[ytoawwhra92]

I hope your doctors clear you for exercise again and you feel comfortable giving it another go (after sufficient rest and recovery from this experience).

I had a similar - but less extreme - experience in my early 30s when I decided to start exercising after 20+ years of highly sedentary living. I somehow convinced myself that my heart rate being >160 while in "zone 2" was normal for me. In truth, what seemed like impossibly light exercise (5-10 minutes of "zone 2" every day) was too intense for me at the time. I burned out after about two months. It was very humbling to realise that the elderly people who jogged in the park near my apartment were more physically fit than me, and it took me a while to accept that.

When I eventually started exercising again I began with an intensity roughly equivalent to walking on a flat surface (HR around 105-115bpm) and stuck to a simple rule of thumb: if I didn't feel fully recovered 15 minutes after finishing a workout I had pushed myself too hard. From that baseline I was able to occasionally do a more intense effort, paying close attention to my heart rate during the workout, and being very mindful of what my body felt like during the effort as well as 15 minutes after, later that day, and the next morning. Over time I was able to ratchet up the intensity of 2-3 efforts per week and still feel fully recovered. After about a year I could do 3-4 genuinely hard workouts a week with a low risk of overtraining or burnout.

What I would point out is that in your original comment you said:

> I started running and cycling. Very short distances, very slowly and very gradually.

So from your perspective these were appropriate efforts. But then you go on to say:

> It made me feel horrible. Each time it would take me a few days to recover, feeling dizzy and mentally exhausted.

> A light jog would make my heart rate climb to 190 bpm immediately. A small couple of percent incline on a bicycle, straight to 190 bpm. Obviously feeling horrible afterwards.

These are really strong indicators that you were pushing far too hard.

That a light jog would be far too hard for a 34 year old is very confronting. It's a huge blow to the ego. I've been there, and worked my way out of the hole. Assuming there's no underlying medical condition I think you can too.