Research: to load creatine or not

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Creatine monohydrate, after protein, is the most popular supplement for increasing strength and muscle mass. Various articles have been written about the effects of creatine. Here, I want to delve more deeply into a recurring discussion about the way creatine should be used, specifically the necessity of the “loading phase”. Is this loading phase truly necessary to achieve the best results from creatine, or is it a tactic by the supplement industry to empty your container faster and thus sell more?

Research indicates that the loading phase does indeed add value. Strangely, it is actually the maintenance phase where you can save a few euros.

What is the purpose of creatine loading

First, a brief explanation about the function of creatine.

Creatine monohydrate is used as a supplement to enable the body to more quickly produce ATP, a crucial fuel for muscles and the brain. ATP stands for Adenosine Triphosphate. The energy provided by ATP is released when one of its three phosphate groups is detached, turning Adenosinetriphosphate into Adenosinediphosphate (ADP) and a separate phosphate group. The energy released can be used for muscle contraction but only lasts a few seconds due to the limited amount of ATP in the muscles. Fortunately, new ATP can be quickly produced thanks to the presence of creatine phosphate (CP), also known as ‘phosphocreatine’ (PCr). With the help of the enzyme Creatine Kinase, creatine phosphate then ‘donates’ the phosphate group to ADP, turning it back into ATP and thus able to provide energy again. Supplementing with creatine ensures more creatine phosphate is available to make new ATP, leading to a quicker availability of energy.

The loading phase of creatine is often recommended because it builds up the amount of available creatine phosphate faster, allowing you to benefit from its advantages sooner. In practice, this means taking a total of 20 grams of creatine per day, usually split over four doses (5 grams per intake), for 5-7 days. This loading phase is then followed by a “maintenance phase” of 5 grams per day to keep the level of creatine phosphate up.

Why not a creatine loading phase?

There are two reasons why some might question the necessity of such a loading phase. The first concerns the health effects of creatine supplementation. The second is financial. However, both should not weigh heavily.

As for health effects, there have been concerns about potential dangers to the kidneys and liver for years, but these have been repeatedly refuted in multiple studies. Both the amounts used in the maintenance phase (5 grams/day) and the loading phase (20 grams/day) have been shown not to cause side effects but do improve maximum strength.

I previously considered the possibility that the loading phase is recommended to sell more creatine. As a consumer, this doesn’t seem to be of huge importance, especially as we are emerging from a deep financial crisis. However, for the industry, it makes a big difference. Let’s do the math:

Assuming a month of 30 days, a loading phase of a week at 20 grams per day, and a maintenance phase of 5 grams per day:

With loading phase: (7 x 20 grams) + (23 x 5 grams) = 255 grams per month

Without loading phase: 30 x 5 grams = 150 grams per month.

That’s a difference of 105 grams. The loading phase therefore results in 70% more creatine being used. Conversely, this means without the loading phase, 41% less creatine would be sold.

Creatine is relatively inexpensive. For instance, looking at the price (excl. discount) of Creapure® creatine (high quality and purity), 500 grams costs €14.90. Calculated and rounded, the extra 105 grams used for a loading phase costs €3.13.

€3.13 per month isn’t much. However, from the industry’s perspective, it’s a different story. It was calculated that between 2000 and 2003 alone, $400 million worth of creatine was sold in the U.S. Seventy percent on $400 million obviously makes a significant difference. Not all creatine buyers may have adhered to the loading phase, but if we assume everyone did, without the loading phase, only about $236 million would have been spent on creatine. And that’s just in the U.S.

Although it doesn’t make much difference to my wallet, I still wanted to find out if I was being duped, so I continued to search for evidence that the loading phase is necessary. While not mandatory, it indeed adds value.

No effect or major effect creatine? Personal differences have a large impact.

It’s important to know to what extent creatine supplementation can increase the amount of creatine in the muscles. It appears there is a limit to how much this amount can be increased, depending on the existing levels among other factors. People who naturally have a high amount of creatine stored in their muscles seem to respond minimally to creatine supplementation because they are already near their limit. In contrast, those with naturally low levels can see an increase of 25% to even 50% through supplementation.

Creatine supplementation can be seen as a way to eliminate these natural differences. More importantly, it could mean that you gain little to nothing from creatine if you are a so-called non-responder because you are already at the maximum. In one study with 8 participants, the creatine amount increased by an average of 25% in five participants, while in three participants, the increase was only about 5% (see image “A”, persons 5,6 and 8). Thus, a significant percentage of people will experience much less effect from creatine.

