Generally, there are three optimal times to take creatine: 1) First thing in the morning in a fasted state when the muscle cells are like sponge, dense with enzymes favourable to nutrient absorption; 2) Pre-workout, so that the workout itself provokes the uptake of nutrients. Put differently, the idea of taking creatine supplements pre-workout is that training provokes better vasodilation, flooding muscle cells with nutrient-rich blood, leading to superior post-training repair and growth processes. Furthermore, muscle contraction (during exercise) requires adenosine triphosphate (ATP), the body’s energy currency. Unfortunately, as is well-known, ATP is highly unstable, delivering energy for about 10 seconds. Fortunately, the consumption of creatine helps address this problem. In skeletal muscle cells, creatine is converted to phosphocreatine or creatine phosphate by the enzyme creatine kinase (CK) and stored there. When required, the phosphate molecule is then donated to adenosine triphosphate (ADP) to form ATP. The metabolization of ATP creates energy, making muscle contraction possible. So, creatine can act as an ATP generator during exercise. By providing the body with more ATP, creatine helps enhance energy and strength, leading to an increase in (type 2) muscle fibers recruited and stimulated. And by recruiting ATP, creatine ensures the body by-passes glycolysis, down-regulating the release of lactic acid, leading to stronger and longer muscular exertion. These are all favourable conditions for intense exercise; 3) Within 90 minutes post-workout, to take advantage of the so-called Anabolic Window of Opportunity when glycogen stores are depleted and the body is in an optimal state for anabolism. As is well-known, intense exercise triggers insulin release, up-regulates androgen-receptor sites, and depletes ATP and glycogen stores. Put differently, the body enters a catabolic state and the receptor sites become supersensitive to nutrient uptake to induce anabolism. However, this anabolic activity has to be fuelled by ATP, and since creatine is a substrate for ATP production via phosphocreatine synthesis, ATP upregulation via creatine supplementation, in the presence of macronutrients such as proteins and carbohydrates, becomes very attractive.
As for creatine loading, this is purely a matter of individual preference. Recall our bodies synthesize creatine daily from the amino acids glycine, arginine, and methionine. Besides, we also obtain creatine from diet (meat/animal sources). An average, healthy, 70kg athlete has creatine reserves of about 120gr. He uses up about 2.5gr - 3gr or so daily in metabolic processes, depending on his level of activity. Some of this creatine need is replenished via endogenous creatine synthesis and the rest directly from diet. Personally, therefore, I neither see the need to load nor do I take mega-doses (>5gr daily) of creatine.
