However, contrary to carbohydrates, there is no evidence indicating that the increase of fat intake improves exercise performance . The stores of fat in the human body are so large and they will not become depleted after prolonged AZD2281 cost events such as 24-hour competitions
. Thus, there is no evidence to justify that the current cyclists would increase the amount of fat intake during the event. Nevertheless, the inclusion of fat in the diet of ultra-endurance events could be interesting, not to provide caloric dense options, but to satisfy the taste of foods . Fluid balance and caffeine intake The volume of fluid ingestion during bouts of exercise was in accordance with the recommendations for longer events . However, the composition of fluids was not in accordance with these guidelines . While these riders CHIR-99021 purchase ingested high amounts of water, they should have prioritized the consumption of hypotonic fluids containing carbohydrates, such as sucrose, maltose or maltodextrin at ~3-8% weight/volume, and sodium concentration of between 30 and 50 mmol/L . The consumption of these beverages is interesting in order to reduce dehydration and weight losses. In this study, the body mass of the riders decreased significantly after the race being this reduction more important in the second half of the event compared with the first 12 hours. However,
it is worth to mention that all body mass AZD8931 clinical trial Gemcitabine cell line reduction cannot be related to fluid losses, since we found no relationship between body weight losses and fluid ingestion. From this viewpoint, there is evidence that other factors such as loss of fat mass, skeletal muscle mass, glycogen and water stored in glycogen could also account for at least 2 kg of body mass loss [40, 41]. Thus, and according to the high energy deficit in the present cyclists, it could be also suggested that a considerable amount of body weight
loss was derived from losses of their endogenous energy stores. Unfortunately, we did not record urine output during the study. These data might have provided more detailed information about fluid balance and the origin of body weight loss. In addition, the use of sweat patches could be very interesting to analyze electrolyte losses in future investigations. Products rich in caffeine such as caffeinated beverages, coffee and caffeinated sport gels were consumed especially during the second half of the event when fatigue symptoms were more pronounced. Doses of caffeine between 1.5 and 3.5 mg/kg-1 body mass have been reported to enhance power output in laboratory studies . Although, caffeine has been also linked to diuretic effects , it seems that moderate doses (< 460 mg) of caffeine, do not induce water and electrolyte imbalance or hyperthermia . In this study, all the subjects consumed amounts of caffeine below this threshold during the event.