Does Creatine Actually Help Cyclists? What the Evidence Says

Why Cyclists Ask About Creatine

Creatine has a reputation as a strength and power supplement, the thing lifters and sprinters take, not something an endurance cyclist needs. A lot of riders I coach ask about it and assume the answer is no, it's not for them. The real answer is more specific than that: creatine does very little for steady-state aerobic riding, but it has a real, evidence-backed role for the kind of repeated hard efforts that actually decide races, and for how your brain holds up when you're running on too little sleep. Here's what the research supports.

What Creatine Actually Does

Creatine supplementation raises the phosphocreatine content of your muscles, which expands your capacity to rapidly resynthesize ATP during hard efforts and helps buffer the hydrogen ion accumulation that contributes to fatigue during high-intensity work [1]. That's a mechanism tied to short, intense, repeatable efforts, not to the aerobic system that dominates a five-hour endurance ride.

What It Doesn’t Do for Steady-State Riding

If you're hoping creatine improves your FTP or your ability to hold steady power for hours, the evidence doesn't support that. A controlled study using a cycle ergometer had subjects load creatine for 5 days at 20 g/day, then continue at 2 g/day for 6 weeks, and measured whole-body and muscle oxidative capacity, substrate utilization during submaximal exercise, and time-trial performance. Repeated sprint performance improved. Time-trial performance and oxidative capacity did not [2]. Creatine is not an aerobic engine booster.

Where It Actually Helps On the Bike

The more useful question for a road or crit racer isn't whether creatine improves your engine, it's whether it improves your ability to repeat hard efforts within a race. A 2023 review focused specifically on endurance sport concluded that creatine increases time to exhaustion during high-intensity endurance activity, largely through increased anaerobic work capacity, and is more likely to help in events that involve multiple surges in intensity or a hard finishing effort, exactly the demands of criteriums, hilly road races, and attacking racing, than in a flat, steady time trial [1]. If your race gets decided by who can respond to the third attack on the climb, or who has something left for the sprint after four hours, that's the physiology creatine is actually supporting.

The Mental Fatigue Angle

Late in a long ride or a multi-day stage race, decision-making tends to fall apart before your legs do, and this is where creatine's other role gets relevant. Creatine is a key part of brain energy metabolism, and supplementation raises brain creatine content, with effects that show up specifically during periods of acute metabolic stress like sleep deprivation, mental fatigue, and hypoxia [3].

Two controlled studies combining sleep deprivation with intermittent exercise found that a creatine-loading protocol (5 g, four times a day, for 7 days) produced measurably better performance on complex decision-making and reaction-time tasks after 24 to 36 hours of sleep loss, along with better mood state, compared to placebo [4][5]. That maps directly onto stage racing, early race-day travel across time zones, or any training block where you're stacking hard sessions on too little sleep and still need to make good tactical decisions.

There's a broader signal on memory as well: a systematic review and meta-analysis of ten randomized controlled trials found creatine supplementation improved memory performance compared to placebo, with a stronger effect in older adults than in younger ones [6]. None of this is a substitute for actual sleep, but if a training block or a race has you running a deficit, it's a real reason creatine earns its place beyond the anaerobic work capacity it provides on the bike.

The Glycogen Loading Connection

There's a practical angle here that's specific to endurance athletes and often gets missed: creatine loading appears to enhance glycogen storage. One study found that a standard creatine loading protocol increased muscle glycogen content by about 18%, independent of any change in glucose transporter expression [7]. A separate study went further, showing that a 5-day creatine load performed before a standard glycogen loading protocol produced a significantly larger glycogen supercompensation than glycogen loading alone, with muscle glycogen content increasing by roughly 53% after the creatine-primed protocol compared to about 4% without it [8]. If you're carb-loading for a big event, creatine loading beforehand may make that carb-load more effective, not just your intervals.

Dosing

The standard protocol, and the one with the most research behind it, is creatine monohydrate specifically, not the various other forms marketed as superior. You can either load at 20 g/day, split into four 5 g doses, for 5 to 7 days and then drop to a 3 to 5 g/day maintenance dose, or skip the loading phase and go straight to 3 to 5 g/day, which saturates muscle creatine stores over roughly 3 to 4 weeks instead of a week [9]. Loading gets you there faster if you have a specific event coming up. Otherwise, the slower route works just as well and is easier to stay consistent with.

