Introduction
daytime impairment, sleep disorders, sleep disturbance, Insomnia
Insomnia, defined by nocturnal sleep disturbance (e.g., difficulty falling asleep and staying asleep) and functional daytime impairment, is one of the most common sleep disorders [As several nutrients interact with neurotransmitters that help regulate the sleep–wake cycle, there is a growing interest in dietary strategies that promote sleep [The non-essential amino acid, glycine, is another nutrient that may improve sleep by activating Collagen peptides (CP) contain high amounts of glycine, as well as proline and hydroxyproline [Recent research suggests that athletic populations (e.g., student athletes, national, and elite level athletes) may sleep worse than the general population [