As the Olympics gets under way, they say much more emphasis should be given to teaching medical student about how exercise can prevent - and even help treat - chronic diseases including diabetes, heart disease and cancer.
Dr Richard Weiler, a consultant in sports and exercise medicine at University College London NHS Foundation Trust, and colleagues found only half of Britain’s 31 medical schools taught students about current physical activity guidance from the Chief Medical Officer.
Five did not include specific teaching on exercise in their undergraduate courses at all, according to results published in the British Journal of Sports Medicine.
On average, students spent 109 hours learning about pharmacology - but a "negligible" 4.2 on physical activity.
Dr Weiler said: “This is lunacy. We throw money at teaching them about drugs but not about how to prevent and treat chronic disease through exercise.”
He added: “I’m sure there are an awful lot of doctors out there that don’t know that many forms of cancer are lifestyle related, and that physical activity reduces your chances of developing them, and improves your outcomes if you do.”
Writing in the journal, he and colleagues warned there was “widespread omission” of teaching about exercise and how doctors could imaginatively encourage people to be more active, rather than brow-beat them.
Dr Weiler said there was far too much focus on treating, rather than preventing, disease, arguing: “We need to put the health back into the National Health Service.”
Many medical school curriculum directors were hospital specialists whose careers had perhaps led them to overlook the importance of lifestyle, he said.
“With all this talk of Olympic legacy, it would be a quick win for Medical Education England to ensure physical activity was part of the curriculum,” he said.
Britain was getting fatter as a nation, causing a growth in lifestyle diseases like diabetes, he said.
“We can’t afford to keep on going as we are. We know that lack of physical activity is one of the major causes of chronic disease - if not the major cause. It's crazy doctors aren't being taught this.”
He said people were wrong to assume that doctors could not get patients to change their lifestyles.
"Research shows you can change behaviour, if you employ the right techniques - which need to be taught.
"Besides doing nothing, finger-wagging is the worst thing doctors can do. They should be helping people to realise they can increase how active they are, and do so in ways they find enjoyable."
Doctors have set up a website, Move Eat Treat, to raise signatures for a Number 10 petition so that "health professionals receive considerable education on lifestyle advice throughout their careers".