It is not easy....
High dopamine tends to induce psychosis up to very worrying levels.
Recreational drugs tend to enhance dopamine production and are enhanced by high dopamine.
For a subject suffering from high dopamine the use of recreational drugs leads generally to unpleasant outcomes because of psychotic behavior or insurgence of psychosis that may even trigger mental illness as schizophrenia and such.
Recreational drugs are not all the same, opiates are very calming in their effects and I may guess that very calming effect responsible to counteract the psychotic one (ever tried opiates with LSD, especially if the trip gets a bit "out of control"?).
Neurotransmitters anomalies are not all the same either.
For example a friend of mine is schizophrenic to the point is on constant medications, even a short walk may trigger unpleasant symptoms, smoking pot for him is a no no thing....but when a schizophrenia attack comes a couple of beers do have a very calming effect on him, even better than valium and he uses beer as a medicament in fact.
It should make no sense because alcohol is known to exacerbate dopamine far more than a short walk but for him it doesn't works that way (schizophrenia is not just high dopamine anyway).
Another friend of mine is a maniac depressive, neurotransmitters are involved here too, he smokes dope as there is no tomorrow and even beer is not an issue for him.
It's tricky.
Slightly higher than normal dopamine tends to push individuals towards recreational drugs because the reward is much greater than for "normal" individuals but higher dopamine levels will scare away from most recreational drugs because the psychotic effects they will trigger.
In other words I suspect anyone here has to find out what works and what doesn't for himself since we are all different.
The advise would be to not underestimate the psychotic effects of certain substances or behaviors (like exercising in your case) because there might be a possibility to not "come back" and having to deal with a mental condition for the rest or great part of life.
Another weird case: a friend of mine, a recreational drugs user (mainly pot) apparently without any issue, once took some LSD (it wasn't the first time by any means), everything as usual but he didn't come back.
He remained in a tripping status as under the LSD effect for years until one day he snorted some cocaine for the first time (I am talking about a long time ago, the '70s, when cocaine wasn't very common at all in the hippies communities, at least here).
Immediately after snorting cocaine he suddenly come back from that LSD trip that lasted maybe 10 years or so.
He became a cocaine addict for quite a few years after that but it is another story....