For long-distance runners, a backpack must meet strict requirements: first of all, it must function as storage space for drinks and sources of energy to support the runner. What is more, athletes need to be ready for changeable weather conditions, night running, or the need to use a first-aid kit. This backpack can fulfil all these roles: it can contain anything that is necessary during running. Apart from meeting these requirements, the backpack ensures full comfort of movement. Its structure is based on a flexible frame made of fibreglass – thanks to that, the runner does not overburden his or her body, and the shape of the backpack makes it possible to rotate the spine freely. It guarantees a wide range of motion and good heat transfer.