• Research Review
• Journal Review

Authors: R Guthold, M Cowan, C Autenrieth, L Kann, L Riley

Reference: J Pediatr 2010; published online 22 March 2010
http://www.jpeds.com/article/S0022-3476%2810%2900034-X/abstract

Reviewer: Robert Goldberg, PhD, Contributing editor, ProCor; Professor of Medicine and Epidemiology, Division of Cardiovascular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA

Reviewer comments: Physical inactivity is an important risk factor for many chronic diseases and all-cause mortality which also affects one's quality of life and other important health related outcomes. Adoption of positive lifestyle practices, including regular sustained physical activity, at a young age is of considerable importance both for the prevention of important CHD risk factors and CHD later in life as well as for the maintenance of regular activity habits throughout the adult years.

The results of the present study are disappointing in that the majority of school-aged boys and girls surveyed failed to meet generally recommended guidelines for physical activity. The failure to meet currently recommended levels of physical activity was observed in each of the countries studied, reinforcing the universality of this prevalent and increasing public health problem. Prevalence rates of sedentary activity were especially problematic in young girls.

Considerable work needs to be done to improve the cardiovascular health status of individuals of all ages throughout the world, with one of the most important practices being the adoption of regular activity habits. The results of the present study reinforce this notion by demonstrating that adolescents in the countries surveyed have less than desirable levels of physical activity. These data reinforce the importance of school and community-based interventions that will increase levels of physical activity, and decrease sedentary behavior, in adolescent boys and girls. These efforts need to be potentially age and sex dependent, and culturally appropriate, and much could be learned from questioning the boys and girls themselves as to what they think would encourage them to be less sedentary and more active; these responses would be extremely helpful for designing acceptable programs and outlets for physical activity and for making these activities fun.

This is clearly an area where boys and girls have gotten away from their "roots". More efforts and reminders from other family members and their teachers are needed for adolescents to understand the emotional and physiological benefits that can be gained from participation in regular activity so that the "fruits of their labor" can be reaped in the later years of life.

Purpose of study: To describe and compare levels of physical activity and sedentary behavior in school-aged boys and girls from 34 countries throughout the world.

Location of study: Geneva, Switzerland.

Study Design: Cross-sectional.

Results: Data from the Global School-Based Student Health Survey (GSHS) were used in the present investigation. This self-administered survey, which was developed by the WHO in 2001, was completed by a total of 72,845 school children aged 13-15 years from 34 countries over the period 2003-2007; the majority, but not all, of the countries included in the GSHS obtained nationally representative samples of their target population. The countries were wide ranging including 11 countries in Africa, 11 countries in South America, seven in the Eastern Mediterranean region, and the remainder from Southeast Asia and the Western Pacific.

The questionnaire used in this study was administered during regular school hours and five questions pertaining to overall physical activity, sedentary behavior, and active transportation to and from school were asked. All questions had multiple choice options, were translated into the appropriate languages, and were pilot tested for student comprehension.

The overall survey questionnaire response rate was very good averaging approximately 84%. The percentage of boys in the final sample ranged from 40-60% and the average age of respondents ranged from 13.5-14.4 years.

Across all countries, most school children did not partake in an adequate amount of physical activity. Less than one quarter of the boys and approximately 15% of the girls engaged in physical activity for at least one hour daily on at least five days per week. These percentages ranged widely between participating countries and, in all countries with the exception of Zambia, girls reported being less active than boys.

With regards to walking or riding a bike to and from school, the percentage of boys and girls engaging in this activity ranged widely from 23% (Cayman Islands) to 83% (China) among the boys and from a low of 11% (United Arab Emirates) to a high of 86% (China) in girls. In approximately one third of the countries surveyed, less than one half of the boys rode a bike or walked to school whereas this was the situation in approximately one half of the countries included for girls.

Similarly, the frequency of spending three or more hours during a typical day either sitting and watching television or playing computer video games ranged widely. These estimates ranged from a low of 13% to 58% in boys and from 8% to 64% in girls. In most countries, the prevalence estimates for time spent in sedentary activity was similar for boys and girls.