It really depends on how long you're carbing up for. If you've done a typical Mon - Fri no carb, then weekend carb-up, you should be pretty much carb-ed up by Sunday, assuming you ate enough carbs. The time is sufficient.
If you're carbing up more frequenly, but for shorter period of time (e.g., a carb 'spike' on Wed and Sat. - 8hr each), then the insulin might be of help.
Most frequent opinion is that after you've been low / no carbing for several days, your insulin sensitivity is so high, exogenous insulin would be overkill, i.e., not add to glycogen replenishment.
BUT, if you're doing more frequent carb spikes (I've done this training 3 x / week, carbing only for the rest of the day after workouts - no insulin, though), you might not have optimized your insulin sensitivity b/c the last carb-up was so recent, so the ins. shots might w/ glycogen replenishment.
Another thought: one benefit of the carb-up when CKD'ing is that is is anabolic and may help regain muscle lost during no-carb days. It may be that regardless if insulin does or does not help w/ glycogen replenishment, it might help stimulate greater anabolism and lesser catabolism and make the carb-up a better means of holding on to muscle when you're dieting.
Bottom line - give it a shot! Just be careful - you're not gonna need nearly as much 'slin and you'll be much more likely to go hypo after no-carbing.
Im giving that protocol a run this summer as well. Will just try to stay lean and gain a few pounds and be tight.
Actrapid 10 IU 2 times a day on mondays and thursdays. All other days will be around 100 grams of carbs, while these 2 will be in the high range.
the 4 weeks will also include 100 mg virormone EOD
On a similiar note, has anyone seen or tried Mr. X's diet where he uses 5 iu humalog with his postworkout shake. He uses no carbs, but 15g of protein per iu of slin. Supposedly this way he still gets the anabolic effects of insulin, but the fat burning of a CKD. Anyone tried it. I was considering doing 5iu Humalog post workout on MWF, then using humalog on Sat for a carb up. I don't know whether that would defeat the purpose, or if I would lose insulin sensitivity. Any input?