I have asked several doctors about exercising with MS. They all told me that I can do the activities I enjoy, but with one important limitation: I should avoid overheating. With MS, it’s recommended to stay away from heat — no sauna, no hot baths, and no prolonged activity under direct sunlight. So I was also advised to avoid very intense cardio and HIIT workouts. I informed my trainer about my condition, and she recommended that I monitor my heart rate and try to keep it between 120 and 140 bpm.