Creatine is only taken up by its transporter, and changes in the activity level of this transporter are wholly causative of changes in creatine uptake. The transporter is regulated by mostly cytosolic factors as well as some external factors that affect creatine transport activity,  including extracellular creatine. Agents affecting creatine transport are further divided into positive regulators (those that increase activity of the transporter) and negative regulators (those that suppress activity).
Before getting into the nitty-gritty details about supplements, it’s important to have a good understanding of how muscle growth works. When you take a muscle growth supplement, the role it plays in helping you reach your goals should be very clear. With the supplements available on the market, you can be sure that while some serve an important purpose, others are gimmicks. It’s easier to identify the money wasters if you know how muscle building works.
Replacement therapy may produce desired results, such as greater muscle mass and a stronger sex drive. However, the treatment does carry some side effects. Oily skin and fluid retention are common. The testicles may also shrink, and sperm production could decrease significantly. Some studies have found no greater risk of prostate cancer with testosterone replacement therapy, but it continues to be a topic of ongoing research.
Parashos, S. A., Swearingen, C. J., Biglan, K. M., Bodis-Wollner, I., Liang, G. S., Ross, G. W., Tilley, B. C., and Shulman, L. M. Determinants of the timing of symptomatic treatment in early Parkinson disease: The National Institutes of Health Exploratory Trials in Parkinson Disease (NET-PD) Experience. Arch Neurol. 2009;66(9):1099-1104. View abstract.
Hacking your testosterone influences everything from body composition to energy levels to mood. It’s easy to eat more butter; it’s hard to visit a doctor and get tested, but that’s what I recommend: know your levels. If you’re 25, you’ll know what your target is when you’re 35. By the time you’ve noticed symptoms of low testosterone, it’s too late to get your “normal” measurements!
Perform the two workouts (Day 1 and 2) once each per week, resting at least a day between each. Perform the exercises marked with letters as a group. Do one set of A, rest, then one set of B, rest (note that some groups have an exercise “C”), and repeat until all sets are complete. Then go on to the next group. Perform three sets of 8–10 reps for each exercise. After a month, you’ll see how rewarding just a months in the gym can be.
Another study found that one week of creatine supplementation at 25 g/day enhanced muscular performance during repeated sets of bench press and jump squat exercise. Creatine supplementation appeared to allow the subjects to complete their workouts at a higher intensity. The researchers concluded that, over time, working at higher intensities may provide a more intense training stimulus and improved muscular adaptations .
As the name implies, the muscle power objective can be pursued if you want to achieve maximum size in your muscles or if you want them to be explosively strong (i.e. very powerful for short bursts at a time). In order to develop muscles this way you'll want to use no more than 3 sets in which no more than 8 reps are used. Muscle size and power is often used for muscles that are prominently displayed on the human figure, such as the pectorals, or the biceps and triceps.