Creatine in Endurance Sports: Benefits and Limitations—Reassessing the Strength of the Scientific Evidence

Based on peer-reviewed research from international sports science journals, this article provides an in-depth analysis of the effects of “creatine” on athletic performance, combined with Taiwan-specific cycling and race scenarios, offering actionable training and nutrition recommendations.

Creatine is the most effective supplement for strength and explosive sports, but its role in pure endurance sports has long been underestimated or misunderstood. In recent years, research has reassessed its value in intermittent efforts and recovery.

In Taiwan’s endurance sports community—whether it’s the climbing enthusiasts heading west up Wuling, the long-distance riders heading east through the Huadong Rift Valley, or participants in the Sun Moon Lake loop, Taroko Marathon, or the 226 km Ironman triathlon—the topic of “creatine” matters because it directly determines whether you can maintain your pace in the latter stages of a race, avoid cramping and hitting the wall, and recover effectively between consecutive training days. Many amateur athletes pour all their energy into power training and equipment upgrades while overlooking nutrition—this “free margin for improvement.” In fact, when training volume and equipment are comparable, the quality of nutritional strategy is often the key variable separating finishers from dropouts, and personal bests from blow-ups. This article will walk you through the complete picture—from cellular molecular mechanisms, randomized controlled trial evidence, to dose-response curves and practical application—debunking long-circulated myths and putting your fueling strategy on a truly scientific foundation.

Academic Research Review

The scientific exploration of “creatine” has accumulated rich and rigorous evidence in top international journals. Below are several representative studies selected for their value in methodological design, sample populations, and strength of conclusions, which together build our current understanding of this topic:

1. Kreider RB et al. (2017, JISSN) position statement integrating hundreds of studies confirming creatine is safe and effective.

2. Tomcik KA et al. (2018, MSSE) found creatine improves cycling intermittent sprint performance.

3. Forbes SC et al. (2023, Nutrients) reviewed creatine’s secondary benefits for glycogen storage and recovery.

4. Branch JD (2003, IJSNEM) meta-analysis indicated creatine has no direct benefit for pure aerobic performance.

Taken together, these studies show that the scientific picture of “creatine” is not a single fixed conclusion, but rather one that is continually revised and deepened as research methods advance. Early studies mostly used laboratory-controlled time trials or exhaustion tests, while subsequent research gradually incorporated stable isotope tracing, muscle biopsies, functional magnetic resonance imaging (fMRI), and molecular biomarkers, allowing us to move from “observing phenomena” to “explaining mechanisms.” Notably, most high-quality studies employed randomized crossover designs, where each subject serves as both experimental and control, greatly reducing noise from individual differences. However, extrapolation of research findings still requires caution: the responses of well-trained laboratory subjects may not fully apply to general amateur athletes; and the effects of a single acute intervention may not equal long-term chronic adaptation. When reading the “effect sizes” and “statistical significance” of these studies, we must also distinguish between “statistically significant” and “practically meaningful”—a 1% improvement may decide medal placement in elite competition, but its significance is relatively limited for recreational riders.

Core Mechanisms

Creatine is stored in muscle as phosphocreatine, serving as an immediate ATP regeneration source for high-intensity, short-duration exercise. While it offers no direct energy advantage for pure endurance exercise, it enhances repeated high-intensity output during sprint and climbing segments, and indirectly supports recovery by increasing cellular hydration and glycogen storage.

To truly understand how “creatine” affects athletic performance, we must return to physiology at the cellular and systemic levels. Athletic performance is the result of multi-system coordination: the cardiovascular system handles oxygen and fuel delivery, muscle cells handle energy conversion and mechanical contraction, the central nervous system regulates motor unit recruitment and fatigue perception, while the gut and liver form the hub of nutrient absorption and metabolism. The reason the aforementioned mechanisms translate into measurable performance differences is precisely because they act on one (or more) critical links in this chain. The table below organizes the key points of action at different physiological levels for this topic, helping you build a complete mechanistic picture:

| Level of Action | Key Mechanism | Significance for Athletic Performance |

|—|—|—|

| Cellular/Molecular | Affects mitochondrial efficiency, enzyme activity, and signal transduction | Determines the efficiency of energy conversion and direction of adaptation |

| Muscle Tissue | Regulates substrate utilization, buffering capacity, and contractile function | Affects sustainable power output and fatigue onset |

| Systemic Integration | Alters blood flow distribution, thermoregulation, and hormonal environment | Determines stability and safety during prolonged exercise |

| Central Nervous System | Regulates fatigue perception, drive, and motor unit recruitment | Affects “how tired it feels” and the ability to persevere |

Two dimensions deserve special emphasis: “dose-response” and “temporal dynamics.” The same nutritional intervention, at different dosages and different timing, can produce vastly different or even opposite effects—this is precisely why many popular recommendations are one-sided. Only by understanding the mechanisms can we judge “when to use it, how much to use, and when to take it,” rather than blindly following trends.

