A few years back, there were a number of startups that essentially resold prescriptions of the ABT/DXCM CGM and provided personalized meal/exercise-response analytics on top. Seems like traction has been tough going, though. Dialing back from "anyone with potential metabolic issues" -- what's a realistic market? Something like high-level athletes and/or bio-hacker enthusiasts are the only folks who seem to care. On the low end, the OTC options are eating away as well.. they are less accurate, but probably solve the use case better for a pre-diabetic "once-a-year/occasional" wear use case.

Talking to ultramarathoners and cyclists, I think lactate is a biomarker that is tracked (POC blood samples) and would be more immediately useful for training/performance. AID might be construed as a form of doping, IMO.

Yes. But you don't need to monitor glucose levels to do this. Because it's well known you can productively use as much as you could manage to consume (without vomiting). So all the device will ever tell you (if you're in the middle of significant endurance event) is that you need to raise your blood sugar. It'd be no more actionable than a writing 'your blood sugar is low' on your hand with a sharpie.

My understanding is that essentially all high-level endurance athletes are just maximizing their simple sugar intake at all times (during exercise) and knowing blood glucose/ketone levels wouldn't change anything about that intake, nor would it have any impact on crashes.

All high level endurance athletes are on high carb diets all the time and are never anywhere near ketosis (unless something has gone very wrong)