Intrinsic motivation is that which comes from within yourself. This includes your personal goals, interests, achievements, dreams, etc. On the other hand, extrinsic motivation is derived from the outside. This often includes items such as money, a career, a competition, a medal, etc.
It is better to rely on instrinsic motivation because this comes from you only. On the other hand, extrinsic motivation is derived from the outside world. This means that, if circumstances were to change, the motivation would be gone.
One way to enhance intrinsic motivation in participants of sports is by encouraging them to be self-aware and engaging in a process of self-knowledge. In this way, they will be more able to understand themselves, as well as their motivation and dreams.