Likewise, our data are in opposition to the work of Jacobs and colleagues [12] who recently Ibrutinib manufacturer reported an improvement of 2.6-15% in high intensity cycle sprint performance with 4.5 grams of GlycoCarn® compared to a placebo. In this same study these investigators also noted an approximate 16% decrease in post-exercise blood HLa with GlycoCarn® compared to placebo. Differences in the exercise protocol likely contributed to the discrepancy in findings between the two studies. Finally, we have noted previously that GlycoCarn® results in lower resting MDA following chronic intake [14]. The present study extends those findings by noting a decrease, albeit statistically insignificant, in MDA from

pre- to post-exercise, indicating a potential antioxidant effect. Interesting to note, this favorable effect of GlycoCarn® on MDA reduction was associated with the highest StO2 at the start of exercise, indicating a possible association between increased blood flow and decreased lipid peroxidation. The converse was also true, as SUPP1 demonstrated the greatest increase in MDA from pre- to post-exercise, while displaying

the lowest StO2 at the start of exercise and the greatest drop in StO2 from the start to the end of exercise. These findings support the idea that exercise-induced hypoxia is associated with increased lipid peroxidation, likely due Deforolimus to increased free radical production [24]. It is possible that chronic treatment of GlycoCarn® may result in more robust changes in MDA or other markers of oxidative stress. Using a different stress protocol (handgrip dynamometry vs. resistance exercise), we have reported recently that four weeks of GlycoCarn® treatment at a daily dosage of 4.5 grams in resistance trained men results in a 45% decrease in oxidized to total glutathione ratio [40]. Additional work is needed to determine the antioxidant effect of chronic GlycoCarn®

administration following resistance exercise, and to determine whether or not such an effect translates into improved post-exercise recovery. One explanation for our lack of a performance effect for the chosen supplements, in addition to GlycoCarn®, could be our specific sample of BCKDHB subjects. That is, they may have been non-responders to treatment, as has been reported previously for a variety of sport supplements including caffeine [41], creatine [42], and GlycoCarn®, in terms of nitrate/nitrite [13]. If this were true, it is possible that a different group of subjects may have responded positively to treatment. This should be considered when athletes are contemplating the use of such products. For example, of our 19 subjects, 11 responded positively to GlycoCarn® in terms of total volume load, with a mean improvement above placebo of 12.6%. This is in opposition to the 3.3% improvement above placebo when including all 19 subjects in the analysis.