Sleep is linked to anabolic pathways [34] so how sleep disturbance affects metabolic pathways in young athletes needs to be considered. Dattilo et al. hypothesize a shift towards catabolic hormones during sleep debt contributes to muscle mass loss and a decrease in muscle recovery after exercise or injury [58].  Relevant to the pre-pubertal female athlete are malnutrition [29] and sleep deprivation which affect the anabolic growth hormone (GH) [59]. This evidence concerns the gene GH1 and malnutrition.