Why is cotton a better fabric for sports clothes than nylon?

Cotton is a better fabric than nylon for sports and exercise because, being a natural fibre, it breathes, meaning your skin can also breathe and sweat can evaporate like it is supposed to. This is similarly the case for wool. On the other hand, nylon is a synthetic polymer and hence does not absorb moisture well thereby can leave you feeling hot and clammy at the best of times, let alone during exercise and rigorous activity.