The survey found there is now a wider belief by GPs that exercise therapy can be beneficial.
Three years ago, 41% thought it was "effective or very effective", rising to 61% now.
But half of the GPs questioned did not have access to an exercise referral scheme. Two thirds of these doctors said they wished they had.
More patients are also interested in how exercise can help them - one in six GPs say they have noticed an increase in the number of people asking whether exercise could help them.
