One of the key principles of training is overload. The overload principle states that body system adaptation fails to occur without an overloading stimulus. In other words, we have to give the body a challenge beyond what we are accustomed to in order to adapt to a higher level of performance. Somewhere along the way coaches started to think that we can only find overload in the weight room. In reality, for some qualities that is the last place we want to look. Maximum speed sprinting, for example, can provide overload in many areas that no other exercises can match.