The short version
- Muscle total creatine rose about 20% after six days at 20 g a day, and by a similar amount over 28 days at 3 g a day, in the same 1996 study of 31 men.
- After a load, muscle creatine was maintained on just 2 g a day, and 30 days after stopping entirely it was no different from the pre-supplementation value.
- In three subjects taking 6 x 5 g of creatine a day, muscle uptake was greatest in the first two days at 32% of the dose, while renal excretion over the first three days was 40%, 61% and 68%.
- In 59 soccer players over 28 days, diarrhoea was significantly more frequent on a single 10 g serving than on two 5 g doses (55.6% versus 28.6%), and the split dose did not differ from placebo.
- The ISSN position stand reports that creatine supplementation of up to 30 g a day for five years is safe and well tolerated in healthy individuals.
The instruction on the back of most tubs is a fortnight old before anyone questions it: twenty grams a day for five to seven days, then five grams a day forever. It is presented as a protocol. It is really a preference, and the study everyone is quoting says so in its own abstract.
The 1996 experiment that settled the arithmetic
Hultman and colleagues gave 31 male subjects creatine in different quantities over different time periods and biopsied the muscle. Total creatine concentration rose by approximately 20% after six days at 20 g a day, and that elevated level was then held when intake dropped to 2 g a day for a further 30 days. In a separate arm, a similar but more gradual 20% increase appeared over 28 days at 3 g a day. The authors' own conclusion is the least ambiguous sentence in the creatine literature: ingesting 3 g a day is, in the long term, likely to be as effective at raising tissue levels as the higher dose.
So the two protocols do not lead to different muscle. They lead to the same muscle on different dates. Loading is a way of buying about three weeks.
What loading costs to buy those weeks
The first cost is waste. Harris and colleagues, four years earlier, tracked where the creatine actually went in subjects taking five 5 g doses or more per day. Uptake into muscle was greatest during the first two days, accounting for 32% of the dose administered in three subjects on 6 x 5 g a day. Over the first three days renal excretion in those subjects was 40%, 61% and 68% of the dose. Past a point, the muscle stops accepting and the kidneys handle the rest — you are paying for creatinine.
The second cost is your gut, and it depends on how you split the dose rather than on the total. Ostojic and Ahmetovic gave 59 top-level male soccer players either 2 x 5 g daily, a single 10 g serving, or placebo for 28 days. Diarrhoea was the most frequent complaint overall at 39%. There was no significant difference in gastrointestinal symptoms between the split 5 g protocol and placebo — but diarrhoea was significantly more common in the single-10 g group than in the split group (55.6% versus 28.6%) and more common than placebo (55.6% versus 35.0%). Their conclusion was that 10 g a day in two equal doses shows no detrimental effect on the gut, and that the risk rises with a large single serving. Anyone loading by taking 20 g in one go at breakfast is running the version of the protocol most likely to fail.
Who loading is actually for
Harris found the increase in total creatine was greatest in subjects who started with a low content, raising them closer to the upper limit of the normal range — in some cases by as much as 50%. Diet is the main reason someone starts low: a single 5 g dose, the same paper notes, corresponds to the creatine content of 1.1 kg of fresh uncooked steak, which is a fair summary of why people who do not eat meat have the most room to fill.
Beyond that, loading earns itself when there is a deadline — a competition, a testing week, a training camp inside the next fortnight. If there is no date on the calendar, you are choosing between arriving in one week and arriving in four, at the same destination, and only one of those routes involves measuring powder four times a day.
The part nobody puts on the tub
Hultman also followed what happened when supplementation stopped. Without the 2 g maintenance dose, total creatine declined gradually, and 30 days after cessation the concentration was no different from the pre-supplementation value, with urinary creatinine excretion correspondingly increased on the way down. That reframes the whole question. Loading is a decision about one week of your life. Whether you still take it in March is the decision that determines whether any of it mattered.
On safety, the ISSN position stand is about as unhedged as position stands get: short and long-term supplementation, up to 30 g a day for five years, is safe and well tolerated in healthy individuals and in patient populations from infants to the elderly. That is not a licence to take 30 g. It is context for the fact that the standard 5 g is nowhere near any interesting boundary.
What we'd actually tell you
Skip the load. Take 3 to 5 g a day, every day, and start counting from week four rather than week one. If you do want to load — a deadline, or a diet with little meat in it — split it into four 5 g doses across the day rather than one large serving, and drop to a maintenance dose after about six days.
Two things this decision does not affect. It does not change the ceiling, only the date you reach it. And it does not make creatine an acute pre-workout ingredient, which is why finding 2 g of it on a pre-workout label tells you more about the marketing department than about the formulation. Beta-alanine sits in the same category and gets the same treatment: both are saturation ingredients pretending, once a day, to be stimulants.
Good questions
How long does a creatine loading phase take?
About six days at 20 g a day, split into four servings. That produced roughly a 20% rise in muscle total creatine in the 1996 study everyone cites. The same 20% appeared over 28 days at 3 g a day with no loading at all. So the loading phase is a three-week head start, not a different result, and it is entirely optional.
Will loading creatine upset my stomach?
It can, and how you split the dose matters more than the total. In 59 soccer players taking creatine for 28 days, diarrhoea affected 55.6% of those taking a single 10 g serving versus 28.6% of those taking two 5 g doses, and the split-dose group did not differ from placebo. If you load, take four separate 5 g servings across the day rather than one large scoop.
What happens if I stop taking creatine?
You drift back to where you started. In the 1996 study, muscle total creatine declined gradually once supplementation stopped and was no different from the pre-supplementation value after 30 days, with urinary creatinine excretion rising as it went. Nothing is lost that a few weeks of taking it again will not restore, but a month off is a month at baseline.
Can I take creatine only on training days?
It works less well, and it is not simpler. Creatine raises muscle stores over weeks and then needs a small daily intake to hold them there — 2 g a day was enough to maintain a loaded level in the 1996 study. Skipping four days a week means you spend part of every week drifting down. Take the same small dose daily and stop thinking about it.
Do vegetarians need to load?
They have the most to gain from supplementing, though not necessarily from loading fast. The 1992 study found the rise in total creatine was largest in subjects who started with a low content, and noted that a single 5 g dose corresponds to the creatine content of 1.1 kg of fresh uncooked steak. If you eat little or no meat you are likely starting lower and have more room to fill. Four weeks at 5 g a day will still fill it.
Does loading make creatine work better long term?
No. Both protocols in the 1996 study arrived at approximately the same 20% increase in muscle total creatine, and the authors concluded that 3 g a day is in the long term likely to be as effective as the higher dose. What determines your result twelve months out is whether you are still taking it, not how you started.
Sources
- Hultman E, Söderlund K, Timmons JA, Cederblad G, Greenhaff PL. Muscle creatine loading in men. J Appl Physiol, 1996. View study
- Harris RC, Söderlund K, Hultman E. Elevation of creatine in resting and exercised muscle of normal subjects by creatine supplementation. Clin Sci (Lond), 1992. View study
- Ostojic SM, Ahmetovic Z. Gastrointestinal distress after creatine supplementation in athletes: are side effects dose dependent? Res Sports Med, 2008. View study
- Kreider RB, Kalman DS, Antonio J, et al. International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. J Int Soc Sports Nutr, 2017. View study
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