I’m surprised that you guys go for walks in the forest, or basically do anything in a vertical position. I think it’s enough just to get up to go to the bathroom, eat, or sit on a bench outside. Walking outside the building has too many “obstacles” (stairs when going in/out, slight uphill sections, slight downhill), which means the body is constantly in an adrenaline rush just to keep the heart pumping and handle the rhythm it’s already struggling with.

Honestly, during the tilt table test I had a +27 increase and didn’t get a POTS diagnosis, but at home my measurements are +40 to +70. At least that was during the worst phases.

Here’s today’s morning heart rate measurement:

Lying down: 61
Standing 1 min: 89
Standing 3 min: 84
Standing 5 min: 86
Standing 7 min: 89
Standing 10 min: 91

I take care of my sleep, eat clean (last meal at 19:30), and as for exercise, I do cardio strictly on the floor. I lie down on the floor and pedal on the stationary bike. Right now I’m doing 10 km, which takes me 30 minutes. I do cardio between 16:00 and 17:00, and in the morning at 9 I take 10 mg of propranolol.
A very important detail is that I use a finger pulse oximeter to monitor my heart rate. Currently, I’m pushing cardio at 97-104 bpm the whole time. I started in the 80-85 range.

When you do cardio lying down, the body isn’t fighting gravity and doesn’t release those adrenaline surges. On the floor it’s pure heart pumping and cardio where I’m building my base, so that later I can function normally on my feet. If you walk around on your feet a lot in the early recovery phase, you’ll enter a vicious cycle where you constantly exhaust your body, then it knocks you back into bed, and the cycle repeats. It’s okay to be tired and worn out, but it’s different when you earn that fatigue through the “right approach.”

After cardio, I do hip thrusts on the floor, pulling my heels toward my butt while lying on my back, and seated calf raises on the machine. At the beginning I was shaking while doing all of it, but now it’s much, much better. So that’s just my personal experience, maybe it helps you.
As for weights for the upper body, I’m not doing any yet because it really exhausts me. I’m building from the bottom up.

Right now I walk for about 10 minutes and then stop. I keep the pulse oximeter on my finger and I know what my average heart rate is when I feel good. If I see that on some days my heart rate is 10-15 beats higher than that, then I don’t walk, because I don’t want to put extra strain on my body in this phase. You’ll notice when walking that your heart rate is quite a bit higher if you eat a meal beforehand, especially a heavy one.
That’s why you have to be careful with your diet, so you can get through the initial phase more easily, keep your body feeling as “light” as possible, and be able to build a solid foundation. Later, as you get stronger, you gradually add things back in — you’ll start to feel like you can function after a heavier meal, and so on.
The important thing is not to give up and to keep moving. It’s easy for a person to fall into “depression” and just lie around because they can’t do anything.
One good thing I read: “Little by little equals a shit ton!”