[Schiendelman]

No, that would wake you up long before it had cardiovascular benefit. You need your heart rate up into zone 2 to 5 to really have a positive impact. That's 120 BPM plus for most people. Once you're around 80 it'll wake up anyone, even someone with very low cardiovascular fitness.

[econ]

I read with the right dream (nightmare) heart rate can climb to 180.

If you slowly condition yourself I think you can exchange sleep quality for increased heart rate.

But I suspect the heart needs rest too and you will die.

An isometric hold would be better I think. You don't get any vo2max improvement but it does improve cardiovascular health.

[Schiendelman]

That's an interesting idea. Do you know if anyone's tried it?

[econ]

https://news.ycombinator.com/item?id=48755297

[strbean]

> Once you're around 80 it'll wake up anyone

Source? I haven't been able to find info on this. I get resuls on nocturnal tachycardia and such. Nothing on elevating a sleeping person's heart rate and observing the result, though.

[Schiendelman]

To be clear, if you implanted a lead, you might not wake them up. It's the mechanism by which you would raise their heartrate that would wake them - the same things that elevate heartrate from external stimulation would also cause cortical arousal.