Effect of pre-sleep alpha-lactalbumin supplementation in a trained population with sleep difficulties

Study design - Randomised, double-blinded, counterbalanced, crossover design (Crossover experimental group = 40 g alpha-lactalbumin; Crossover placebo group = 40 g collagen) As a cross-over trial, to limit any potential carry over effects of the alpha-lactalbumin into the next intervention period, a minimum five night washout period is to be observed. Further, to ensure the influence of female hormones is low throughout the intervention periods (as this can confound sleep outcomes), naturally menstruating females are to complete both intervention periods during the early follicular phase. This phase will be determined through menses and menstrual cycle mapping. Experimental group - alpha-lactalbumin Product - BiPRO Alpha 9000 (Agropur Inc, Appleton, WI) Dose - 40 grams once daily Duration - 3 days Dosage form - Powder, oral Route of Administration - Oral Active ingredient - Tryptophan (1.9 g) To investigate the effect of evening supplementation (2 hours prior to sleep) of 40 g alpha lactalbumin the sleep, mood, and cognition of a trained population with sleep difficulties compared to placebo. Amino acid analysis and melatonin measured within blood plasma to explore potential mechanisms by which alpha-lactalbumin may influence sleep To control for protein's potential confounding influence on the effectiveness of alpha-lactalbumin supplementation, participants diet will be standardised to meet habitual energy intake, and 1.2 g/kg of body weight of daily protein. This amount is at the lowest end of recommended protein amounts for athletes. As participants will complete the intervention periods at the Deakin University campus, a member of the research team (or research assistant) will be providing both the supplement and meals to the participants. This means adherence to both the diet and supplement is able to be observed. Further, all meals (3 main meals + 2 snacks) will be provided by a member of the research team, with participants able to consume additional low-protein snacks if they wish to do so (must be replicated by the participant for both intervention periods). The dietary supplement will be mixed up and matched for taste by an external researcher, to ensure both participants and the researcher team remain blind to the treatments.