Effect of oat bran on time to exhaustion, glycogen content and serum cytokine profile following exhaustive exercise

The importance of dietary carbohydrates (CHO) in sporting performance was shown in the classical gaseous exchange experiments and biopsy studies, in which increasing exercise intensity utilises a greater proportion of CHO [1,2]. These data provided a major breakthrough for the science of sports nutrition, as it enabled the exact amount of CHO for athletes to be quantified.The recommendations concerning carbohydrates (CHO) for athletes are around 6 g-10 g/Kg/day [3-5] and these quantities vary in accordance with the quantity of body mass, gender, volume and intensity of the training. According to Tarnopolsky [3] elite athletes train around 8 to 40 hours per week, exponentially increasing their nutritional needs. The International Olympic Committee (IOC) recommends that: "following a diet rich in carbohydrates days before a competition can help to increase sporting performance, particularly when the exercise is kept up for longer than 60 minutes" [6].Exhaustive endurance exercise can induce immune disturbances and consequently increase susceptibility to upper respiratory tract infections [7]. Several mechanisms have been proposed in an attempt to explain the susceptibility of athletes to respiratory infections. Cortisol contributes only minimally to the exercise induced rise in liver glucose output [8], while it plays a role in immune disturbances [9,10]. Several components of the innate immune system are compromised during single or repeated sessions of exercise stress.Physical exercise can affect the levels of systemic cytokines, such as TNF-α [11-13], interleukin 1 beta (IL-1β) [12], IL-6 [12-16], interferon and others [11]. Recently, it has been suggested that the disruptions in the balance between pro- and antiinflammatory cytokines may lead to a loss of inflammatory control, with possible implications for overall immune system function [17,18]. The effect of ingesting carbohydrates during long duration exercises, with the purpose of attenuating immune suppressio