There is certainly the possibility so let's be careful with our assertions.
I, on the other hand, vape before running 10k's weekly. LOVE IT. Seems to help me keep my heart rate lower. Recovery time is lessened and endurance increased. Honestly, I tend to be a bit slower than when not vaped. SO the compromise is a bit of speed. I do it for fun anyway...so no probs
It's also your physical activity!
I flew around the world in first class and sit next to 30 year millionaires with big bellies! I was 40 at the time and way healthier and more fit. Being a cyclist and surfer and a holistic diet was the biggest factor. Now that I have a late on set illness (genetics).
Cannabis is way healthier than the 7 medication drugs the experts gave me.
Cannabis is only good if everything else is in check.
A bad heart is a bad heart.
Lifestyle plays an important part.
Story:
Many years ago when I was 40 I surfed with a 70 year old man in HAWAII 30 foot + waves.
The biggest wave of the day came in and he paddled as fast as he could to catch it. I paddled for safety in the channel. He rode the wave with skill.
Smile from ear to ear. Latter that session he says to me "HEALTH is your WEALTH"! If your not healthy your not wealthy!
Cannabis is the only thing that works for my condition. (I take no drugs)
My assessment is wrong in your eyes and that is fair. I had my heart rate check my last doctor visit and the Nurse said that: "at least your heart is healthy"!
Cannabis is like herbal tea in my eyes.
If someone has a unhealthy heart I believe it's genetics or life style!
Good luck in your race!