Here are Dr. Trager's thoughts about this. As you can see he himself talk about the importancy of carbs during long exercises. He even mention such a blasphemy as GU. (Check GU's ingredients...)
Atkins mention 80-120 carbs for people with vigorous exercise. So why it is such a big sin for a triathlete (who works much more than an average people with vigorous exercise) with 160-200 pounds weight to have 80-100 carbs after a race?

Do not get me wrong. I am fullheartedly for low carb wol, even for low carb Marathon training. I worked very hard to change my body from carb fuel mode to fat fuel mode, and had great success. (I am an amateur, but even I can now run up to 90-120 min on zero carb.) But there are limitations. I do not remember to hear from any LC endurance athlete to be totally carb free during 3+ hours training/races.

I posted this quote from Dr. Trager, because I feel, that sometimes in our respect for Atkins/LC we put unnecessary induction/OWL limits on people who need and who can have a little more carbs...

Stuart Trager, M.D.: I do personally train 15-20 hours per week and am currently preparing for the Iron Man World Championship in Hawaii this October. When exercising for more than an hour, it is important to take in carbohydrates as well as ample hydration to maximize performance. The goal while exercising is to deliver carbohydrates quickly to your muscles for energy. This is a very different condition than takes place while not exercising, and hormonally the body responds to these excess calories in a way that supports muscular efforts rather than storing extra calories as fat. Taking in carbohydrates that are rapidly absorbed is useful, and GU is one solution. I also use a complex carbohydrate product that is rapidly absorbed while exercising. It is important while doing Atkins to NOT take in carbohydrates immediately prior to exercise, as this can raise blood sugar, which stimulates insulin and can then lower blood sugar, having a very unwanted effect on performance. Carbohydrates should be consumed 2 -4 hours before exercise, and a lower glycemic snack, like an Atkins bar, would work well if food is to be eaten closer to time of exercise.

http://cgi1.usatoday.com/mchat/20030819004/tscript.htm

About CKD - see Trainersdan thread:
http://forum.lowcarber.org/showpost...266&postcount=9
Scroll down to CARB LOAD.