Creatine for Endurance Athletes: What You Need to Know

Creatine for endurance athletes can be confusing. You probably associate it with bodybuilders and sprinters, not marathoners, cyclists, or triathletes. Yet more endurance athletes are experimenting with creatine to see if it can boost power, recovery, or finishing speed.

Below, you will learn how creatine works, what the research actually says for endurance performance, and how to decide if it makes sense for your training.

What creatine is and how it works

Creatine is a compound that your body makes naturally from amino acids. You also get some from foods like red meat and fish. Most of your creatine is stored in muscle as phosphocreatine, which helps quickly regenerate ATP, the main energy currency in your cells.

During short, intense efforts, such as a sprint or a hard surge on the bike, ATP gets used up quickly. Extra phosphocreatine lets you resynthesize ATP faster, so you can produce more power for a little longer. This is the main reason creatine is known for improving high‑intensity, short‑duration efforts.

Supplementing with creatine monohydrate typically raises your muscle creatine stores by about 20 percent. That increase improves your ability to sustain repeated bursts of intense work, and it can also enhance your training quality over time (PMC).

Why creatine matters for endurance sports

You might wonder how a supplement that supports 5 to 30 second efforts can help you in events that last hours. The key is that endurance sports often include critical high‑intensity moments.

If you are a cyclist, triathlete, rower, or runner, your race probably includes surges, hills, accelerations out of corners, and a final sprint. Research shows that creatine supplementation improves high‑intensity, short‑duration exercise capacity by increasing ATP availability. This lets you hold higher intensities during repeated efforts in training, which may carry over to better performance in those decisive race moments (TrainingPeaks).

Creatine also appears to support:

Better anaerobic work capacity and longer time to exhaustion during intermittent high‑intensity efforts, with studies reporting interval power output increases up to 18 percent without impairing oxygen uptake (PMC)
Improved phosphocreatine stores and hydrogen ion buffering, which can delay fatigue in efforts longer than about 3 minutes, such as sustained climbs or hard pulls in a paceline (PMC)

In other words, creatine for endurance athletes is less about making you faster at your easy pace and more about giving you a bigger gear when it counts.

What the research says for endurance athletes

The science is mixed, which is why opinions on creatine for endurance athletes vary. A few key findings can help you set realistic expectations.

High‑intensity power and sprint finishes

Several studies have looked at cycling performance in trained endurance athletes. A 2019 study found that creatine monohydrate significantly increased cycling power output in well‑trained triathletes, particularly during the cycling segments of triathlons, allowing for more efficient riding at higher power (TrainingPeaks).

A 2023 review reported that creatine supplementation improved anaerobic work capacity and time to exhaustion during intermittent high‑intensity endurance efforts, such as repeated sprints or surges. In some cases, interval power output increased by up to 18 percent while oxygen uptake remained unchanged (PMC).

If your sport involves repeated surges, fast finishes, or tactical accelerations, these effects are directly relevant to you.

Overall endurance performance

When it comes to steady‑state endurance, the picture is more modest. A systematic review published in May 2023 found that creatine monohydrate was generally ineffective at improving endurance performance in trained athletes under 35 years old in short‑duration studies. However, longer supplementation periods, such as 70 days in rowers, showed significant benefits, which suggests that both duration of use and the specific sport matter (TrainingPeaks).

Creatine also enhances muscle glycogen storage, likely through improved insulin sensitivity, glucose transporter upregulation, and related mechanisms. This can support high‑intensity aerobic work, although performance improvements on pure endurance metrics are typically modest (PMC).

In one review, elite cyclists who combined creatine with carbohydrates had higher muscle glycogen and showed better power output in closing sprints of a 120‑kilometer time trial (PMC).

Recovery and training quality

For endurance athletes, recovery between sessions can be just as important as performance within a single workout.

Research indicates that creatine can accelerate recovery from intense exercise by reducing muscle damage. That can help you tolerate heavier training loads and reduce injury risk over time (TrainingPeaks).

By improving recovery and allowing more high‑quality intervals in your plan, creatine may indirectly support endurance gains, even if it does not drastically change your VO2 max or threshold pace by itself.

Benefits you might notice

If you decide to use creatine, here are the main benefits you are most likely to feel in your training and racing.

More power during surges and sprints

You may find it easier to:

Close gaps in a bike race
Accelerate up short hills
Respond to attacks in a group
Finish with a stronger sprint

These advantages are especially valuable in sports where race‑defining moments come down to short, intense efforts, such as cycling, triathlon, swimming, rowing, mountain biking, and cross‑country skiing (PMC).

Better training quality

Because creatine supports repeated high‑intensity efforts, you might be able to hold your target power or pace for more intervals, or bounce back faster between sets. Over weeks and months, that extra quality can add up.

Improved glycogen storage

When you take creatine with carbohydrates, and potentially protein as well, muscle creatine stores and glycogen levels both increase. Studies using combinations like 94 grams of carbohydrate per 5 grams of creatine or 47 grams of carbohydrate plus 50 grams of protein per 5 grams of creatine found enhanced muscle creatine storage and glycogen resynthesis through insulin stimulation (PMC).

