Thanks for pointing this out. I do a form of TKD so that I don't crash and burn while playing long sessions of tennis, particularly singles. I tried playing on just my normal low carb diet and I would be ok for an hour or so of running but after than I would always hit a wall between then and two hours. The wall was not as bad as the one I've hit running marathons but was similar in affect. I like to use fast absorbing carbs like dextrose in small amounts for this purpose. Of course, as in all dietary matters, YMMV.