Written by: Diego Campos, NSCA-CPT, Jorge L. Petro, PhD, CSCS & Scott Forbes, PhD, FISSN
Creatine (Cr) is a non-protein amino acid synthesized primarily in the liver, kidneys, and pancreas (1–3). Approximately 95% of the body’s creatine pool is stored in skeletal muscle, but high concentrations have also been found in the brain and other energy-demanding cells—such as cardiomyocytes, hepatocytes, kidney cells, inner ear cells, enterocytes, spermatozoa, and photoreceptor cells (1). Due to its crucial role in cellular energy homeostasis, Creatine monohydrate is one of the most extensively studied nutritional and ergogenic supplements, with strong evidence supporting its safety and efficacy (1,2). Its applications range from sports nutrition, where athletes across various disciplines use it to enhance performance (2–4), to health and disease management (e.g., Duchenne muscular dystrophy, sarcopenia, and creatine deficiency syndromes) (1,2).
About two-thirds of intramuscular creatine exists as phosphocreatine (PCr), while the rest is free creatine (2). On a regular diet providing 1-2g of creatine per day, muscle Cr and PCr stores reach only 60-80% saturation (2,3). Supplementing with creatine monohydrate can help increase these levels by 20-40% (2,3).
Creatine monohydrate supplementation has been proven effective in enhancing strength performance (3). Additionally, multiple studies suggest it can increase body mass and fat-free mass (FFM), supporting training adaptations in athletes (2,5,6). With this in mind, this blog explores alternative perspectives on CrM’s impact on endurance performance, based on available evidence. Although CrM hasn’t been shown to directly improve endurance performance in endurance athletes, its benefits in other areas (such as training capacity, fatigue reduction, and recovery) could still be valuable for endurance athletes.
While creatine monohydrate supplementation improves strength, its effect on endurance performance remains debated. After the analysis of several endurance test outcomes (6-km terrain run, continuous treadmill, shuttle run, incremental test in rowing and cycle ergometer, among others), Fernández-Landa et al. (3) concluded in a systematic review with meta-analysis that CrM does not enhance endurance performance in trained individuals. Similarly, in another meta-analysis, Gras et al. (4) reported that creatine supplementation has a negative effect on VO2max, regardless of the characteristics of training, supplementation, or population characteristics.
However, these findings should be interpreted cautiously, as the studies included in the analysis (3) did not account for key factors like strength training (ST) programming and nutritional strategy—both of which influence FFM gains and exercise adaptation (2). Importantly, it’s unclear whether the ST protocols (critical for athlete preparation) were designed to optimize both strength and muscular endurance (7). Thus, increases in body mass may not have directly impacted performance. In addition, previous studies have shown that creatine monohydrate supplementation improves critical power (8) and intense interval endurance training (9). In addition, a nutrition plan tailored to total energy expenditure could have minimized unwanted body mass gains (2). Finally, combining creatine and glycerol seems effective in reducing thermal and cardiovascular strain during exercise in the heat without negatively impacting on running economy (10).
While CrM hasn’t demonstrated a direct ergogenic effect in various endurance protocols (2,3,6), some studies suggest it may reduce exercise-induced inflammation and muscle damage, aiding recovery and alleviating post-exercise soreness (6). It may also help maintain (or even increase) MM during training (2). Thus, beyond its potential endurance-specific effects, shouldn’t we also consider creatine’s benefits for recovery, health, and overall athlete well-being when evaluating its use in endurance sports?
One notable study by Santos et al. (6) used a double-blind trial to assess the effects of creatine monohydrate on cellular damage and inflammation markers after a 30 km race. Thirty-four male athletes were divided into two groups: one receiving 20 g/day of CrM (split into 4 doses of 5 g) with 60 g of carbohydrates (maltodextrin, n=18), and a placebo group receiving only carbohydrates (n=16). The intervention lasted five days before the race. Both groups completed the 30 km race with times similar to their personal best, confirming creatine monohydrate didn’t affect performance. However, pre-race creatine supplementation reduced post-exercise markers of cell death, muscle soreness, and protein breakdown.