In the images to the right, you see the percentage by which the amount of creatine in the muscles has increased in six individuals with different baseline creatine levels. The one with the lowest baseline saw an increase of about 55%, while for the one with the highest baseline, it was just over 10%.

The effects of a loading phase. Faster achievement of maximum creatine levels

Various studies have examined the effects of a loading phase. These included different loading protocols ranging from 20 to 25 grams per dose, 4 to 5 doses per day, for 5 to 7 days, all resulting in a total intake of about 100 grams or more. Other studies based the intake on body weight at 0.25 grams per kilo of body weight per day. The advantage here is that it takes into account personal differences in weight (though this says nothing about personal differences in stored creatine amounts). More muscle mass means more storage capacity for creatine and vice versa. If you weigh around 80 kg, this makes little to no difference compared to 20 grams per day. However, if you are a professional bodybuilder weighing a dry 120 kg, you would need 30 grams per day. In my opinion, calculating based on lean mass would be even better. If you weigh 150 kg due to severe obesity, you do not have a higher storage capacity for creatine, as it is mainly stored in muscle mass, not body fat.

In all studies with a loading phase, researchers found that at the end of this 5-7 day phase, the total amount of creatine in the muscles had increased by an average of 20-30%. A loading phase of 3 days was found to have no effect in a 1996 study.

In studies that also worked without a loading phase, 3 grams per day for 28 days and 7.7 grams for 21 days ultimately led to the same results as with a loading phase. However, without the loading phase, it took longer to achieve these results.

“A similar, but more gradual, 20% increase in muscle total creatine concentration was observed over a period of 28 days when supplementation was undertaken at a rate of 3 g/day. In conclusion, a rapid way to “creatine load” human skeletal muscle is to ingest 20 g of creatine for 6 days.”

– E. Hultman, University Medical School, Queen’s Medical Centre

Swedish researchers saw that 3 grams per day on day 14 (table 2) led to a slightly smaller increase in stored creatine than what the loading phase had achieved by day 7 (table 1). In table 1, you see group 1 and 2 both having a loading phase of 20 grams per day (the difference was in the maintenance phase, see further) and in table 2, you see group 3 who had no loading phase. They calculated 3 grams as the daily dosage because this would be more than the daily breakdown of creatine (into creatinine).

Simply put, the loading phase of a week also means that results are achieved a week earlier. Whether it’s really that simple, I wonder. Unfortunately, the researchers do not show what the level was after 7 days of 3 grams per day. It’s possible that the level had already been reached that was shown after 13 days. However, this doesn’t seem very likely given the development of the level from day 14 to 29.

“Two grams of creatine per day sufficient for maintenance phase”

As mentioned, 5 grams per day is often recommended to maintain the increased levels. The researchers from Sweden examined whether 2 grams would suffice. They calculated 2 grams as the daily dosage for maintenance because this would correspond to the daily breakdown of creatine into creatinine.

In the images to the right, you see group 1 and 2. Both received the same loading phase. Group 2 also received a maintenance phase of 2 grams per day while group 1 received a placebo during this period. In group 1, which received a placebo during the maintenance phase, you see that the creatine levels quickly began to fall back to their initial values. In group two, thanks to the 2 grams of creatine per day, the levels remain constant.

The maintenance phase is indeed necessary to keep the level high, but it turns out 2 grams are enough instead of the commonly recommended 5 grams per day. So, the loading phase doesn’t unnecessarily benefit the supplement industry, but you can apparently save on the maintenance phase. However, don’t expect to save enough for a new car as we’re talking about a saving of 3 grams per day x 23 or 24 days. That amounts to just over €2 per month based on the previously mentioned prices for Creapure creatine at Body&Fitshop. Moreover, creatine is almost always supplied with 5 gram scoops, making exact measurement of 2 grams difficult. You could choose to use just half a scoop during the maintenance phase.

Conclusion

The loading phase of creatine monohydrate ensures you start benefiting from the creatine sooner. Maximum stored creatine levels are reached with a loading phase after 5 to 7 days, while without a loading phase, this probably takes an additional week. The maintenance phase is important for maintaining the increased levels. However, it appears that 2 grams per day is sufficient instead of the usually recommended 5 grams per day.

Finally, the effectiveness of creatine is always dependent on your personal creatine levels. This could mean that creatine is hardly of added value if these levels are already near their maximum, and that creatine levels can increase by more than 50% when they are naturally very low.

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