Exercise can be as addictive as heroin



Exerceise 'junkies' have the same withdrawal symptoms as heroin addicts when they try to stop, a study has shown.

Being weaned from physical activity produces the trembling, teeth chattering and drooping eyelids exhibited by drug addicts who go cold turkey, researchers said.

Obsessive exercising to shed weight can lead to the potentially fatal condition anorexia athletica, they added.



Obsessive: Scientists have found that that exercise can become addictive just like drugs

The report by neuroscientists from Tufts University in Boston suggests that as soft drugs can lead to hard drugs, so mild exercise such as jogging or bike riding can turn into triathlons and 100-mile bike rides.

In the journal Behavioural Neuroscience, they wrote: 'Excessive running shares similarities with drug-taking behaviour.



'As with food intake and other parts of life, moderation seems to be the key.'

The scientists studied rats split into two groups - one group given exercise wheels.

The rats were then given naloxone, which heroin addicts take to produce immediate withdrawal symptoms.

They said because the active rats' symptoms were worse, it appeared they had undergone the same changes in the brain as drug-addicted rats.