Phinney [19] found

that in moderately obese, untrained subjects a prolonged exercise at 60% of VO2max can be sustained in the virtual absence of dietary carbohydrate (<10 g/d) for 6 wk with a surprising increase in treadmill time duration of 155% respect to baseline (from 168 to 259 minutes). In a second study [57], Phinney studied the effect of chronic ketosis on exercise performance in endurance-trained athletes finding that aerobic endurance FDA-approved Drug Library exercise by well-trained cyclists was not compromised by four weeks of ketosis. In contrast White suggested that VLCKD enhanced perception of fatigue during a 90 min walk, but in this study only RPE (Rate of Perceived Exertion) was significant whilst average heart rate and exercise intensity expressed at %HR max did not change. Unfortunately other performance indexes such as VO2max and blood lactate were not investigated [22]. More recently a broader study [18] www.selleckchem.com/products/MG132.html reported

that a ketogenic diet enhanced fat oxidation without detrimental effects on maximal or submaximal markers of aerobic exercise performance in obese subjects. Interestingly, to our knowledge, this is the first study published that measured the effects of VLCKD on strength performance and the authors reported no difference in strength isometric performance between VLCKD group and high carbohydrate group. Three factors should be taken into account to explain these conflicting results: 1) the time needed for keto-adapatation (approximately 7 days), 2) usage or not of electrolyte supplementation 3) the protein intake. According to the first factor, most studies have maintained the VLCKD for less than two weeks, which not sufficient to accomplish the full ketogenic metabolic adjustment (since

7 days are required for keto-adaptation leaving just a few days to see the effects of ketosis during these short dietary protocols). In our experimental design the ketogenic period was maintained for 30 days. Regarding adequate electrolyte supplementation Interleukin-2 receptor it is noteworthy that a supplement containing sodium and potassium is needed to maintain an effective nitrogen balance with functional tissue preservation [58] and the Tisanoreica® protocol reported here included an electrolyte supplementation [16]. Finally to maintain lean body mass a protein intake of 1.2–1.7 g/kg/bw with reference to body weight is required [58]. Most techniques used for weight loss in sports lead to a reduction of lean body mass with consequent negative effects on performance. The effects of the reduction in daily protein intake below 1.2 g/kg/bw during a VLCKD, includes the gradual loss of lean tissue and therefore the loss of physical performance as demonstrated by Davis [59]. The daily intake of protein during the ketogenic phase in our study was approximately 2.8 g/kg (assuming an increased protein requirement due to the very intense physical activity) [60, 61]. White et. al.