Fitness benefit to exercising off vs. on meds?
Hello! New to this sub, so please excuse any obvious faux pas. I've been dealing with dysautonomia, specifically exercise induced tachycardia for about four years. I'm fairly fit trail runner and do usually at least 1-2 50ks a year, typical weekly distance is 25-40 miles. I take 5mg ivabradine BID to control my HR. Even medicated, it will often spike to 180-190 in the first half mile no matter how slow I start out, but doing jumping jacks or something to get my HR up to 85-95 before I start running is typically effective at eliminating the spike. My resting HR is around 58, my avg HR medicated on a run is 140s. VO2max is 46. When I forget to take my med, my avg HR jumps up to the high 150s to 160s. When this happens, my garmin watch registers anaerobic benefit (usually between 1.5-2.5, for those of you that that means anything to).
My question is.....is it some sort of biohack to occasionally train without the medication to get that benefit? Or maybe the better question is, is there a benefit to it at all? I've been cleared physically/anatomically (no coronary issues, normal/low BP, great cholesterol, etc) so my doctor isn't concerned about me running with that unmedicated HR, I just don't usually do it because it makes it harder to keep up with people on group runs, etc. I'm not good about incorporating speedwork, etc. into my training, and I'm wondering if this is a sort of cheat code. Any insight or guidance?