio HELENA". Preventive Medicine 51:50 julio de 2010.
Wijndaele K, Healy GN, Dunstan DW, Barnett AG, Salmon J, Shaw JE, Zimmet PZ, Owen N. "Increased cardiometabolic risk is associated with increased TV viewing time". Medicine and Science in Sports and Exercise; 42(8):1511-8, agosto de 2010.