For what it's worth - I'm a firm believer that what is always healthy for your body, is not always healthy for your mind.

Some of the most productive people I know eat nothing but donuts and coffee, and don't exercise at all. They're smart, driven, and highly successful.

Meanwhile, I know a lot of people who put exercise and food as a priority, and don't seem nearly as sharp or as successful. Maybe this all washes out, with age.

Point is - do whatever works for you. Don't let some blog, or some person on the internet, tell you how to perform optimally!

I did see a cardiologist after COVID-19, he did prescribe some medicine to "calm my heart down a bit", I don't meet actual criteria for tachycardia and he agree in the end that I can postpone medicine if I start any aerobic exercise -- which I still didn't, except for VR games, which can be really intense, but alas, I don't have the time for or discipline.