It was assumed that the eccentric load of running led to rhabdomyolysis and therefore to an impaired renal function thus leading to a reduced water TSA HDAC concentration excretion as the reason for the accumulation of total body water. In a recent field study, the changes in body mass and fluid metabolism in Triple Iron ultra-triathletes covering

11.4 km swimming, 540 km cycling and 126.6 km running were investigated [7]. Unlike in a marathon, there is a change in sport disciplines in a Triple Iron ultra-triathlon and there is also a high eccentric stress situation due to the 126.6 km of running at the end of the race. The authors reported a decrease in body mass due to both a reduced fat mass and a reduced skeletal muscle mass but not due to dehydration. Furthermore, the development of oedemata after an ultra-endurance

performance, such as a Triple Iron ultra-triathlon, has recently been described in a case report [8]. These authors described a persistent increase in the total body water within 42 hours after finishing the race. They concluded, that the remarkably higher fluid intake during the race combined with an impairment of renal function buy Navitoclax due to muscle damage led to clinically visible oedemata of the feet, persisting for four days post-race. We may assume that comparable to the study from Milledge et al.[2] describing oedemata at the lower leg during the prolonged exercise of hill-walking, a Triple Iron ultra-triathlon also leads to oedemata at the lower leg. There are several different Phospholipase D1 mechanisms, which might lead to a retention of total body water. Maughan et al.[9] described an increased plasma volume following an increased protein synthesis. Mischler et al.[10] confirmed it in their study measuring the albumin synthetic rates as well as plasma volume and total body water before and after an ultra-endurance trial in six young men. They explained that due to its colloid osmotic properties, albumin mass expansion

is the major driving force for plasma volume expansion. On the Forskolin molecular weight contrary, Lehmann et al.[11] showed that protein catabolism could lead to hypoproteinemic oedemata. A further mechanism was reported by Uberoi et al.[12] describing that skeletal muscle damage with severe rhabdomyolysis could lead to an impaired renal function. Furthermore, due to an increased activity of aldosterone the Na+ retention increases [3] which therefore results in an increase in plasma volume [2, 13]. The quantification of changes in volume of body parts and the development of oedemata is a technical problem. There are different methods described in the literature for quantifying a change in limb volume. Lund-Johansen et al.[14] measured the displaced water by weighing whereas Bracher et al.[15] used plethysmography, which is quite similar to Lund-Johansen et al.[14] method with the difference that using plethysmography the displaced water is quantified as a volume.