I have a regular workout schedule at the moment, but only when I wake up after 18:00 local, because cycling on the roads in CONUS when there are normal levels of traffic on them is approximately suicidal. I cover myself in EL wire and way too many flashing LEDs and go at like 03:00. I'm also a lights-off midnight console jockey and being outdoors in the mojave during daytime would cause me to immediately burst into flames.

Doesn't seem to have much effect on my sleep, but I also famously ingest way too much caffeine at all hours of the day.

TBH I prefer to be awake when everyone else is asleep. Crowds and lines and traffic are all pretty terrible, but so is living in low-population-density areas without easy access to goods and services. Being nocturnal in an urban environment is the only mitigation I know of. If I could be "cured" I wouldn't want to be.