Creatine for Endurance: When Does It Benefit You?

In short: creatine helps you rapidly replenish ATP — the body's most explosive short-term fuel. ATP stands for Adenosine Tri-Phosphate and consists of an adenosine molecule with three phosphate groups. When one phosphate group splits off, energy is released, and ATP becomes ADP (Adenosine Di-Phosphate), which is an adenosine molecule with two phosphate groups.

Creatine in the body binds phosphate and forms creatine phosphate. Creatine phosphate acts as a quick rotating donor — when ADP is formed, creatine phosphate quickly donates a phosphate group, so ADP becomes ATP again. The result is that you can perform a few extra repetitions, sprint the last 20 meters, or push through uphill when your thighs are burning.

Having an extra layer of phosphate in the muscle cell allows us to recharge our explosive fuel faster and thus perform better in short, high-intensity moments.

Several dosing protocols have been studied in research. The commonly used and practical approach is:

• Loading phase: 0.3 g/kg body weight per day for 5–7 days. A simple guideline is 5 x 5 g/day for 5 days (for a person weighing about 82 kg), totaling 25 g per day during the loading week and 125 g in total.
• Maintenance dose: 0.03 g/kg body weight per day, which is approximately 2.5 g/day for a lighter person. In practice, 5 g/day is often recommended as it corresponds to a scoop and is easy to manage.

5 g/day is also the dose that research with high certainty considers safe to consume daily over a long duration.

Creatine monohydrate is the variant studied in about 95 percent of all research — it's also the most affordable and well-researched option (link). Other variants exist, but none have proven better than monohydrate in practical effect.

A quick look at other variants:

• Creatine citrate and CreaPure dissolve slightly better in water, but the effect in the body remains the same.
• Buffered variants like Kre-Alkalyn and creatine hydrochloride have shown effects equivalent to regular monohydrate in studies but are usually more expensive.
• Creatine ethyl ester should be avoided — it breaks down to creatinine (inactive) and does not have the same effect.
• Form (capsules, tablets, or powder) has no physiological role, choose what suits you practically.

Creatine Monohydrate, still the champion!

Avoid pre-mixed products where creatine might have been diluted for a long time and partially converted to creatinine, reducing its effect. This doesn't happen in a few minutes when mixing at home, but pre-mixed products might have become too old and are principally gone.

Unfortunately, creatine doesn't significantly impact endurance performance on its own — long-term running or cycling isn't noticeably enhanced by acute creatine supplementation (link). The reason is straightforward: endurance activities rely more on aerobic energy systems rather than the ATP/creatine phosphate system.

Nevertheless, creatine provides clear advantages through strength elements:

• Strength training progresses faster, yielding improved muscle strength and stability.
• Increased muscle mass and stability are linked to a lower risk of injury.
• Creatine can be particularly beneficial during high-intensity training periods, as it enhances recovery and enables muscles to produce more power in short, intense bursts — for example, on the treadmill, during hill intervals, in the Skierg, or on the trainer.

However, it's important to note that some studies don't show any effect during interval training or when combining intervals and strength training (link, link). So: it often works, but it's not a foolproof solution for all high-intensity training.

The most consistent evidence is found in pure strength training. Since strength training should be included in endurance athletes' training regimens, creatine can be a valuable supplement during base training when heavier strength work is typically undertaken.

When consuming higher doses of creatine, the cells retain extra fluid (approximately 0.7–0.9 liters). This cellular fluid accumulation triggers a stress response that in turn gives an anabolic signal and an “amplification” of the muscle cell. The extra swelling can also speed up glycogen storage (as mentioned in our previous article Optimized Recovery).

With the same amount of pure creatine in a product, it almost always retains the same amount of fluid. If a product claims to retain less water, it is usually because it is diluted with other substances — meaning a smaller proportion of pure creatine. Examples of creatine content in different variants:

• Creatine Monohydrate – 88% creatine (12% monohydrate)
• Creatine Ethyl Ester – 82% creatine
• Creatine Pyruvate – 60% creatine
• Creatine Alpha-Ketoglutarate – 54% creatine

I can't find a value for Kre-Alkalyn in the list above, but there is research comparing Kre-Alkalyn with regular monohydrate and shows no differences in effect — only in price.

• Take Creatine Monohydrate by following a loading phase of 5 x 5 g for 5 days (total of 125 g over the period).
• After that, maintain with 2.5–5 g/day during base training to boost strength development and speed up recovery.
• Creatine Monohydrate is affordable (around 200 SEK/kg) and is something we highly recommend during base training.