Fueling a swimmers performance is a very personal choice and to achieve the best outcomes for an individual needs to be a process of trial and error. For example there is no point buying expensive sports, protein or recovery drinks if the stay in the kitchen cupboard. Race day fuel needs to be food that has been tried and tested in the training pool.
The food medic
There's no need to panic and make drastic changes to your diet
Swimmer nutrition | Advice and meal ideas for swim parents
Nutrition for sports and exercise