I can't wait to see some of the answers you get from the truly informed people around here. But until then, I'l share my personal experiences:

I'm a vegetarian low carber, and when I first went low carb, I noticed a lot of people complaining that they couldn't get into ketosis. Hmmmm. If it should be difficult for anybody, it should be difficult for a veggie, right? Anyway...

I also did a lot of exercise videos. Sometime really tough ones, too. And you know what-- [B]I NEVER[B] had any trouble getting into ketosis. (Oh happy, happy, joy, joy! Faith is dancing.) I lost 21 lbs with that combination last summer, too. In fact, I think if you exercise, you can probably eat a few more carbs than the next guy. (But YMMV.)

So, I may not have any scientific answers to your question. But I do have my own personal experience that suggest low carbing and exercise make a winning combination.

Faith