Should you take creatine with carbohydrates?

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Taking creatine with carbohydrates is said to improve creatine uptake by the muscles according to research. But how many carbohydrates are needed for this and how long does this benefit last?

Creatine uptake

Yesterday, I showed, in the article “Does creatine work for everyone?” the results of a study from 1992 to illustrate that there are significant individual differences in the amount of creatine people absorb with supplementation. The same graph shows how much creatine the various participants in a study had stored in their muscles before and after creatine intake. In this case, measured in the vastus lateralis, one of the muscles trained in five of the participants (one leg, to be able to compare with the resting leg).

So the graph shows more than individual responses in terms of uptake. What I want to focus on today are the differences in maximum levels after creatine intake.

At the top of the result per participant, you see the number of days that creatine had been taken. You also have to take into account that different dosages were used. When you do that, the conclusion remains that there are differences in the maximum amount of creatine that the muscles of different people can store. Yesterday, for example, I mentioned the ratio of muscle fiber type as an important factor in this. Dry mass also plays a role (the results next to this are already expressed per kilo of dry mass).

Training also improves uptake, but I assume you’re already doing that. After all, that’s why you want to use creatine.

So what can you do yourself to absorb more creatine?

Taking creatine with carbohydrates

I ask that question because “improved uptake” is sometimes interpreted as if such a personal upper limit can be increased. There are studies showing that creatine is better absorbed by the muscles in combination with carbohydrates. This is said to occur because the sugars cause an insulin spike and insulin leads to better absorption [1,2]. The question, however, is whether this increases your maximum or only reaches it faster.

The research often cited in this context is that of Green and colleagues from 1996. Intake of 5 grams of creatine with 93 grams of simple sugars dissolved in water. In that study, it was not so much measured how much creatine was in the muscles, but how much creatine was excreted in urine. From the graph on the left, it can be seen that intake of 93 grams of sugars with 5 grams of creatine resulted in much less creatine being lost than without the carbohydrates.

These results are often translated as “taking creatine with carbohydrates increases creatine uptake by 60%”. That sounds good. It is fairer to say that taking creatine with 20 sugar cubes for three days results in 60% less creatine loss for three days.

Quite a lot of sugar needed

What does that 93 grams of sugar do to your body fat percentage? Let alone if you do that 4 times a day during a loading phase: 93 x 4 x 4 kcal = 1,488 kcal. Nearly one and a half thousand “empty” calories. Can’t it be done with a little less?

A study from 1998 has indeed shown that a significant increase in insulin is needed to absorb more creatine [2]. Two years later, the same researchers investigated alternatives. After all, protein can also raise insulin levels. They therefore compared the intake of 5 grams of creatine with 96 grams of carbohydrates or with 50 grams of protein and 46 grams of carbohydrates. This turned out to have the same effect on increasing insulin. It also resulted in 25% more creatine being retained in both cases.

So half as much sugar and instead welcome protein. A better method in my opinion.

A later study from 2003 has shown that even lower doses of sugars can improve creatine uptake. Researchers from Baylor University gave their participants four different supplements. I’ll just put the result right behind it:

1. 5 grams of dextrose (D) – increase in creatine retention 0%
2. 5 grams of creatine monohydrate (C) – increase in creatine retention 36.6%
3. 5 grams of creatine + 18 grams of dextrose (CD) – increase in creatine retention 48%
4. 5 grams of creatine mix (EC) – 5 g creatine + 18 g dextrose + 320 mg sodium + 175 mg potassium (EC) increase in creatine retention 37%

This was done for 3 days, 4 times a day. We see that adding 18 grams of dextrose increased the amount of creatine retained by the body by about 30%.

Reaching your maximum creatine level faster or reaching a higher level?

But what happens if you don’t load only once or for just 3 days? How close were these people to their maximum uptake? As asked before: do the sugars make you reach your maximum creatine level earlier or do they increase your maximum level? If 2 grams of creatine are enough to maintain your creatine level after loading, is it useful to find a way to get even more of those 2 grams into the muscles? After all, full is full you would think. Whether that thought is correct, I’ll come back to that.

It’s a pity that these studies were not conducted over a longer period. What’s especially interesting is to see how long carbohydrates provide added value and whether people who are already close to their maximum creatine levels can achieve higher levels. As far as I know, such studies have not been conducted. This leaves the question of whether adding sugars only shortens a loading period.