More glycogen means more fuel for race day, particularly in long events or those with hard efforts late in the race.

Downsides and limitations to consider

Creatine is not a perfect fit for every endurance athlete. Understanding the tradeoffs will help you decide whether it belongs in your plan.

Weight gain from water retention

The most important downside for endurance athletes is weight gain. Creatine pulls water into muscle cells, which usually increases body mass by around 2 percent during a typical loading and maintenance protocol (PMC).

For non weight‑bearing sports like cycling and rowing, the extra mass may be offset by the power gains, especially for flatter or rolling courses. For weight‑bearing sports like running or trail racing, the additional weight can be a real disadvantage, particularly on hilly routes. A 2023 review noted that this mass gain may negate or even impair performance in some runners, while non weight‑bearing athletes are more likely to see a net benefit (PMC).

Modest or no effect on pure endurance

If your goal is only to improve your easy pace or time in a long, steady event with no surges, creatine probably will not do much. The 2023 systematic review that found little benefit for short‑term endurance performance in trained athletes under 35 highlights this limitation (TrainingPeaks).

Creatine shines when intensity goes up, not when you are cruising.

Safety, side effects, and common myths

Creatine monohydrate is one of the most studied sports supplements, and it has a strong safety record in healthy people.

A comprehensive review found that daily doses up to 20 grams for several days, followed by 1 to 10 grams per day for extended periods, did not harm kidney or liver function in athletes when monitored for up to 5 years (PubMed). Occasional reports of gastrointestinal upset and muscle cramps exist, but they are mostly anecdotal and have not been confirmed in controlled studies (PubMed).

Importantly, multiple studies have shown that creatine does not cause dehydration or muscle cramping. In fact, athletes supplementing with creatine experienced less cramping, less dehydration, and fewer heat‑related issues, along with improved hydration and thermoregulation (TrainingPeaks).

Still, because creatine increases the metabolic load on your kidneys and liver, especially at higher doses, regular monitoring is sensible if you plan to use it long term, or if you have any preexisting medical conditions (PubMed). You should always talk to your doctor before starting any new supplement, particularly if you have kidney or liver concerns.

How to use creatine as an endurance athlete

If you decide to try creatine, you will want a plan that fits your sport, your goals, and your timeline.

Typical dosing protocol

Most research uses a two‑phase approach:

Loading phase
Take about 20 to 25 grams per day, or roughly 0.3 grams per kilogram of body weight, divided into 4 to 5 smaller doses every 3 to 4 hours for 5 to 7 days.
Maintenance phase
After loading, take about 3 to 5 grams per day, or 0.03 grams per kilogram, to maintain elevated muscle creatine stores (PMC).

This protocol is what typically increases muscle creatine stores and body weight by around 2 percent.

If you are concerned about rapid weight gain before a race, you can skip the loading phase and take 3 to 5 grams daily for several weeks. It just takes longer to fully saturate your muscles.

Timing with your training

The exact timing of creatine during the day is not as critical as daily consistency, but there are some useful details.

A 2016 study found that taking 5 grams of creatine immediately after exercise led to greater gains in fat‑free mass and reductions in fat mass than taking it before exercise during a 4‑week resistance program (PMC). If you combine endurance training with strength work, taking creatine post‑workout is a reasonable choice.

Co‑ingesting creatine with carbohydrate or carbohydrate plus protein boosts muscle creatine storage. For example, taking 5 grams of creatine with 94 grams of carbohydrate, or with 47 grams of carbohydrate plus 50 grams of protein, significantly increased muscle creatine content, likely due to insulin‑mediated uptake (PMC). Practically, adding your creatine to a recovery shake or pairing it with a carb‑rich meal works well.

Best time to start

You will get the clearest read on how creatine affects you if you introduce it during a consistent training block, not right before an important race.

Consider starting:

In the base or early build phase, so you have weeks to assess effects
At least 4 to 6 weeks before a key event if you plan to use a loading phase
After discussing it with your coach or healthcare provider, especially if you already manage other supplements or medications

Is creatine right for your sport?

To decide whether creatine fits your needs, think about the demands of your primary events.

As a simple rule of thumb, the more your sport relies on high‑intensity surges and strong finishes, the more likely creatine is to help you.

You are more likely to benefit if you:

Compete in cycling, triathlon, rowing, mountain biking, cross‑country skiing, or swimming, especially events with repeated surges or sprint finishes (PMC)
Train with regular interval sessions that include short, hard efforts
Value better recovery and training quality, and you are not overly sensitive to a small weight gain

You may want to be more cautious if you:

Focus on long, steady, weight‑bearing events like marathons or ultramarathons on hilly terrain
Compete in categories where every kilogram of body mass is critical, such as steep mountain races
Have medical conditions affecting your kidneys or liver, or you are taking medications that could interact

If you are curious, a sensible approach is to test creatine in a lower‑stakes training block. Track your weight, interval performance, and how you feel during surges and sprints. Then decide whether the benefits outweigh the tradeoffs for your specific goals.

With a clear understanding of what creatine can and cannot do for you as an endurance athlete, you can make a more confident choice about adding it to your nutrition plan.