[katieHaylor (OP)]

Jason says:

I'm training for a marathon, and like many I'm dreading 'hitting the wall' and have reached it several times during my training, usually at about 18-20 miles. I am curious to know if there is any scientific basis for carb-loading and postponing glycogen depletion? I've read about doing a 'depletion run' and a day of zero carbs followed by 3 days on a carb binge! Any evidence for it?

Have also heard mixed opinions on carb loading and where the carbs go, liver or muscles...


What do you think?

[wolfekeeper]

Yes, science is generally behind the idea that carbohydrate loading before endurance races give positive improvements and can help avoid 'the wall', which happens when your muscles run out of carbohydrates.

https://en.wikipedia.org/wiki/Carbohydrate_loading

Training with depleted carbohydrate stores has a far more mixed experimental evidence for beneficial results. In principle it could uprate enzymes to break down fat stores in some way, but in practice muscles tend to burn carbohydrates together with fat, and one of the results of normal training seems to be that muscles tend to better spare carbohydrates anyway.

https://www.runnersworld.com/nutrition-weight-loss/a20803222/training-with-depleted-carbohydrate-stores/

[diverjohn]

Hello! I've run 8 marathons over the last few years in Canada and USA. I usually start loading up on carbohydrates AND water 2 days before a race. I also avoid added sugar, alcohol, and dairy products in the week before the run. By race day my body has enough fuel to last me 3 hours under good circumstances. To ensure I don't bonk and hit the wall after 30 km I will consume a carbohydrate gel pack (small packet of syrup usually available at the water stations) every 10 km with water.
Every runner has their favorite brand of gel and experienced runners will usually carry several during the run. As for the sports drinks offered, I avoid most of them as I find they are almost always mixed incorrectly and have nearly made me vomit in the first races.
During a marathon run, you'll be losing glucose via muscle activity, but you are also losing water and salt through sweating.
Good luck in your run!

[rami999]

its just practice and low Heart beat rythm

[Colin2B]

its just practice and low Heart beat rythm

No, these have nothing to do with the practice of carb loading which is to do with building up a glycogen store in the muscles and liver.
Please stop making pointless posts.