TARFU: LaBrada Nutrition Financed Study Finds no Effect of Super Charge Xtreme N.O. on Training Induced Increases in Muscle Size. Minor Effects on 1RM Max.

As mentioned in previous blogposts, I highly credit all supplement companies which - instead of just putting out untenable claims about the "steroid-like" effects of their products - spend a few bucks of their immense marketing budgets on research on how fantastic their products actually are. In the case of LaBrada Nutrition's Super Charge Xtreme N.O. it does yet seem that it would have been wiser to do some research before formulating their new "NO booster".

Other than the guys over at LaBrada Nutrition probably have hoped or even expected, the study (JSCR. 2011) that was published in the March issue of the well-known Journal of Strength & Conditioning Research found no "significant improvements in LBM over the placebo drink" and only minor increases in bench press 1RM and squat power, which may well be attributed to CNS stimulation due to the hefty 450mg load of caffeine each serving of Super Charge Xtreme N.O. contains.

Other than that, the "15 physically active, resistance trained, college age (19.5 +/- 0.269 yr) males" in the placebo group attained the same changes in body weight, body [as measured via dual-energy X-ray absorptiometry (DEXA)] and maximal strength in the rest of the 8 different exercises of their 3-day/week exercise regimen:

A main effect for time was identified for each of the 1RM strength measures tested (p<0.05) except biceps curls (p = 0.34). [....] Significant main effects were found for lean body mass (F1/22 = 20.32, p<0.001), but there were no significant group x time interactions for changes in LBM (F1/22 = 0.142 p = 0.710).

But let's be honest. Did you still believe an NO booster will improve your gains? I, for my part, take them for the feeling of being pumped up. And although I have not yet had the chance to test this particular product, I am inclined to believe that it will provide similar results as the classics like NO Xplode & Co - that kind of cosmetic pump you either love or hate.

L-Citrulline Against Arterial Stiffness

You probably know it from the ingredient list of your pre-workout or amino acid product, l-citrulline. Being a possible precursor of l-arginine it is included in those formulas to increase nitric oxide levels and deliver those "skin bursting pumps" the advertisements brag about.

In a recent study, scientists from Japan (Ochiai. 2010) found that 1 week of l-citrulline supplementation at 5.6g/day effectively reduced arterial stiffness in 15 healthy males:

Compared with the placebo group, baPWV [index of arterial stiffness] was significantly reduced in the l-citrulline group (p<0.01). No significant differences in blood pressure (BP) were found between the two groups, and no correlation was observed between BP and baPWV. The serum nitrogen oxide (NOx, the sum of nitrite plus nitrate) and NO metabolic products were significantly increased only in the l-citrulline group (p<0.05). Plasma citrulline, arginine and the ratio of arginine/asymmetric dimethylarginine (ADMA), an endogenous inhibitor of NO synthase (arginine/ADMA ratio) were significantly increased in the l-citrulline group compared with the placebo group (p<0.05, p<0.01, p<0.05, respectively). Moreover, there was a correlation between the increase of plasma arginine and the reduction of baPWV (r=-0.553, p<0.05).

Beyond the reduction in arterial stiffness, these results confirm the hypothesis that l-citrulline effectively increases NO metabolism (probably even more than l-arginine) AND, what's even more important, reduces an endogenous inhibitor of NO synthase, so that more nitric oxide may be produced.