QUESTION FOR ALL YOU ATHLETES ?

Not really answering your question, (I expect Fergus will). I don't condisder myself to be an athlete but I run a marathon a year, plus shorter races, I also go for multiday long distance walks. I cannot imagine doing it on a low carb diet, in fact for the walks (20-30km a day) I end up eating more carbs and reducing my insulin by about 50%.
I'm aiming to do a 1400km walk (2-3months) in the near future and really cannot envisage doing it on a low carb diet

I'll try.

I run the Edinburgh marathon but didn't attempt my first one until after I'd changed my diet to low-carb. I was very anxious about the dietary advice commonly given because I thought it would have made it much more difficult for me to control my blood sugars due to the extra carbs and insulin. Yet all the advice seemed to suggest it couldn't/shouldn't be done any other way. So I did it on a low-carb diet.
It went very well, I tested my BS at halfway and took 1 dextrosol tab every 2 miles on the way back. BG 4.8 at the finish!
The interesting thing was that I didn't hit 'the wall', and actually got a wee bit quicker over the last few miles. It got me thinking that perhaps hitting the wall, and carbo loading beforehand weren't entirely unconnected.
2007 my wife did the marathon too. She's not diabetic, but she ate as I ate throught her training for the race. She didn't hit the wall either.

Entirely anectdotal of course, but I proved to myself that carbo loading was at least unnecessary, and at worst possibly counterproductive. I favour the long distance cycling events these days, but the principles are no different. Carbs and insulin are low, dextrosol in my back pocket just in case, and no shortage of energy.

I put it down, at least in part, to the more efficient functioning of fatty acid metabolism is the absence of excess insulin.

I hope that helps but PM me by all means.

All the best,

fergus

I'm too old, too overweight and too unfit for Marathons, but I do walk a lot, including some tough ones. I do this in the morning and never have a high carb breakfast. I don't use insulin or any insulin stimulating medication,( just 2 or 3 x Metformin 500 per day) but it is possible to run out of fuel. I have done it occasionally. I simply carry a pack of gluco-tabs in my pocket. In fact they live in the pocket of my Craghoppers. I rarely need them. The current pack has only 2 missing.

Not marathons, but
I play tennis for 1½ - 2 hours at a level where I soon warm up even in icy weather. I normally begin within an hour of a reduced carb meal. I sometimes have a dried apricot (4 g carb) between sets. I don't run out of energy. I also do an hour in the gym just on water.