Professional football players in Scotland will no longer be allowed to head the ball the day before and the day after a match after studies show how it affects the brain.
The link between repetitive heading of a football and brain damage has prompted clubs to limit heading balls in training.
According to a landmark study, former professional football players are three and a half times more likely to suffer from dementia and other neurological diseases.
There will be an immediate ban on exercises with repeated heading of the ball more than once a week and a day before or after a match day.
Scotland was the first European country to ban children under the age of 12 from heading balls in training due to brain damage concerns. Football players in English football were restricted to 10 high-force heads a week in training.
According to the SFA doctor, there is measurable memory impairment lasting 24 to 48 hours after a series of heading, and that brain-related proteins can be found in blood samples for a short time after heading.
Reducing the exposure to heading in training is the goal.
The professional teams in Scotland were consulted before the guidelines were released. Monitoring activity in training is one way clubs are being told to reduce the damage from heading.
The guidelines being introduced were supported by more than 70% of the clubs surveyed.
A report funded by the FA and the Professional Footballers' Association and conducted by the University of Glasgow found that former professionals were more likely to die of Alzheimer's disease than the public.
The study found that the mortality from neurodegenerative disease was higher for former professional soccer players than it was for the Scottish population.
It was not possible to determine if the higher levels of brain disease were due to repeated concussions or something else.
Jeff Astle was found to have died from an industrial disease caused by heading heavy leather footballs when he was 59 years old.
Dawn Astle called the SFA's guidelines a landmark ruling for the dementia in football campaign.