Do you need a creatine loading phase?

No. Loading (roughly 20g/day for 5-7 days) saturates muscle creatine stores faster, but a steady 3-5g/day dose reaches the same saturation point in about three to four weeks. Loading is a matter of how soon you want full saturation, not whether you reach it.

Does creatine cause kidney damage in healthy people?

The available trial evidence, including studies running a year or more at standard doses, has not shown kidney damage in healthy individuals. People with pre-existing kidney disease should ask a physician before supplementing, since most trials excluded that population.

Is creatine only useful for strength training?

No. Creatine's primary mechanism, faster ATP-PCr regeneration, benefits any repeated short, high-intensity effort: sled pushes, sprint intervals, and station-based race formats all draw on the same energy system, which is why it shows up as a relevant supplement for hybrid-format racing, not just powerlifting.

Supplements · Reviewed source list September 20, 2026

Creatine monohydrate: what the evidence actually supports

The most-studied supplement in sports nutrition is also the one hybrid athletes most often dose based on gym folklore rather than the trial data. Here's what the position-stand literature actually says.

By Thomas Prommer · Editor · 9 min read

Creatine monohydrate is, by volume of published trials, the most extensively studied ergogenic supplement in sports science. The International Society of Sports Nutrition's 2017 position stand, which reviews decades of that trial base, is the standard reference: it concludes creatine monohydrate is both safe and effective across a wide range of athletic populations when dosed within established protocols. That conclusion, and the specific dosing evidence behind it, is worth separating from the dosing habits that circulate informally in gyms.

What it does, mechanistically

Creatine supplementation increases muscle phosphocreatine stores, which speeds regeneration of ATP during short, high-intensity efforts (roughly 6-30 seconds of near-maximal output). This is why the strongest, most consistent trial effects show up in repeated-sprint and repeated-max-effort protocols, rather than in steady-state endurance performance, where the ATP-PCr system contributes comparatively little.

Loading versus steady dosing

Two dosing protocols appear in the literature, and both reach the same endpoint:

Loading protocol: approximately 20g/day (split into 4 doses) for 5-7 days, followed by a 3-5g/day maintenance dose. Saturates muscle stores within about a week.
Steady-dose protocol: 3-5g/day from the start, no loading phase. Reaches the same saturation point, just more gradually, typically within 3-4 weeks.

Neither protocol is more "correct." Loading front-loads the benefit; steady dosing reaches the identical maintenance state without the higher short-term dose. The ISSN position stand treats both as valid.

Timing: does it matter?

The trial evidence on pre- versus post-workout timing is mixed and, on balance, does not show a consistently meaningful difference. Because creatine works by building a saturated muscle store over days to weeks rather than acting acutely like caffeine, daily consistency appears to matter more than the specific clock time relative to training.

Safety: what the evidence shows and where it's limited

The ISSN position stand and subsequent reviews, including a 2019 systematic review and meta-analysis of renal function outcomes, have not found evidence of kidney damage from creatine monohydrate supplementation in healthy individuals at standard doses, including in studies running a year or longer. Two caveats worth stating plainly:

Most trials excluded people with pre-existing kidney disease, so the safety evidence does not extend to that population; anyone with known kidney disease should consult a physician before supplementing.
The evidence base is strongest for creatine monohydrate specifically. Other creatine forms marketed with efficacy or absorption claims (ethyl ester, hydrochloride, buffered forms) do not have an equivalent trial base showing an advantage over monohydrate.

Relevance to hybrid-format racing

Because HYROX-style formats include repeated short, high-intensity efforts (sled work, wall balls) layered onto an endurance base, creatine's mechanism is directly relevant to the strength-station portion of these races, even though it does nothing for the aerobic running component. It is one of a small handful of supplements (alongside caffeine) with a strong enough evidence base to be treated as more than a marketing claim.

FAQ

Do you need a creatine loading phase?: No. Loading (roughly 20g/day for 5-7 days) saturates muscle creatine stores faster, but a steady 3-5g/day dose reaches the same saturation point in about three to four weeks. Loading is a matter of how soon you want full saturation, not whether you reach it.
Does creatine cause kidney damage in healthy people?: The available trial evidence, including studies running a year or more at standard doses, has not shown kidney damage in healthy individuals. People with pre-existing kidney disease should ask a physician before supplementing, since most trials excluded that population.
Is creatine only useful for strength training?: No. Creatine's primary mechanism, faster ATP-PCr regeneration, benefits any repeated short, high-intensity effort: sled pushes, sprint intervals, and station-based race formats all draw on the same energy system, which is why it shows up as a relevant supplement for hybrid-format racing, not just powerlifting.