Going further, the limiting factors of athletic performance shift dynamically with exercise intensity and duration: in short, high-intensity bursts, limitations often come from the phosphagen system and the accumulation of glycolytic byproducts; in multi-hour endurance efforts, limitations shift to the combined effects of glycogen depletion, rising core temperature, fluid and electrolyte imbalance, and central fatigue. The reason “creatine” deserves in-depth discussion is precisely because it can target certain of these limiting factors. This also reminds us that no nutritional strategy can be evaluated in isolation from the “exercise context”—a fueling rhythm suited to a 40-minute criterium may not apply to a 6-hour climbing epic, and vice versa. The more thoroughly you understand the mechanisms, the more flexibly you can adjust across different race formats, rather than clinging to a fixed formula. This ability to “adapt to context” is precisely the dividing line between amateur athletes and those who truly understand sports science.

Dose-Response Relationship

In sports nutrition, “the dose determines the toxicity, and it also determines the benefit.” Too low a dose fails to reach the physiological threshold and is futile; too high a dose may trigger side effects, gastrointestinal discomfort, or even interfere with training adaptations. The table below summarizes the dose-response correspondence for “creatine” and serves as the most important quantitative reference when developing your personal supplementation plan:

| Dose / Condition | Effect Description |

|—|—|

| Loading phase 20 g/day x 5–7 days | Rapid saturation |

| Maintenance phase 3–5 g/day | Long-term maintenance |

| Pure aerobic performance | No direct benefit |

| Intermittent/sprint segments | Clear benefit |

As the table shows, benefits often follow an “inverted U” or “threshold-plateau” curve: effects increase with dose until the effective threshold is reached, but beyond a certain plateau, not only is there no additional benefit, but marginal costs (side effects, gastrointestinal burden, financial expense) rise sharply. This means “finding your optimal dose” matters far more than “taking as much as possible.” It is recommended to progressively test different doses during training (not on race day), recording subjective feelings, gastrointestinal responses, and power data to build your own dose profile. Remember: the laboratory average is a starting point, not the endpoint; each individual’s body weight, metabolic rate, gut tolerance, and genetic background will shift the optimal dose in an individualized manner.

Differences Across Populations

The benefits of creatine are not equal for everyone. Age, sex, training status, body size, and genetic background all significantly modulate the magnitude of an individual’s response. Applying a one-size-fits-all recommendation while ignoring these differences is one of the most common mistakes in sports nutrition.

| Population Aspect | Response Characteristics | Practical Recommendations |

|—|—|—|

| Beginners vs. Advanced Athletes | Advanced athletes have more mature physiological adaptations; responses are often more consistent but with smaller marginal benefits | Beginners should start conservatively with low doses to build tolerance first |

| Men vs. Women | Differences in body weight, hormonal cycles, and sweat composition affect dosage and requirements | Women should individualize dosage by body weight and pay attention to iron status and energy availability |

| Young vs. Older | Older individuals often experience reduced absorption efficiency and anabolic resistance | Older individuals may require higher doses or better timing |

| Body Size Differences | Body weight directly affects the absolute amount calculated per mg/kg or g/kg | Always convert to a dose corresponding to individual body weight rather than copying general guidelines |

When interpreting “individual differences,” one must also be wary of a common statistical pitfall: studies mostly report “group average responses,” but beneath the average often lies enormous individual variability. Within the same intervention, some may be strong responders, some non-responders, and some even negative responders. This is why even when a study shows “average effectiveness,” you still need to confirm which category you fall into through your own experimentation. The recommended approach is to conduct personalized A/B testing: across two training sessions with conditions kept as similar as possible, apply and withhold the strategy respectively, comparing power, heart rate, and subjective feelings, then draw conclusions after repeating several times. This empirical spirit of “using yourself as the sample” is the essential path from translating group science into individual prescriptions.

Taking the common amateur endurance population in Taiwan as an example, many are middle-aged riders over 35 who train around work commitments. This group simultaneously faces declining recovery rates, insufficient sleep, and time pressure, so the “return on investment” of nutritional strategies is often higher than for younger elites—that is, correct nutritional intervention can yield relatively greater room for improvement. Female athletes, meanwhile, need to pay particular attention to the effects of the menstrual cycle on metabolism and requirements, as well as whether energy availability is sufficient, avoiding the trap of low energy availability (LEA) in the pursuit of being lighter. After understanding population differences, you will realize: truly professional nutritional advice is always an individualized prescription that “varies from person to person,” not a one-size-fits-all slogan.

Practical Training Application

Theory must ultimately be implemented in training plans and on race day. Below is a practical framework for translating creatine into concrete training and competition operations:

• Pre-race testing principle: All nutritional strategies must first be rehearsed in training; “never try anything new on race day” is an iron rule. Gastrointestinal tolerance to new products takes time to build.

• Periodization mindset: Align nutritional strategies with training phases—the base phase can focus on adaptation-oriented strategies, while the pre-season shifts to performance-oriented fueling optimization.

• Progressive introduction: Start with low doses and low frequency, adjust gradually based on bodily responses, and build a personalized dosage and timing profile.

• Data tracking: Combine power meter data, heart rate, rating of perceived exertion (RPE), and gastrointestinal comfort records to objectively evaluate whether an intervention is truly effective.

• Holistic context: Nutrition is one component of training, sleep, recovery, and psychology; no single supplement can compensate for sleep deprivation or flawed training design.

