I'm interested in how we can maximise restoring energy stores (mainly glycogen, but I'm deliberately being vague) either between closely spaced rides or on long rides.
I ask in the context of a couple of tough rides at the weekend: Friday 277 km solo into a serious headwind, Sunday 324 km with a group (they were all stronger than me and some of them were better rested; we had a bit of a headwind at times but not severe). In between was a rest day, and a well-fed one at that.
I got to a stage on Sunday's ride where I was clearly running on pretty much empty: even gentle climbs were almost impossible, and a snack of 100–200 kcal of mostly carbs would perk me up for a few minutes, starting a few minutes after I ate it but then it would wear off. A meal of several hundred kcal (again lots of carbs) with a bit of sitting around had a similar effect but lasted a little longer. I'd obviously overdone it: still depleted from Friday ride, trying to keep up with a fast group in the morning and missing a planned stop due to torrential rain, and nowhere open to have a food break out of the weather. This also meant I ran out of pocket snacks (at least those compatible with rain gear) towards the end and had to stop to get food out of a pannier.
There's literature on refilling glycogen stores over a period of several hours (example paper) but not much about shorter timescales, and how do we translate this to a post-bonk situation when you need to carry on against the clock? Is it better to have a long break, (perhaps eat, rest, eat again, go), or is it better to try to keep stuffing the carbs in while going along slowly? Is there a difference if there's a known hilly stretch?
This is related to my old question Fuelling multi-day riding (carb loading/replacement) but this time I'm thinking of what to do when reserves are gone mid-ride – the multi-day aspect of last weekend is more like background, so this is about a much faster timescale.