001, Table 3). ECr presented higher urinary creatinine when compared to that of the second week (P < 0.05). There were no differences between exercised and sedentary animals in the sixth week. However, the exercised animals presented lower urinary creatinine when compared to those of the second week (P < 0.05). Concerning supplementation, it was verified that the creatine and creatine plus caffeine groups exhibited higher creatinine as compared to the caffeine groups (P < 0.001 and P = 0,001, respectively). In addition, the creatinine levels of the creatine group were lower than those in the second week. The caffeine groups also presented lower creatinine than those in the first week (P <

0.05). see more Discussion Selleck PS341 We demonstrated that supplementation with high combined doses of creatine and caffeine did not affect the LBM composition of either sedentary or exercised rats. However, caffeine supplementation alone reduced the percentage of fat in the carcass. In addition, the employed model of power training increased the percentages of water and protein and reduced the fat percentage in rats. One of the main observations of our study was that animals supplemented with creatine or creatine plus caffeine did not present

increased water retention in skeletal muscles (carcass). It is suggested that creatine supplementation leads to intramuscular water accumulation caused by its high osmotic power [7, 33]. Our results do not corroborate such hypothesis and are consistent with the similarity of body weight among our experimental groups as an increase in water retention in response to creatine ingestion might have augmented body

weight [13, 34]. Even though the methods of weighing were indirect, this lack of increase in body weight caused by creatine supplementation has been reported elsewhere [2, 11, 29]. Despite the fact that caffeine exerts a slight diuretic effect [15], which could have reduced water content, contrasting the effects of creatine [35], our study revealed that caffeine ingestion did not affect the percentage of water in the lean body TCL mass. Similar results were found by Vanakoski et al. [36], although in our experiment, caffeine dosage was 2.14 times higher. Concerning exercise effects, we observed an increased percentage of water in the carcass of the exercised animals. Although we have not assessed the content of muscle glycogen, it is thought that such effect is associated with the ability of exercise to promote accumulation of muscular glycogen, since 2.7 g of water are incorporated in the muscle per each gram of glycogen incorporated [37]. Our results agree with those reported by Cortright et al. [38]. Our observation that creatine or creatine plus caffeine did not affect the protein percentage of lean body mass demonstrates the absence of differences in body weight among our experimental groups.