66. EXAM QUESTION An athlete running a half marathon is offered a choice of drinks at a drink station at the 10-km mark of the race. The athlete has a choice of either a hypotonic, hypertonic or isotonic drink. Which drink would be the best choice at this point of the race? 1 mark b. Compare the three types of drinks and justify your choice in part a. 4 marks Isotonic SHORT ANSWER Hypertonic drinks have a high osmolality which which means that have a high carb concentration and are absorbed quite slowly. Hypotonic drinks have a very low osmolality and is absorbed very quickly, however it has a very low concentration of carbohydrates. Isotonic drinks have a similar osmolality to that of the body so are absorbed quite quickly. The athlete would have an isotonic drink because it would provide a balance of both rehydrating as well as refuelling the body.