Exercise should be considered a risk factor for medical problems, so should be included along with temperature, blood pressure, pulse and respiratory rate as one of the key indicators of health, Khan and colleagues from the U.S. and Australia write in a paper published in The Lancet on Thursday.
"Exercise might also be considered as a fifth vital sign and should be recorded in patients' electronic medical records and routine histories," says the paper, titled Sport and Exercise as Contributors to the Health of Nations.
In an interview with CBC News shortly before the paper's release, Dr. Khan, a professor in the school of kinesiology at the University of British Columbia, said doctors can be key motivators in getting people active, and can help them put together an easy plan to fit in exercise.
"Doctors are one element of getting people on a physical activity plan, but patients listen to doctors," he said. At the same time, "family doctors understand physical activity has a very powerful health benefit, but [people] don’t know how to fit it in. ... simple things like walking instead of taking transit, and walking the dog make a big difference."
In their paper, Khan and his colleagues say lack of inactivity is good reason for "evidence-based therapy."
"Physicians and other health professionals can contribute substantially to patients' adoption of exercise behaviours, just as they have provided smoking cessation advice and contribute to smoking reduction in many countries," their paper says.
"A straightforward but influential step forward would be measurement of the exercise vital sign in every consultation. Patients ought to report how many minutes of physical activity they undertake in an average day and how many days a week such activity takes place. This measurement provides a score (in minutes per week) that can alert patients and clinicians to potential risks related to physical inactivity."
Low fitness 'a predictor of mortality'
Countries bidding to host the Olympics usually claim such high-profile sporting events will promote public health, but whether they in fact translate into an upswing in physical activity is uncertain, says the paper, which examines the broader question of whether sport and exercise contribute to the health of countries.
It notes that data on participation in sports are too scarce to conclude sport and exercise contribute to a country's health, but there's strong evidence that regular participation in sports and/or exercise clearly benefits both physical and mental health, "and that health professionals need to pay more attention to their patients’ fitness."
The paper also gives examples of how sports participation, in particular, has been shown to have far-reaching health benefits.
For instance, a series of small randomized clinical trials published in 2010 showed people who took up playing football two or three times a week experienced reduced risk factors for cardiovascular disease, diabetes and the brittle-bone disease osteoporosis.
In the CBC interview, Khan emphasized how sport can also have a positive effect on health awareness. He noted that The Lancet paper points out FIFA’s 11 for Health education program, in which soccer stars such as Cameroon’s Samuel Eto’o provide educational messages about health issues for young people, resulted in an 18 per cent improvement in health knowledge in schools in Zimbabwe and Mauritius.
The paper concludes that the evidence for physical activity as a major public health preventive approach and "a potent medical therapy" has increased exponentially in the 64 years since London last hosted the Olympics.
"We believe that small changes at the community level and large, nationwide policies and initiatives are needed to improve health at a country level.”