For training, many middle distance runners will use a good pair of trainers for their steady runs and warm-up and warm downs. Although, generally, you get what you pay for, it is certainly not necessary to spend a fortune on them. Pick a pair which are comfortable and have good cushioning and supports. If you are prone to injury - getting advice on trainers may be useful as some are designed for those who either over or under pronate.

Photo Running Shoes

For the sessions themselves, often they will wear spikes for shorter quicker sessions, however for longer more endurance based sessions often athletes will have a pair of running flats they can wear. Flats are much lighter than normal trainers but with less support, allowing you to run quicker than in a normal trainer but providing slightly more support than a running spike (they are also kinder on the legs and don’t lead to as much stiffness the following day!).