I’ve had several bouts of heart flutters/racing heart while on the bike over the years (I’m 47 by the way). Never been able to get an official diagnosis but all signs point to SVT (including and EKG where the machine said I had SVT but the doctor didn’t see it on the graph so they would give an official diagnosis). Over many years and much experimentation, here are some things I’ve discovered and what has/hasn’t worked for me (hope this is helpful):
- Fasted rides - I just can’t do anything above 70-75% for long periods if I’m fasted. Below sweet spot, I’m ok. At sweet spot, I might get through the workout without an episode, I might not. Above sweet spot, yeah, I’ll be cutting that ride short when my heart rate spikes 15 minutes into the workout. So anything above recovery and I always make sure I have something in my stomach, even if it’s small.
- Caffeine - I’ve been a caffeine addict for as long as I can remember and have been trying to cut back but haven’t give it up all together. For me, what I’ve found is with one cup of coffee, I’ll probably be ok. Two cups of coffee, I’m playing with fire a bit. Three cups of coffee, it’s not a matter of if I’ll have an episode, but how soon into the workout. So I try to limit myself to one cup pre-workout.
- Alcohol - Drinking the night before a morning workout is almost always going to trigger the SVT. And drinking in the evening after coffee in the morning (pretty much my first 6 months of the pandemic), I was having 3-4 episodes per week.
- Some other things I’ve found that help…adding an electrolyte tab to my water seems to do better for me than just plain water. For some reason, going out with just water has resulted in more heart episodes than when I add an electrolyte. Rest…I have kids that until recently, never slept through the night. So I’m was going on 7 years of horrible sleep. Now that they’re sleeping, and I’m sleeping, I seem to have fewer bouts of the SVT.
Sorry for this being so wordy but these are all things I’ve noticed over the year and what I’ve done to keep my SVT in check and keep myself riding. I’ve made peace with the fact that it’s going to happen sometimes and when it does, I try not to get too upset about it and remind myself that it’s better to cut my ride short today and try again tomorrow.
Hope some of this is helpful. Happy riding!!