Creatine and athletes: more of the latest thinking

Q#10: Does creatine influence blood pressure?

Creatine can increase the volume of fluid within cells, which has led some to suggest that creatine may negatively impact blood pressure (ie raise it). However, in both healthy populations and those already demonstrating chronic disease, creatine supplementation was found to have zero impact on blood pressure. In fact, one study demonstrated that creatine magnified decreases in blood pressure following resistance training. At this point, there is zero evidence to suggest that creatine negatively influences blood pressure.

Q#11 Is creatine safe to consume during pregnancy?

There is emerging evidence on the role of creatine in protecting energy status in developing fetuses, as well as during complicated pregnancies. Several animal studies have been conducted investigating the effect of creatine in pregnant rodents. The findings have all suggested a neutral or slightly positive impact on fetal and maternal health. Moreover, there is no evidence that creatine has any negative health effects of women of child-bearing age. While the research is consistent that creatine is safe during pregnancy in animal populations, no human studies exist to confirm these findings at this point, with multiple studies currently underway.

Q#12: Does creatine enhance performance in adolescents?

Most of the creatine literature involves adult subjects. While studies in adolescents are lacking, those that do exist consistently support the same outcomes demonstrated in the adult literature. Improvements in both sports performance as well as the underlying physiological capacities have been shown, and adolescents can expect to receive many of the same benefits as adults. At this point, more research is needed to confirm and expand these findings because while many of the performance and physiological benefits seen in adults are experienced in adolescents, there are some key differences in developing metabolic and physiological processes.

Q#13: Does creatine adversely affect male fertility?

Creatine use has sometimes incorrectly been confused with anabolic steroid use, and as a result, many of the negative aspects of steroid use have been associated with creatine use. One of those potential negative side effects is male fertility. However, rather than detrimentally affecting fertility in males, creatine supplementation may enhance it. Creatine may facilitate sperm viability by maintaining high energy status in sperm, and low creatine levels have been associated with reduced sperm quality. Supplementation in animal models supports these theoretical considerations, with supplementation improving various aspects of sperm quality. In humans, one study demonstrated that total sperm count and semen concentration was higher in men consuming protein supplementation, with 44% of those men also consuming supplemental creatine⁽²⁾. 

Q#14: Does the brain require a higher dose of creatine than skeletal muscle?

While creatine supplementation has largely been of interest due to its effects on muscle tissue, it can also have a positive effect on brain tissue. Protocols for increasing muscle creatine stores are well documented - either using a short-term loading phase (around 20 grams/day for six days followed by 2 grams/day maintenance dosing) or a more patient approach (3 grams per days for 28 days). Unfortunately, the literature involving uptake in brain tissue is much less clear. Brain creatine metabolism is different than muscle metabolism as the brain can create its own creatine. Furthermore, creatine in the blood may have limited access to brain tissue. Across multiple studies, no dose-response relationship is apparent, although it appears that higher dosages for prolonged periods of time may be necessary to increase and optimize brain creatine levels.

Q#15: Can creatine attenuate symptoms of sleep deprivation?

It’s no secret that many humans do not get enough sleep, which can have a negative impact on multiple aspects of brain function. Interestingly, these negative effects are at least partly related to reduced creatine levels in the brain. This has prompted research into whether creatine supplementation can rescue cognitive function in conditions of sleep deprivation. Multiple studies have demonstrated this to be the case, both during normal cognitive tests as well as cognitive tests following moderate intensity exercise. Interestingly, there is evidence that both chronic creatine supplementation as well as a single large dose of creatine (0.35 grams per kilogram of bodyweight) can have a positive effect on cognitive function following sleep deprivation. However, while creatine supplementation may improve cognitive function in conditions of sleep deprivation, no evidence exists that creatine can improve cognitive function if one is well rested.

Q#16: Can creatine reduce the severity of or improve recovery from traumatic brain injury?

With greater awareness of the negative impact of repeated concussions in sport as well as military activities, there has been increased interest in the potential impact of creatine use following traumatic brain injury. There’s also interest in whether creatine supplementation can preemptively reduce the impact of head trauma. This interest stems from creatine’s role in energy homeostasis in the brain, and the cellular energy crises that arise from trauma to the brain. Rodents supplementing with creatine have been shown to experience reduced trauma following an insult to the brain. For ethical reasons, this line of research has not been pursued in humans. However, multiple studies have demonstrated that long-term creatine supplementation can improve multiple markers of brain health following brain injury. While more research is needed, the findings to date on use of creatine during traumatic brain injury are encouraging.

Act with confidence

There you have it. You should now have a much clearer understanding of the potential impacts of creatine, as well as how to use it optimally. Hopefully, you’ve learned one strategy that will change your approach to creatine, or you’ve learned something that has further solidified your approach to implementing creatine into a supplementation and performance program. It’s also possible that an answer to one of the questions has piqued your curiosity about a specific topic. Be sure to check out the relevant scientific paper for all the details. And if you haven’t already, make sure you read last month’s issue for more answers to common creatine questions!

References

1. J Int Soc Sports Nutr. 2025 Dec;22(1):2441760. doi: 10.1080/15502783.2024.2441760.  Epub 2024 Dec 25.

2. Fertil Steril [Internet]. 2020. [cited 2024 Jun 14];114(1):89–96