The Water Weight and Kidney Questions

Creatine does increase body mass, mostly through an increase in fat-free mass and intracellular water, which showed up clearly in the cycling study cited above and is a real tradeoff for anyone racing uphill where weight matters [2]. On kidney safety, in people without pre-existing kidney disease, the research consistently shows no meaningful effect on kidney function, even at high doses over long periods. The ISSN's position stand states that short- and long-term supplementation, up to 30 g/day for 5 years, is safe and well tolerated in healthy individuals [9], and a dedicated review of creatine and kidney function in athletes reached the same conclusion, while still recommending caution for anyone with existing kidney disease or risk factors for it [10].

What I Actually Recommend

If you race crits, hilly road races, or anything decided by repeated hard efforts and a finishing kick, creatine is a reasonable, well-supported addition, and the added body mass is a small price for the anaerobic work capacity you get in return. If you're purely doing long steady-state efforts where weight matters more than repeatability, like a hilly gran fondo or an FTP-limited time trial, the case is weaker, and you should weigh the extra kilogram or two against the actual benefit you'd get. The sleep-deprivation and glycogen-loading effects are relevant to almost everyone heading into a demanding stage race or a big event, regardless of what kind of racing you do.

References

[1] Forbes, S. C., Candow, D. G., Neto, J. H. F., Kennedy, M. D., Forbes, J. L., Machado, M., Bustillo, E., Gomez-Lopez, J., Zapata, A., & Antonio, J. (2023). Creatine supplementation and endurance performance: surges and sprints to win the race. Journal of the International Society of Sports Nutrition, 20(1), 2204071.

[2] van Loon, L. J. C., Oosterlaar, A. M., Hartgens, F., Hesselink, M. K. C., Snow, R. J., & Wagenmakers, A. J. M. (2003). Effects of creatine loading and prolonged creatine supplementation on body composition, fuel selection, sprint and endurance performance in humans. Clinical Science, 104(2), 153-162.

[3] Candow, D. G., Pratt, J., Fabiano, N., Gordji-Nejad, A., Smith, A., Rawson, E. S., Moriarty, T., Forbes, S. C., & Kerksick, C. M. (2026). Creatine supplementation and the brain: have we put the cart before the horse? Journal of Dietary Supplements, 23(2), 175-204.

[4] McMorris, T., Harris, R. C., Howard, A. N., Langridge, G., Hall, B., Corbett, J., Dicks, M., & Hodgson, C. (2007). Creatine supplementation, sleep deprivation, cortisol, melatonin and behavior. Physiology & Behavior, 90(1), 21-28.

[5] McMorris, T., Harris, R. C., Swain, J., Corbett, J., Collard, K., Dyson, R. J., Dye, L., Hodgson, C., & Draper, N. (2006). Effect of creatine supplementation and sleep deprivation, with mild exercise, on cognitive and psychomotor performance, mood state, and plasma concentrations of catecholamines and cortisol. Psychopharmacology, 185(1), 93-103.

[6] Prokopidis, K., Giannos, P., Triantafyllidis, K. K., Kechagias, K. S., Forbes, S. C., & Candow, D. G. (2023). Effects of creatine supplementation on memory in healthy individuals: a systematic review and meta-analysis of randomized controlled trials. Nutrition Reviews, 81(4), 416-427.

[7] van Loon, L. J. C., Murphy, R., Oosterlaar, A. M., Cameron-Smith, D., Hargreaves, M., Wagenmakers, A. J. M., & Snow, R. (2004). Creatine supplementation increases glycogen storage but not GLUT-4 expression in human skeletal muscle. Clinical Science, 106(1), 99-106.

[8] Nelson, A. G., Arnall, D. A., Kokkonen, J., Day, R., & Evans, J. (2001). Muscle glycogen supercompensation is enhanced by prior creatine supplementation. Medicine & Science in Sports & Exercise, 33(7), 1096-1100.

[9] Kreider, R. B., Kalman, D. S., Antonio, J., Ziegenfuss, T. N., Wildman, R., Collins, R., Candow, D. G., Kleiner, S. M., Almada, A. L., & Lopez, H. L. (2017). International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. Journal of the International Society of Sports Nutrition, 14, 18.

[10] Davani-Davari, D., Karimzadeh, I., Ezzatzadegan-Jahromi, S., & Sagheb, M. M. (2018). Potential adverse effects of creatine supplement on the kidney in athletes and bodybuilders. Iranian Journal of Kidney Diseases, 12(5), 253-260.