In a review of creatine supplementation studies, Persky and Rawson found no increase in serum creatinine in 12 studies, 8 studies showed an increase that remained within the normal range, and only 2 studies showed an increase above normal limits (although not different from the control group in one study). Both blood and urinary creatinine may be increased by ingestion of creatine supplementation and creatine containing foods, such as meat. However, the amount of creatinine in the blood is related to muscle mass (i.e. males have higher blood creatinine than females) and both dietary creatine and creatinine intake . As a result, creatine supplementation may not lead to water retention. Some anecdotal evidence indicates that creatine users perceive supplementation to result in some adverse effects . In the early 2000’s, with limited data and based primarily on speculation, the American College of Sports Medicine (ACSM) recommended that individuals controlling their weight and exercising intensely or in hot environments should avoid the use of creatine supplementation . However, in the van der Merwe et al. study, no increase in total testosterone was found in the 16 males who completed the study. It is important to note that the results of van der Merwe et al. have not been replicated, and that intense resistance exercise itself can cause increases in these androgenic hormones. However, the literature indicates that creatine alone (that is, without a concomitant resistance training program) is unlikely to result in substantial gains in muscle strength and functional performance 95, 111–113, although it does improve some parameters of muscle fatigue 114–116. While resistance training is considered cornerstone in the treatment of sarcopenia , accumulating evidence indicates that creatine supplementation may enhance the anabolic environment produced by resistance training, subsequently mitigating indices of sarcopenia 9, 10, 19, 27. Perhaps one of the most promising conditions that could benefit from creatine supplementation is age-related sarcopenia. The amount of "free" testosterone — the portion that is active in tissues — depends on several factors, including fluid balance. Once in circulation, testosterone binds to proteins such as albumin and sex hormone-binding globulin (SHBG). When we talk about testosterone and hydration, the relationship goes both ways. If any of these happen, the doctor may recommend adjusting fluid intake, changing the TRT dose, or checking kidney and heart function. There is no single rule for how much water everyone needs, but TRT can increase water demand in several ways. TRT can indirectly influence hydration through its effects on red blood cells, muscle mass, and metabolism. Fluid retention may seem opposite to dehydration, but both relate to how the body manages fluids. While TRT can increase red-cell mass, it can also cause water retention in some people Testosterone can influence how the kidneys handle sodium. These hormone swings might influence how the body regulates fluids, but no studies have compared hydration outcomes between different TRT delivery methods. For example, one study looked at how dehydration affects testosterone levels in athletes. As the therapy changes how the body builds tissue, produces red blood cells, and manages fluids, it may alter hydration needs in subtle ways. Each method has pros and cons, and doctors usually monitor patients closely to ensure that testosterone levels stay within a healthy range and that side effects remain minimal.
