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Time spent in vigorous physical activity is associated with increased exhaled nitric oxide in non-asthmatic adolescents


  • All authors have contributed substantially to the planning and design of the study, data interpretation, writing and critical appraisal of the report and in the decision to submit the manuscript for publication. Christine Sachs-Olsen and Sveinung Berntsen have also been involved in data collection.

  • Ethics

  • The study was approved by the Medical Research Ethics Committee and was performed in accordance with the ethical standards of the 2000 Declaration of Helsinki. Written informed consent was obtained from all participating children and their parents.

  • Conflicts of interest

  • The authors have stated explicitly that there are no conflicts of interest in connection with this article.

  • Present address for Sveinung Berntsen: Department of Public Health, Sport and Nutrition, Faculty of Health and Sport Sciences, University of Agder, Norway

  • The study is performed within the ORAACLE (the Oslo Research group for Asthma and Allergy in Childhood; the Lung and Environment), which is part of the GA2LEN network. GA2LEN is a project of the EU 6th framework programme for research contract no. FOOD-CT-2004–506378.

Christine Sachs-Olsen, MD, Department of Paediatrics, Oslo University Hospital, Rikshospitalet, Pb. 4950 Nydalen, NO-0424, Oslo, Norway. Tel: +47 23070000/+47 99241675, Fax: +47 23072290, email:


Introduction:  Physical activity (PA) is important in preventing disease, but endurance elite athletes have increased prevalence of asthma and airway inflammation.

Objectives:  We aimed to determine if PA was associated with increased fractional exhaled nitric oxide (FENO) in asthmatic and non-asthmatic adolescents.

Methods:  FENO was recorded (Niox Mino®, Aerocrine AB, Stockholm, Sweden) in 169 adolescents (13–14 years) in a nested case–control analysis from the Environment and Childhood Asthma study, Oslo, 92 adolescents with and 77 without asthma. They underwent clinical examination, lung function measurements and treadmill run measuring peak oxygen uptake, and objectively recorded PA for four consecutive days. PA was classified as moderate, vigorous and very vigorous, and total number of hours of each category was recorded for each subject. Associations between FENO and PA were tested using linear robust multiple regression analyses.

Results:  In non-asthmatic adolescents, FENO was associated with daily hours of vigorous to very vigorous (r = 0.27, P = 0.02) and very vigorous PAs (r = 0.25, P = 0.036) in bivariate analyses. In multivariate analyses, FENO was associated with vigorous to very vigorous PA [regression coefficients (95% confidence interval) 1.9 (0.6, 3.1); P = 0.004] and more strongly with very vigorous PA [3.9 (1.5, 6.4); P = 0.002] in non-asthmatic but not in asthmatic adolescents. Total daily PA was not associated with FENO in either group. Thus, 1 h of very vigorous PA per day increased FENO by 3.9 ppb.

Conclusion:  Vigorous to very vigorous PA, contrasting total daily PA, was significantly associated with increased FENO in non-asthmatic adolescents, suggesting that intensive PA may induce airway inflammation independent of asthma.

Please cite this paper as: Sachs-Olsen C, Berntsen S, Lødrup Carlsen K, Anderssen SA, Mowinckel P and Carlsen K-H. Time spent in vigorous physical activity is associated with increased exhaled nitric oxide in non-asthmatic adolescents. Clin Respir J 2013; 7: 64–73.