This release is available in French.
Montreal, March 31, 2009 – Although winter's grasp has subsided to spring, its effects could have a long term impact on the exercise patterns of teenagers. According to a five-year study published in the Annals of Epidemiology, while teens are generally more active in warmer months, significant drops in physical activity during winter months contributes to a general slowdown in exercise habits throughout adolescence that could persist over time.
Study investigators – from the Centre de Formation Médicale du Nouveau-Brunswick of the Université de Moncton and Université de Sherbrooke, the Université de Montréal and McGill University – counter that declines in physical activity could be offset by promoting a diversity of physical activities including those that can be enjoyed during winter.
"While physical activity augments in spring and summer, these increases do not compensate for winter drop offs, which contribute to declining physical activity throughout adolescence," says Mathieu Bélanger, lead author of the study, research director at the Centre de formation médicale du Nouveau-Brunswick and epidemiologist at the Centre de recherche Beausejour. "Throughout our five-year study, the average daily number of physical activity sessions among participants decreased by nearly one third. The sharpest declines occurred during the coldest months."
As part of the study, 1293 students initially aged 12 to 13 years were monitored from grade 7 to grade 11. Participants were recruited from 10 schools in the Montreal area and were asked to report involvement in physical activity over different seasons. Results were then compared to weather data from Environment Canada.
"Poor weather is one of the most frequently reported barriers to the practice of physical activity," says Jennifer O'Loughlin a researcher from the Université de Montréal's department of social and preventive medicine Centre Hospitalier de l'Université de Montréal.
"In this study we found weather conditions did affect participation in physical activities, but the effects of climate were very modest, suggesting the impact of seasons on physical activity is not solely related to weather changes," says O'Loughlin.
Bélanger and colleagues hypothesised that weather curtailed spontaneous and unplanned physical activities among teens, since adolescents favour structured activities. What's more, planned activities unfold to preset schedules and are less likely to be cancelled because of inclement weather.
The research team advises that winter activities of all types be promoted to curb drops in physical activity among teens. "We are not advocating that indoor physical activities be preferred to outdoor activities, simply that efforts be made to ensure that a variety of activities be available during winter," cautions Bélanger.
About the study:
"Influence of weather conditions and season on physical activity in adolescents," in the Annals of Epidemiology, was authored by Mathieu Bélanger (Centre de formation médicale du Nouveau-Brunswick, Université de Moncton and Université de Sherbrooke; and Centre de recherche Beauséjour, Regional Health Authority A), Katherine Gray-Donald (McGill University), Jennifer O'Loughlin (Université de Montréal and Centre Hospitalier de l'Université de Montréal), Gilles Paradis (McGill University), and James Hanley (McGill University).
Partners in research:
This study was funded by the Canadian Cancer Society and the Canadian Institutes of Health Research.
On the Web:
About the journal Annals of Epidemiology: http://www.annalsofepidemiology.org/
About the Centre de formation médicale du Nouveau-Brunswick: www.umoncton.ca/medecine
About the Université de Moncton: www.umoncton.ca
About the Université de Sherbrooke: www.usherbrooke.ca
About McGill University: www.mcgill.ca
About the Université de Montréal: www.umontreal.ca
About the Centre Hospitalier de l'Université de Montréal: www.chumtl.qc.ca
To interview Mathieu Bélanger:
Josée Nadeau
Agente de développement
Centre de formation médicale du Nouveau-Brunswick
Telephone: 506-863-2222
Email: josee.p.nadeau@umoncton.ca
To interview Jennifer O'Loughlin:
Sylvain-Jacques Desjardins
International press attaché
Université de Montréal
Telephone:514-343-7593
Email: sylvain-jacques.desjardins@umontreal.ca
Journal
Annals of Epidemiology