Kids are not just smaller adults, kids are the future. One great example of the differences existing between adults and both children and adolescent is represented by physical activity and training. Children and adolescent can't be trained as smaller adults and it is important to invest on kids the effort and the attention that they deserve. Being aware of the differences existing between biological and chronological age is particularly important when training the youngers. In order to train well young people it is important also to be aware of the windows of trainability as these are unique opportunities. The above mentioned information drives part of the training process. Treating kids as smaller adults does not enable children and adolescents to express their potential at the best, while recognizing their needs is the first step to increase the quality of the delivery.