If all of my general health assessments indicate i'm healthy, but i'm still having exercise intolerance, what type of doctor do you recommend seeing?

A psychologist: may be able to help you understand why you are having difficulty with exercising if all of your objective testing and evaluations are normal.

Primary care: A good medical checkup through a medical doctor is likely a good place to start. From there specialists could potentially be brought in based upon the likely cause. Cardiac screening with a stress test and/or an echocardiogram can be a consideration if it is felt it could be cardiac related.