I think that "carb loading" is overrated for endurance athletes, and although it is probably effective to a degree, it really isn't based on much sound science.

You should take a look at Volek and Phinney's book "The Art and Science of Low Carbohydrate Performance" (or "the art of avoiding the bonk") which promotes ketosis for endurance athletes. The point is that a "keto-adapted" athlete will start a race with much lower muscle glycogen levels (than a "carb loaded" athlete), the rate of glycogen depletion during the race is much lower.

This article talks about a growing "low-carb" contingent in the ultra-marathon community: http://www.meandmydiabetes.com/2012/08/11/western-states-100-low-carber-wins-ultramarathon-steve-phinney-and-jeff-volek-study/

Tim Noakes, author of the running bibe "The Lore of Running" and a previous advocate of carbo-loading has now reversed his position and practices and recommends low-carb for endurance runners: http://www.runnersworld.co.za/nutrition/novel-dietary-ideas/

My daughter who is paleo (age 14) does not 'carb load' or do anything different for her soccer games or for practice. She doesn't understand the people who say they are 'carb loading' when she just goes about her day the same with or without soccer. It doesn't affect her performance.

She told me the other day that she doesn't feel the need to drink water during games either. Said her urine is light colored so she feels she is hydrated. Now, if she was practicing in Arizona I would be worried. She eats and drinks when she feels she needs to. Plain and simple.

I am wondering about the 'carb loading' (for athletics) idea actually, which brought me to your question. Perhaps being Paleo helps so you don't have to 'carb load', just a theory. Any input is appreciated.

I switched from a primarily diet where my carbo loading was achieved primarily through grain-based foods to paleo with zero grain-based foods. I do endurance mountain biking so there is also a lot of eating while riding. The Paleo for Athletes allows grain-based carbs during some window before, during and after exercise but I find that I don't need it. My carbo loading consists of lots of mellons, bananas, nuts (fat loading?) and things like honey, agave and molasses.

For anything under 2.5 hours, I'm taking in a variety of simple sugars and electrolytes while riding. Up to six hours, I add BCAA and a small amount of real food like bananas, honey, nuts, figs and dates. Beyond that, or for multi-day events, I'm adding a little bit of protein powder to my honey.

The biggest challenge for me was not carbos but electrolytes. I never paid much attention to it before, but it seems require supplementation here in Texas.

I ran my last marathon with no carb-loading, and went just paleo weeks before. During race, I took some CLIF bars on mile 8 and some gu every 2-3 miles. I had to walk from mile 18, but that was due to my running mechanics, not nutrition. I had stiff calves/cramps, but was not exhausted, bonked, or anything. See here

I actually came to paleo because of the failure of a high carb diet for my endurance exercise. I was a long distance hiker. Two years in a row I hiked the Pacific Crest Trail. I hiked 20-35 miles every day on a high sugar, high processed, high starch backpacker's diet. At the end of this my metabolism was totally hosed. I literally had to eat any time the trail was level or downhill. I popped candy and cookies all day long. I was always hungry. After the hike, despite not eating a lot, I could not keep the weight off and I could not exercise without triggering massive hunger.

Eventually I found low carb paleo. My first backpacking trip after adjusting to the diet I was able to break trail in fresh snow all day long without tiring and without eating. I slept on snow with only a 3/8" foam pad. I was cold, but I was able to keep myself warm because I was able to access my body fat for heat as well as energy. It was an epiphany.

I continue to hike and backpack. Sometimes I go for day hikes without any breakfast and it's not a problem. I've recently started running. Yesterday I set off for a run without breakfast and without bringing any water. I ran for 3 hours. I was hungry at the start and then I could feel a switch turn within me and the hunger went away. I had steady energy and a positive, happy mood the entire time. I got a bit thirsty toward the end, though. It was around 90 degrees and I was in the noonday sun.

I will NEVER go back to my previous high carb ways.

I competed in Ironman races for 10 years but had to stop recently due to heart arrhythmia. Those were not related to structural damage to my heart but I still stopped racing a year ago and focused on getting healthy. As you can imagine I had training days where I consumed a month-worth of carbohydrates in a single day. Anyway, I now adopted a low carb-paleo approach and my heart issues nearly disappeared (which is certainly partly due to the fact that I changed my training regimen as well). I am still training 15 hours a week, but without the really draining 5-7 hour workouts and I try to limit sleep deprivation as well. I must say that I feel much better in general since I adopted a low carb-paleo diet. I don't experience the continuous fatigue I had back when I was relying on massive amounts of sugar to pull me through the day. I am slowly turning towards ultrarunning at this stage, but without any compromises anymore with regards to health. I might compete in Ironman in the future, but only if I can dial in a near-paleo / high fat diet that is compatible with my goals (using for instance the UCAN superstarch as only artifical energy source instead of the tons of different gels/bars I used to consume, in order to rely more on fats and being less dependent on outside assistance). Right now, as I said, I train 15 hours a week with minimal carbs (around 50-80g/day), coming solely from vegetables and the residual CHO from fatty sources. Maybe twice a month, if I feel like I need to give my body a hormetic stimulation, I will drink a few glasses of milk or eat lots of fruit. Overall, I feel great, although I still tend to overeat a bit :)!