Well, merely swishing liquids with carbohydrates around in your mouth and the spitting it out can increase athletic performance in athletic activities lasting over 1 hour!

From https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3916844/ :

> Carbohydrate (CHO) mouth rinse is defined as a CHO fluid distribution around the mouth for 5 to 10 s with subsequent expulsion by spitting. The utilization of either a low-concentrated 6.0% to 6.4% glucose or partially hydrolyzed maltodextrin are the most common CHO used, with the latter being colorless and tasteless when dissolved in water.

...

> CHO mouth rinse seems to improve performance during moderate- to high-intensity exercise (~60% to 75% VO2max), of at least 1 h duration. It is probable that the mechanism involved in this improvement may not be metabolic but neural, via oral CHO receptors (glucose and maltodextrin) that activate brain regions related to the sensation of reward and pleasure.

Note that it apparently isn't taste that is having the effect, as (according to this paper) maltodextrin, when dissolved in water, doesn't have a taste. So apparently there's some mechanism other than either ingestion (metabolic) or taste.

I thought that there had been studies that proved insulin spikes in response to sweet flavors even without caloric content? Not that I have links to them on hand.

Fairly certain I have, at least, seen the headlines.

I meant my last line not as a disputation against, but only as an indicator that I was, at the time, too lazy to provide references.

Ah, yes. Sometimes I'm amused by the expectation of HN readers that anyone commenting will have kept an exhaustive bibliography of everything they've ever read.

:(