In regard to carbohydrate oxidation during exercise, it appears that rats subject to intermittent physical exercise (which utilizes glycogen) have decreased lactate production during said exercise, suggesting a preservation of glycogen usage. This occurred alongside an increase in glycogen stores. This is thought to be due to phosphocreatine donating phosphate to replenish ATP. Without any changes in whole body metabolic rate, it indirectly causes less glucose to be required to replenish ATP, due to a quota needing to be met during exercise and creatine phosphate taking up a relatively larger percentage of said quota.
The creatine kinase (CK) enzyme in rat heart tissue appears to have a KM around 6mM of creatine as substrate. and is known to positively influence mitochondrial function as higher cytoplasmic phosphocreatine concentrations (not so much creatine per se) increase the oxidative efficiency of mitochondria This is thought to be due to the transfer of high energy phosphate groups.
While the aforementioned study insinuated that after was better, at this time the “just take it at any time” or maybe more appropriately, “take it when it works for you” is the best way to go. Many people take supplements that include creatine, so if that’s in your pre- or post- workout drink, you should receive all the benefits. Optimal dosing still appears to be between 2 to 5 grams per day. You can “load” for the first 5 to 7 days to help saturate your cells, but beyond that there’s no benefit to taking large amounts. So save your money and take the smaller dose; it’ll still offer maximum results.
I always recommend starting on the low end of the scale. Only increase volume when you absolutely need to. So, if you’re training chest, you could do 6 work sets of dumbbell bench presses to start out, breaking down to two sets per workout for three sessions per week. You can gradually add sets from there, experimenting with different training splits that will allow you to get in more volume without overtraining (we’ll discuss training splits next).
The first thing you need is a weight training program that signals the muscle building process to begin. Research has shown that a well designed program will generate this “signal” via a combination of progressive tension overload (as in, getting stronger over time), metabolic stress (as in, fatiguing the muscle and getting “the pump”), and muscular damage (as in, actual damage to the muscle tissue itself).
It is suggested [16,37] that another mechanism for the effect of creatine could be enhanced muscle glycogen accumulation and GLUT4 expression, when creatine supplementation is combined with a glycogen depleting exercise. Whereas it has been observed  that creatine supplementation alone does not enhance muscle glycogen storage. Hickner et al  observed positive effects of creatine supplementation for enhancing initial and maintaining a higher level of muscle glycogen during 2 hours of cycling. In general, it is accepted that glycogen depleting exercises, such as high intensity or long duration exercise should combine high carbohydrate diets with creatine supplementation to achieve heightened muscle glycogen stores .
Few supplements have the solid scientific foundation that creatine has. Studies show that it's effective for 80 percent of those who use it. Since creatine is found naturally in meat, the more meat you eat, the less likely you'll need creatine supplementation. Vegetarians or those who rarely eat meat, however, can get huge boosts from most creatine supplements.
One pilot study using 150mg/kg creatine monohydrate for a five day loading phase followed by maintenance (60mg/kg) for the remainder of the five weeks noted that supplementation was associated with fewer muscle symptoms and complaints alongside improved muscular function, yet a later trial trying to replicate the obsevations using 150mg/kg daily for five weeks noted the opposite, that creatine supplementation exacerbated symptoms.