Wednesday, April 27, 2011

XS® Energy Drink Practically Useless for Athletes: Not Even eXtra Small Improvements in Exercise Performance

XS Energy Drink. 0 sugar, only 83mg caffeine.
Probably tasty, but not ergogenic.
If you believe the marketing campaigns of supplement manufacturers (and, of lately energy drink producers), performance - just as about everything in our society - is for sale (in this case at the local GNC). You, as a regular visitor to the SuppVersity are yet aware that supplements, if they do work at all, usually provide a rather minute performance increase that - and here is where the magic happens - may nevertheless decide a head-to-head finish in your favor. It is thus very expedient that XSBlast refers to this X-tra S-mall advantage of their product line in their company name already... wait! You think they imply "XS" as in eXceSs? Well, I guess in the end it does not really matter, because their XS® Energy Drink, a mixture of 83mg caffeine, 1.5 g taurine, 6.0 mg Vitamin B6, 294 µg Vitamin B12, 10 mg Vitamin B5, 20 mg Vitamin B3, 24mg Sodium, 25mg Potassium, as well as undisclosed amounts of L-Glutamine, Citric Acid, an Adaptogen Blend (Eleutherococcus Senticosus, Panax Ginseng, Panax Quinquefolium, Schisandra, Astragalus, and Reishi), Natural Flavors and the artficial sweetener Acesulfame, does not seem to come up to any of these implications.

Supported by an independent research grant, K.M. Sheehan and L.K. Hartzler from the Department of Biological Sciences at Wright State University, Dayton, OH, USA, investigated in a double-blind cross-over study protocol (Sheehan. 2011) the effect of a single serving of XS® Energy Drink on subsequent exercise performance of 12 athletes (sex: 9m, 3f; age: 18-24 y) in a modified Ellestad Treadmill protocol and found:
Vo2max (p=0.99), time to muscle fatigue (p=0.48), maximum heart rate (p=0.66), [minute ventilation  max] VEmax (p=0.10), time at which [respiratory exchange ratio] RER is greater than 1 (p=0.50), or recovery time to one half Vo2max (p=0.67) were not significantly different with ingestion of XS® Energy Drink over placebo. 
Accordingly, the conclusion of the scientists, that "[e]ven with all sources of error taken into account it is still not likely that acute consumption of XS® Energy Drink, in the amount used in this experiment, has an advantageous performance effect" is valid for the whole spectrum of effect sizes from XS as in eXtra Small to XS as in eXceSsive ;-)

In view of some of the proclaimed ergogenics in the drink and the load of B-Vitamins having a possible effect on cognitive performance, as well, I would really like to see a study into these effects of this drink. Maybe, this is where the XS® Energy Drink produces eXceSsive results, after all.