Fifteen medical organisations in Scotland have called for radical action to improve levels of physical activity.
Physicians, surgeons, psychiatrists, dentists, anaesthetists and GPs joined together as the Scottish Academy of Medical Royal Colleges and Faculties.
They said as much effort should be made to increase activity as was already put into encouraging people to stop smoking or drinking.
A sedentary lifestyle is now recognised as one of the world's biggest killers.
It plays a role in more than 40 major diseases.
"Conservative estimates state that more than 2,500 Scots per year die due to inactivity," said Ian Ritchie, chair of the Scottish Academy.
Mr Ritchie, who is also president of the Royal College of Surgeons of Edinburgh, said: "Scotland's life expectancy is the lowest in Western Europe.
"Physical inactivity, obesity, smoking and alcohol excess cause quarter of all deaths and the evidence about the scale of the problem of physical inactivity cannot be ignored.
"Even this month a major European study concluded that twice as many people die each year due to inactivity than from obesity."
Successive Scottish governments have tried to improve activity levels and Scotland is one of the few nations where surveys have suggested people are taking slightly more exercise.
However, a third of adults still do not exercise for the recommended 150 minutes a week and one quarter of children do not get the recommended one hour a day.
The academy has called for initiatives to tackle inactivity to become part of the core business of the NHS.
It has recommended:
- questions about physical activity levels be included alongside those about smoking and alcohol in all medical admission to hospital forms.
- hospitals have clear walking routes and find ways to encourage staff and patients to get fit.
- GPs give patients as much advice about activity as they currently do about smoking or alcohol.
- all medical students should be taught about physical activity.
"Imagine what an outcry there would be if medical students were not taught about high blood pressure, yet in some medical schools they're not being taught about inactivity," said Dr Andrew Murray, from the Royal College of Physicians and Surgeons of Glasgow.
"This report contains common sense, cost effective, concrete recommendations.
"Many of our patients are surprised given the health benefits that these actions are not already happening routinely."
In an unusual move, the academy has also suggested that a video about inactivity, which has already had almost five million hits on YouTube, be played in waiting rooms.
The Scottish Academy of Medical Royal Colleges and Faculties brings together specialists in emergency medicine, dentistry, anaesthetics, obstetrics, psychiatry, radiology, paediatrics as well as public health and surgery.
The Scottish government welcomed the report.
"All clinicians have the knowledge and skills to promote health as well as to treat illness, and they should be raising lifestyle risk factors, such as physical inactivity, with patients," said Scotland's acting Chief Medical Officer, Aileen Keel.
"It is a myth to say that it takes more than a couple of minutes to do this in a consultation, and the impact of a doctor raising these issues, as the evidence shows, can be very powerful.
"The Scottish government recognises that increasing physical activity levels in Scotland is a top health priority. We need the help of doctors and other health care professionals to get this on the public's agenda."