A new study published in medical journal The Lancet has claimed that sedentary lifestyles and a lack of physical exercise are responsible for 5.3 million deaths - just as many as smoking - throughout the world.

Among the conclusions of the report is that the problem has become so widespread that it should be treated as a pandemic, with physical inactivity said to be the "fourth leading cause of death worldwide".

The report states: "Although evidence for the benefits of physical activity for health has been available since the 1950s, promotion to improve the health of populations has lagged in relation to the available evidence.

"Promotion of exercise has only recently developed an identifiable infrastructure, including efforts in planning, policy, leadership and advocacy, workforce training and development, and monitoring and surveillance.

"The reasons for this late start are myriad, multi-factorial and complex. This infrastructure should continue to be formed, intersectoral approaches are essential to advance, and advocacy remains a key pillar.

"Although there is a need to build global capacity based on the present foundations, a systems approach that focuses on populations and the complex interactions among the correlates of physical inactivity, rather than solely a behavioural science approach focusing on individuals, is the way forward to increase physical activity worldwide."

Commenting the findings, David Stalker, CEO, FIA said: "The statistics reported by the researchers are certainly shocking but should not come as a surprise; the link between health and physical activity is well established.

"As a sector we have always tried to promote positive message about benefits of being active however, this research recommends that warnings about the health risks of inactivity may be more effective as a public health message.

"It is encouraging that the researchers recommend that governments need to do more to raise awareness and help people to get active. The FIA will continue to work in partnership with the Government, the medical community and other sectors to promote the need to engage in regular physical activity."

In 2010, the FIA established the Joint Consultative Forum (JCF) to increase communication between the physical activity sector and the medical community and to encourage the use of physical activity as a routine tool in the prevention and management of chronic disease.

The publication of The Lancet report is timed to coincide with final preparations for the 2012 Olympic Games, with Lord Krebs, chair of the House of Lords' Science and Technology Select Committee (STSC), criticising the legacy plans of the Games.

Speaking on BBC Radio 4's Today programme, Krebs said the government had no credible plan to produce a health legacy from the Olympics and described sport minister Hugh Robertson as being "disinterested" in the issue.

He added that the STSC's report on sport and exercise science - published on the same day as The Lancet report (click here to read more) - revealed that none of the 48 London GP practices surveyed were aware of the latest Physical Activity Guidelines.

Click here for the full report from The Lancet.