Samples collected in subjects after creatine supplementation (postCRE) were compared to samples collected from placebo group (both before and after supplementation, prePLA, and postPLA, respectively) and from subjects before creatine supplementation (preCRE). Discussion Creatine has long been credited as an efficient ergogenic supplement that improves the anaerobic power of athletes submitted to high-intensity, short-duration tests [1, 3]. The metabolic strategy is supported Apoptosis inhibitor by the previous creatine overload in muscle fibers (particularly type-II) and enhancement of ATP generation

for extra power output during early/anaerobic stages of exercise. The maximum anaerobic https://www.selleckchem.com/products/3-methyladenine.html power was significantly increased by 10.5 % after acute 20 g/day creatine supplementation (Table 2), together with strong tendencies for increased

total workload and reduced fatigue index, although not see more significant in the present study. However, creatine has also been shown to have a role as an antioxidant compound that hampers overproduction of harmful reactive oxygen species (ROS) within contractile skeletal muscles during exercise [6, 32]. This hypothesis is in line with recent findings by Sestili et al. [33] who demonstrated that creatine treatment can directly prevent cell death in C2C12 myoblasts due to its antioxidant activity. Regarding mechanisms, due to its substantial absorption and dose-dependent accumulation in plasma following supplementation [34], creatine is supposed to exert a direct scavenging effect against ROS produced in plasma – with concomitant minor chelating action [7] – that enhanced blood antioxidant capacity in creatine-fed subjects (FRAP, Table 1). Neither

creatine itself nor any Erastin of its metabolites (e.g. creatinine) were directly measured here. Therefore, we cannot exclude the hypothesis of a co-adjutant chelating role of one of the creatine metabolites in plasma following its acute supplementation. Further studies are necessary to better address this hypothesis. Iron ions are reportedly released in plasma during/after strenuous exercise, but intracellular or plasmatic sources are still relatively obscure [18, 19]. Regarding total iron released in plasma (AUCt0-t60 ), creatine supplementation resulted in higher amounts released during/after 60 min of the exhaustive Wingate test (2.4-fold higher; Figure 1A and B). However, the same 2.4-fold higher iron content was also observed in creatine-fed subjects at rest, with lower increment from heme-iron (t0 post/t0 pre, Table 1). Thus, it is tempting to suggest that the pre-acquired increased iron content in plasma during the creatine supplementation period was responsible for a similar increase during/after exercise, indicating that no other source was mainly contributing to the total iron load in plasma during exercise.