20% of the population are ‘physically inactive’
MedWire News: One in five adults globally does not meet minimal levels of physical activity necessary for health enhancement, and can therefore be defined as physically inactive, report researchers.
"Physical inactivity is now identified as the fourth leading risk factor for global mortality," explain Samuel Dumith (Federal University of Pelotas, Brazil) and colleagues.
In addition, "physical inactivity levels are rising in many countries with major implications for increases in the prevalence of noncommunicable diseases and the general health of the population worldwide," they say.
To better understand the worldwide prevalence of physical inactivity and assess its association with development level of each country, Durmith and team conducted a pooled analysis of three multicenter studies.
The studies, conducted between 2002 and 2004, investigated the prevalence of physical inactivity in 76 countries, and comprised almost 300,000 individuals aged 15 years or older.
Each study used the International Physical Activity Questionnaire (IPAQ) to assess physical inactivity. This questionnaire looks at physical activity in four domains: work, transportation, home, and leisure time.
The researchers defined physical inactivity as less than 20 minutes per day of vigorous-intensity physical activity on at least 3 days per week, or less than 30 minutes per day of moderate-intensity physical activity on at least 5 days per week.
As reported in the journal Preventive Medicine, the overall worldwide prevalence of physical inactivity was 21.4%, and was higher among women (mean 23.7%) than men (18.9%).
After adjusting the data for the total population of each country, the worldwide prevalence of physical inactivity was 17.4%, with a median of 18.0%.
The researchers observed a weak positive association between the prevalence of physical inactivity and a country's level of development, assessed by the Human Development Index (HDI), which encompasses life expectancy, education, and per capita gross national income.
Indeed, the least developed countries (lowest quartile of the HDI) showed the lowest prevalence of physical inactivity, at 18.7%, whereas the most (highest quartile) developed countries had the highest prevalence of physical inactivity, at 27.8%.
Durmith and co-authors note that the prevalence they report may be underestimated, "because the IPAQ tends to overestimate the physical activity level."
In an accompanying commentary Mathieu Bélanger (Centre de formation médicale du Nouveau-Brunswick, Moncton, Canada) and Charlie Foster (University of Oxford, UK) said "there is a global and urgent need to take action against physical inactivity."
These findings "help build the case for better public health organization and effort to tackle physical inactivity at a worldwide level," they remarked.
MedWire (www.medwire-news.md) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2011
By Laura Dean