It’s also not handy that in this study we can’t see how much creatine the participants had in their blood before intake. So we can’t see to what extent this influenced uptake, or rather, the loss of creatine. Otherwise, you could divide the participants into groups based on this and within those groups see if the added sugars were beneficial and to what extent.

“Your maximum creatine level”

Studies on creatine uptake over the long term offer interesting insights. It turns out that creatine levels rise to a maximum level and then at some point drop again. Even with dosages that should be sufficient for maintenance.

If you see creatine storage in the muscles as a cup, there are various factors that determine how quickly that cup fills up and empties again. Apparently, at some point, it doesn’t matter how much you consume. Something causes it not to arrive in the same way anymore, or to drain faster.

In another study from 1998, it was found that creatine levels rise during supplementation for up to ten weeks before falling again [4]. In that study, however, training was stopped after 10 weeks (and creatine intake continued). We know that training has a positive influence on creatine uptake.

In a follow-up study from 2001, the same researchers observed that creatine levels measured in the vastus lateralis had increased after 2 and 5 weeks, but no longer after 12 weeks [5]. Similar results followed from a study from 1999 in which creatine levels were increased by 22% after a week of loading (25 grams/day) and only by 10% after 12 weeks [6].

Although it’s difficult to pinpoint the exact point, there is reason to believe that the maximum creatine level can only be temporarily maintained upon intake. Thus, there is a theoretical possibility that taking carbohydrates with your creatine could be beneficial at some point (again). However, this again assumes that carbohydrates can increase the (relative) maximum. This has never been proven in research, let alone after, for example, 10 weeks.

Conclusion

In the short term of a few days, combining creatine with carbohydrates leads to a greater uptake of creatine. The effect may vary depending on the amount and type of sugars. We have seen that not only a large amount of 93 grams of sugars can cause this, but also a combination where half of those sugars are replaced by protein. Even a smaller supplement of 18 grams of dextrose increased uptake.

However, the key question is whether these effects still apply when your maximum creatine levels have already been reached, or when maximum retention decreases over time. Research has not yet been able to clarify this.

Of course, carbohydrates after a workout also have their “own” function. However, when it comes to improving creatine uptake, I see only one proven advantage and one presumed advantage:

• The loading phase is shortened by a few days because the ingested creatine is better absorbed and reaches its maximum faster.
• Carbohydrates may possibly help maintain maximum levels after a few weeks. This is only theoretical.

So, a few days’ advantage and possibly again after a few months. Adding 20 sugar cubes to your creatine to benefit more from this does not seem wise. If you happen to already consume carbohydrates after your workout then it’s fine to combine.

References

1. Green, A.L., E.J. Simpson, J.J. Littlewood, I.A. MacDonald, and P.L. Greenhaff. Carbohydrate ingestion augments creatine retention during creatine feeding in humans. Acta Physiol. Scand. 158:195-202, 1996.
2. Steenge, G.R., J. Lambourne, A. Casey, I.A. MacDonald, and P.L.Greenhaff. Stimulatory effect of insulin on creatine accumulation in human skeletal muscle.Am. J. Physiol. 275:E974-E979, 1998.
3. Greenwood M, Kreider R, Earnest C, Rassmussen C, Almada A. Differences in creatine retention among three nutritional formulations of oral creatine supplements. J Exerc Physiol Online. 2003;6:37–43.
4. Vandenberghe K, Goris M, Van Hecke P, Van Leemputte M, Vangerven L, Hespel P: Long-term creatine intake is beneficial to muscle performance during resistance training. J Appl Physiol 83: 2055–2063, 1997
5. Hespel P, Op‘t Eijnde B, Van Leemputte M, Urso B, Greenhaff PL, Labarque V, Dymarkowski S, Van Hecke P, Richter EA: Oral creatine supplementation facilitates the rehabilitation of disuse atrophy and alters expression of muscle myogenic factors in humans. J Physiol (Lond) 536: 625–633, 2001
6. Volek JS, Duncan ND, Mazzetti SA, Staron RS, Putukian M, Gómez AL, Pearson DR, Fink WJ, Kraemer WJ: Performance and muscle fiber adaptations to creatine supplementation and heavy resistance training. Med Sci Sports Exerc 31: 1147–1156, 1999