ABSTRACT Background: Related to exercise hypothesis, the aim of the present study was to explore the influ- ence of physical activity on asthma and allergic rhini- tis in a developing country where publicity cam- paigns about the benefits of exercise are scarce. Methods: The analysed data were self-reported and obtained through the standardized International Study of Asthma and Allergies in Childhood Phase Three written questionnaires completed by 3026 adolescents 13/14 year old in Skopje (Republic of Macedonia). Vigorous physical activity and televi- sion-watching time—both unadjusted and adjusted for confounding factors—were used as variables for analysis. Odds ratios (OR, 95 % CI) in binary logistic regression were employed for statistic analysis of the data. Results: Vigorous physical activity both  3 times and 1-2 times per week was associated with an in- creased risk of current wheeze (aOR: 1.66; 1.08-2.55; p = 0.020 and aOR: 1.70; 1.23-2.36; p = 0.001, respectively), speech-limiting wheeze (aOR: 3.15; 1.13-8.77; p = 0.028 and aOR: 4.62; 2.22-9.62; p = 0.000, respectively) and exercise-induced wheeze (aOR: 2.72; 1.93-3.83; p = 0.000 and aOR: 4.01; 3.12-5.14; p = 0.000, respectively). Frequent physical activity was positively associated only with current allergic rhinitis symptoms (aOR: 1.40; 1.04-1.90; p = 0.029). Television watching  3 hours a day increased the risk of current wheeze (aOR: 1.34; 1.01-1.77; p = 0.042) and exercise-induced wheeze (aOR: 1.32; 1.05-1.65; p = 0.016). Conclusion: The findings support the aggravating role of sedentary regimen and poor physical fitness on asthma symptoms, but not on allergic rhinitis. Physical activity may trigger asthma symptoms when physical fitness is poor and asthma is not con- trolled. Key words: Adolescent. Allergic rhinitis. Asthma. Physical activity. INTRODUCTION An increase in the prevalence of asthma and aller- gic rhinitis in children and adolescents has been ac- counted in most countries worldwide 1 . On the other hand, modern lifestyle had led to an increased inac- tivity among the population 2 previous to the onset of publicity campaigns about the benefits of exercise. Allergol et Immunopathol 2008;36(5):247-53 ORIGINAL ARTICLES Influence of physical activity and television-watching time on asthma and allergic rhinitis among young adolescents: preventive or aggravating? E. Vlaski a , K. Stavric b , L. Seckova a , M. Kimovska a and R. Isjanovska c a Department of Pulmonology and Allergology. University Children’s Hospital. Skopje. The Republic of Macedonia. b Department of Immunology. University Children’s Hospital. Skopje. The Republic of Macedonia. c Institute of Epidemiology with Biostatistics and Medical Informatics. Skopje. The Republic of Macedonia. Correspondence: Emilija Vlaski, MD, PhD Department of Pulmonology and Allergology University Children’s Hospital, Faculty of Medicine Vodnjanska 17. 1000 Skopje The Republic of Macedonia Tel.: + 389 2 3147475 Fax: + 389 2 3129027 E-mail: vlaskie@sonet.com.mk