Cycling Creatine, against not cycling
There are two reasons for creatine cycles...
In some cases, supplementing the body with certain
substances shuts down the body's ability to produce that substance on its own. When creatine is ingested in large quantities the body shuts down production of it within the body.
The fear is that after long-term creatine usage, the body's own synthesis of creatine will not return to normal when supplementation is stopped. Studies have not shown any problems with creatine production returning to normal after short-term use. This has not been shown to occur with long-term use either but keep in mind that it is a relatively new supplement and long-term studies have not been completed.
Another reason for cycling creatine is to try and recreate the "first month" results. The best results are typically reported in the first 30 days of usage. Therefore, through creatine cycling, these "first month" results can theoretically be recreated every three or four months. Some weight trainers skip the off time and just repeat the loading phase every so often in an effort to recreate these results.
No significant creatine studies have shown dramatic performance benefits to cycling as opposed to continuous use. Personally, I cycle two months on and one month off just to be safe rather than sorry should it happen to come out twenty years from now that long-term supplementation can in fact affect the body's own production abilities. It also does seem to produce better results, or at least more dramatic results, when restarting.