|If you put some faith into the marketing campaigns of supp producers, there's a creatine for everyone: one to get lean, one to get strong and one to get big and buffed... bullocks!|
How come? Well, the previously mentioned, as of yet unpublished data from a study by Ralf Jäger, Martin Purpura, and Roger C Harris did not just confirm the results of previous studies, which indicate that glucose (75g) and alpha lipoic acid (ALA | 200mg) will increase the bioavailability of creatine, i.e. "the proportion of a drug or other substance [in this case creatine] that enters the circulation when introduced into the body" (Merriam-Webster.com), it also indicates that the practically relevant predictor of creatine's efficacy is - assuming equal dosing and complete absorption - not a high, but rather a low level of creatine in the blood.
What? Let me explain: Initially, it may be worth pointing out that we are talking about a small scale study the results of which have not yet been published in the peer-reviewed journal. In that study, Jäger et al. aimed to compare the effects of ingesting tricreatine citrate (5g, TCrC),
- in combination with 75g of glucose and 200mg of alpha-lipoic acid, or
- without the former bioavailability enhancers.
|Figure 1: Mean plasma creatine concentration over 8 hours following ingestion of 5g tricreatine citrate (TCrC) and 5g tricreatine citrate + 75g glucose + 200mg alpha-lipoic acid (TCrC+Glu+ALA | Jäger. 2016).|
Less creatine in the blood with sugar + ALA? That's bad, right? No that's good!
Just as the likewise lower 0.5 and 1h plasma concentrations of creatine, in the TCrC+Glu+ALA group (in comparison to TCrC), these reductions do not indicate a reduced efficacy of the supplement. On the contrary! The significantly elevated mean 8h urinary creatine elimination in the control group (TCrC | 26.5 ± 13.9% of the dose administered vs. 17.2 ± 13.0% for TCrC+Glu+Ala) rather indicates that the addition of glucose and ALA "enhanced rate of creatine uptake into the muscle" - as previous studies indicate probably due to the presence of raised insulin (by glucose) and / or an increased insulin sensitivity (by ALA / Koszalka. 1972; Steenge. 1998; Pittas. 2010).
- Burke, Darren G., et al. "Effect of creatine and weight training on muscle creatine and performance in vegetarians." Medicine and science in sports and exercise 35.11 (2003): 1946-1955.
- Jäger, Ralf, Martin Purpura and Roger C Harris. "Reduction of Plasma Creatine Concentrations as an Indicator of Improved Bioavailability." Upublished data from privatt conversation (2016).
- Koszalka, Thomas R., and Carole L. Andrew. "Effect of insulin on the uptake of creatine-1-14C by skeletal muscle in normal and X-irradiated rats." Experimental Biology and Medicine 139.4 (1972): 1265-1271.
- Pittas, G., et al. "Optimization of insulin-mediated creatine retention during creatine feeding in humans." Journal of sports sciences 28.1 (2010): 67-74.
- Steenge, G. R., et al. "Stimulatory effect of insulin on creatine accumulation in human skeletal muscle." American Journal of Physiology-Endocrinology And Metabolism 275.6 (1998): E974-E979.
- Taylor, Lem, et al. "Effects of combined creatine plus fenugreek extract vs. creatine plus carbohydrate supplementation on resistance training adaptations." Journal of sports science & medicine 10.2 (2011): 254.