I personally don't exercise, because over-exertion is a trigger, but I have other chronic issues that are irritated by exercise. I would never dissuade someone from exercise! Watch your heart rate and your threshold will be lower that average! Weightlifting was difficult for me and my clusters but you have to learn your own limits, the hard way unfortunately. Please stay active and don't let fear of a cluster keep you from improving yourself, you need this accomplishment to feel good! As long as you enjoy the exercise, do it!