How do I change how often my 2023 apple ultra watch checks my heart rate?

Let me give you a use case so you understand this better: while cycling I come to a short steep slope and want to monitor how much strain it puts on my heart as I ascend it, which my doctor has asked me to monitor, since I'm 60 and working on my cardiovascular conditioning. It doesn't do me any good to know what my heart rate was 5 minutes ago when I was still at the bottom of the slope or after I'm already on level ground again. It regularly shows me my heat rate 5 minutes ago or even 9 minutes ago, rarely 2 minutes ago. Does it even record what the heart rate was between 2 minute checks, or even 5 minute ones so I can access them later? And again, if other sport watches from years ago, which also have dozens of features, can give continuous readings (obviously many think that's useful since they do that), then the much more expensive Ultra should be able to as well. So assuming you are correct about this, it's time to return it.

One additional thing to consider: even a healthy heart beats 60 times a minute (resting) to 120 times a minute (heavy exertion). So if the watch is only measuring the heartbeat every two minutes at best, or even producing an average every two minutes, that misses or obscures so many data points that no one who thought about it would think that was useful data.

I've used Apple products since the days of Mac SE's in the mid-80's, and generally liked them, but I know that their biggest failing is not delivering on basic functionality everyone else has, then stubbornly insisting they are getting it right, even when told for years by everyone that they aren't (think blu-ray).

Thanks! That's the kind of information I was looking for.