To maximize muscle creatine reserves, science-backed strategies for creatine monohydrate supplementation include (Figure 1):
Figure 1. Features of creatine monohydrate supplementation for endurance (2,3).
Beyond inflammation and muscle damage, CrM has consistently shown other potential benefits for EAs, including:
- Lower risk of sports injuries
- Faster recovery from musculoskeletal and post-surgical injuries
- Improved exercise tolerance in hot conditions
- Higher glycogen loading, enhancing interval training performance, and increasing lactate threshold
- It might improve critical power
- It also supports exercise adaptation by speeding up recovery and preserving FFM during training cycles
Creatine monohydrate benefits extend beyond sports performance to general health (1,2). Its effects go far beyond energy metabolism and muscle recovery, covering areas like neuroprotection (e.g., brain and spinal cord health), creatine synthesis deficiencies, neurodegenerative diseases, ischemic heart disease, and aging (2). This positions creatine monohydrate not just as a recovery aid but as a strategy to preserve muscle integrity, optimize physiological adaptation, and support long-term health—even in endurance disciplines like running.
Ultimately, creatine’s impact on endurance athletes depends on multiple factors, including nutrition and ST programming, both crucial for energy metabolism optimization. Beyond performance, creatine monohydrate offers benefits for muscle recovery, FFM preservation, and neuroprotection, making it a valuable nutritional tool for health and physical performance. Its use in endurance athletes should be evaluated holistically—not just for immediate performance gains but also for its role in long-term physiological optimization and muscle health.
References
1. Bonilla DA, Kreider RB, Stout JR, et al. Metabolic Basis of Creatine in Health and Disease: A Bioinformatics-Assisted Review. Nutrients. 2021;13(4):1238.
2. Richard B. Kreider PhD, FISSN, FACSM. Essentials of Exercise & Sport Nutrition: Science to Practice. Lulu Press, 2019.
3. Fernández-Landa J, Santibañez-Gutierrez A, Todorovic N, Stajer V, Ostojic SM. Effects of Creatine Monohydrate on Endurance Performance in a Trained Population: A Systematic Review and Meta-analysis. Vol. 53, Sports Medicine. Springer Science and Business Media Deutschland GmbH; 2023. p. 1017–27.
4. Gras D, Lanhers C, Bagheri R, Ugbolue UC, Coudeyre E, Pereira B, Zak M, Bouillon-Minois JB, Dutheil F. Creatine supplementation and VO2max: a systematic review and meta-analysis. Critical reviews in food science and nutrition. 2023; 63(21): 4855-4866.
5. Benardot D. Manual ACSM de Nutrición para Ciencias del Ejercicio. 2019.
6. Santos RVT, Bassit RA, Caperuto EC, Costa Rosa LFBP. The effect of creatine supplementation upon inflammatory and muscle soreness markers after a 30km race. Life Sci. 2004; 75(16): 1917–1924.
7. NSCA-National Strength & Conditioning Association, ed. Essentials of strength training and conditioning. Human kinetics, 2021.
8. Schäfer LU, Hayes M, Dekerle J. Creatine supplementation improves performance above critical power but does not influence the magnitude of neuromuscular fatigue at task failure. Exp Physiol. 2019;104(12):1881-1891.
9. Kendall KL, Smith AE, Graef JL, et al. Effects of four weeks of high-intensity interval training and creatine supplementation on critical power and anaerobic working capacity in college-aged men. J Strength Cond Res. 2009;23(6):1663-1669.
10. Beis LY, Polyviou T, Malkova D, Pitsiladis YP. The effects of creatine and glycerol hyperhydration on running economy in well trained endurance runners. J Int Soc Sports Nutr. 2011;8(1):24.
About the authors
Prof. Scott Forbes, PhD
Associate professor in the department of Physical Education Studies at Brandon University and an adjunct professor in the faculty of Kinesiology and Health Studies at the University of Regina. View the full author profile →