Using a one-week training schedule as an example, it is recommended to rehearse different fueling scenarios during key high-intensity sessions in the week (such as threshold intervals and repeated climbs) and the weekend long ride: high-intensity days emphasize rapid energy supply and central activation, while long-distance days emphasize sustained energy delivery, gastrointestinal tolerance, and recovery. Through repeated rehearsal, your body can execute the optimal fueling rhythm “automatically” on race day, leaving mental resources for pacing and tactical decisions. Remember, the goal of a nutritional strategy is not to pursue theoretical perfection, but to remain stable and reliable under the fatigue, heat, and pressure of a real race course.

When executing a nutrition plan, the most common mistake many people make is “being serious only on race day while eating carelessly during regular training.” This is precisely putting the cart before the horse: regular training is the ideal laboratory for building gut tolerance, testing dosages, and cultivating fueling rhythm. If you hope to execute a fueling plan of 80 grams of carbohydrates per hour on race day, you must rehearse it repeatedly in training until your body becomes accustomed to it; if you intend to rely on a certain supplement, you must confirm in training that it is genuinely effective for you and free of side effects. It is recommended to integrate a nutrition log with your training log, recording the fueling content, intake timing, gastrointestinal responses, and performance data for each key session. After weeks to months of accumulation, the value of this personalized database will far exceed any generic nutrition guide. Additionally, do not overlook the often-underestimated “post-training recovery fueling” component—the quality of recovery between consecutive training days often determines whether you can steadily accumulate training volume without injury, and training volume is the most fundamental engine of long-term progress. Treat nutrition seriously as part of training, rather than a last-minute accessory before races, and your improvement curve will be noticeably different.

Local Application in Taiwan

Taiwan’s unique climate, terrain, and race culture add localized considerations to the application of creatine. Taiwan’s summer is hot and humid, with apparent temperatures often exceeding 35°C, and sweat rates and fluid/electrolyte losses far exceed those in the research contexts of temperate countries. This means that hydration and fueling recommendations from foreign literature often need to be “adjusted upward.” In events like the Westbound Wuling climb, which ascends from sea level to 3,275 meters, the appetite suppression at altitude, low temperatures, and prolonged exercise pose a severe test for energy planning.

Regarding local fueling options, Taiwan’s abundant bananas, sweet potatoes, pineapples, sports drinks, and convenience store ready-to-eat foods can all be incorporated into fueling strategies; the extremely high density of convenience stores also makes mid-ride refueling on long rides relatively easy. It is recommended that Taiwanese riders planning classic routes such as Sun Moon Lake, Wuling, Beiyi, Buyanting, and the East Coast Crossing inventory the fueling points along the way in advance, and strengthen sodium and fluid intake in response to Taiwan’s hot and humid environment. Athletes in the Taroko Marathon, Taipei Marathon, and various local triathlon events should likewise incorporate the above local climatic factors into their individualized nutrition plans to perform at their best under subtropical conditions.

Debunking Common Myths

Myth: The myth is that “creatine only makes you heavier and slower, and is unsuitable for cycling.” In fact, the added weight is mainly intramuscular water, which has minimal impact on climbers, while the benefits for sprinting and recovery are often overlooked.

Such myths spread widely because they “sound reasonable,” are easily passed by word of mouth, or are amplified by marketing rhetoric. Yet the value of science lies precisely in testing intuition with rigorous evidence: many seemingly obvious notions fail to hold up under scrutiny in randomized controlled trials. Sports nutrition is especially rife with oversimplified “panacea” style promotion, compressing complex dosages, timing, and individual differences into a single slogan. The next time you hear a dogmatic nutritional claim, it is worth asking: “What is the level of evidence for this claim? Who is the target population? Are the dosage and timing clearly specified?” Cultivating this evidence-based critical thinking is more valuable than memorizing any single conclusion, and it is a key step for amateur athletes moving toward scientific training.

Conclusion

Creatine is a topic in sports nutrition that combines both theoretical depth and practical value. From the academic evidence reviewed in this article, its benefits are real, but it is by no means an unconditional panacea—the key lies in correct dosage, appropriate timing, individualized adjustment, and synergy with overall training, recovery, and sleep. For endurance sports enthusiasts in Taiwan, while grasping the scientific principles, it is equally important to integrate local climate, terrain, and race characteristics to transform general guidelines into a personalized prescription that suits oneself. May every rider sweating on Wuling, in the rift valleys, and on round-island routes break through their limits through science-based nutritional strategies and enjoy the pure joy that sport brings. Before you next step onto the race course, remember—your fuel bottle contains not just water and sugar, but an entire validated system of sports science.

Related Reading

• Creatine Is Not Just for Strength Training: Hidden Uses and Evidence for Endurance Athletes
• Is Creatine Supplementation Useful for Endurance Performance? Scientific Analysis and Recommendations
• The Benefits of Caffeine for Endurance Performance: Latest Meta-Analysis of 3-6 mg/kg Dosing and Individual Differences
• Research on Phosphocreatine Resynthesis Rate and Energy Systems in Repeated Sprint Interval Training