Abstract: Drinking bottle for sportspersons, having a case (1), a dome (2) with a drinking valve (3), a base (9) and a protective cap (4), wherein the drinking bottle comprises an insert (5) for preventing sloshing, such that (a) the insert (5) is a bag for receiving drinking fluid which is accessible via the drinking valve (3), wherein there is arranged beneath the bag (5) an expansion element (8) which is suitable for compressing the bag (5) in the direction towards the drinking valve (3) in dependence on the fill level; or (b) the insert (5) comprises multiple stages, which are interconnected; or (c) the insert (5) comprises a filling of a permeable, food-grade material having honeycombs or cells.