Of course, this is largely speculation, as has been discussed in more detail recently [16]. With regards to betaine and the potential find more for increasing nitric oxide, a study by Iqbal and colleagues found that daily supplementation at an oral dosage of 6 grams for 7 days, followed by a single serving on day 8 of 3 grams, had a profound effect (20-90%) on elevating blood nitrate/nitrite, a surrogate marker of nitric oxide [17]. Similar results were reported by Iqbal and coworkers in another study [18]. However, aside from these studies (available only as abstracts and within a US patent application [US 2007/2013399 A1],

and not in manuscript form), no published investigations have selleckchem focused on the effect

of betaine to elevate nitrate/nitrite. Therefore, the purpose of our work was to investigate the effects of orally ingested betaine in exercise-trained men (the most likely candidates for use of betaine as an ergogenic aid) using three different study designs (acute intake at two different dosages, chronic intake at one dosage, and chronic followed by acute intake–as to replicate the work of Iqbal et al.). We hypothesized that betaine ingestion would increase plasma nitrate/nitrite levels, in a manner consistent with the findings of Iqbal and coworkers [17, 18]. Methods EPZ5676 ic50 Subjects Subjects for all three studies were recruited from the University of Memphis Campus and surrounding community. Subjects were allowed to participate crotamiton in more than one study. However, this was only the case for a few of the subjects. Study 1 was completed first, followed by an approximate one month break before beginning Study 2. Study 3 was started approximately five months after the completion of Study 2. Subjects were not

smokers, did not have self-reported cardiovascular or metabolic disease, and were exercise-trained. Subjects were not using dietary supplements believed to influence blood nitrate/nitrite. That is, subjects were allowed to continue their normal intake of multi-vitamin/mineral supplements, as well as protein powder. Characteristics of subjects are presented in Table 1. Health history, drug and dietary supplement usage, and physical activity questionnaires were completed by subjects to determine eligibility. Subjects were instructed to maintain their current exercise and dietary intake programs throughout the study periods. However, in all three studies subjects were instructed to refrain from strenuous exercise during the 24 hours prior to each test session, and to avoid intake of nitrate rich foods (e.g., cured meats, beets, spinach). All studies were approved by the university committee for human subject research (H10-43; H10-44; H11-09) and all subjects provided written consent.