A study by Australian researcher Paul Cribb, Ph.D., examined how the intake of protein and carbs is affected by a high-protein diet and whether such an eating plan diminishes the requirement for supplemental protein and carbs. What happens when you add creatine to the mix—does it increase muscle gains more than just protein and carbs alone?
The primary purpose of the study was to compare the effects of supplement timing. The subjects, who were all bodybuilders, followed their usual diets in addition to taking the supplements. The subjects, divided into two groups, were all monitored during the course of a 10-week weight-training program.
One group took in one gram per kilogram of bodyweight of a combination of whey protein, carbohydrate and creatine before and after a workout. The other group had the same combination in the morning and evening, away from the workout.
Having the supplement before and after training resulted in greater improvements in strength and body composition. Specifically, the men in that group gained more muscle and lost more bodyfat. Cribb noted that essential amino acids taken before and after training promote a higher level of muscle protein synthesis. The simple carb used in the study, glucose, enhanced the anabolic effect by promoting an insulin release that led to greater amino acid uptake into muscle. The carbs also reduced muscle protein breakdown during the workout, which further enhanced the anabolic effect. The fast-acting whey was particularly effective, since the rapid protein release sets into motion molecular processes that result in muscle protein synthesis.
Those in the pre- and postworkout group also showed higher muscle creatine levels than the other group.
Cribb suggested that the creatine intake enhanced cellular energy reactions and may have upgraded muscle hypertrophy–related gene activity.The pre- and postworkout group also had higher muscle glycogen levels, thought to be related to the intake of simple carbs. Increased muscle glycogen aids muscle repair processes after intense exercise, as well as replenishing the primary fuel for bodybuilding, glycogen. Sufficient glycogen replenishment ensures more intense workouts and, subsequently, greater gains in muscular size and strength.
The study underscores the importance of nutrient timing; that is, taking in nutrients when the need for them is most critical. In practical terms, that means taking in a combination of protein, carbs and creatine before and after training. Taking the same nutrients at other times won’t produce comparable results.
Cribb, P.J., and Hayes, A. (2006). Effects of supplement timing and resistance exercise on skeletal muscle hypertrophy. Med Sci Exer Sports. 38(11):1918-25.
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