Pre-sleep Protein Supplementation Does Not Improve Performance, Body Composition and Recovery in British Army Recruits

Dietary protein is crucial for optimising physical training adaptations such as muscular strength and mass, which are key aims for athletic populations, including British Army recruits. New recruits fail to meet the recommended protein intake during basic training (BT), with negligible amounts consumed in the evening. This study aimed to assess the influence of a daily bolus of protein prior to sleep on performance adaptations, body composition and recovery in British Army recruits. The study will recruit a mixed cohort of >120 new recruits from the United Kingdom (UK) British Army who will be randomised into a dietary control (CON), carbohydrate placebo (PLA), moderate (20g) protein (MOD) or high (60g) protein (HIGH) supplementation group. Supplements will be isocaloric and consumed daily on weekday evenings between 2000 and 2100h for 10 weeks during BT, alongside standardised dietary intake and BT activities. Performance tests (mid-thigh pull, medicine ball throw, 2km run time, maximal push-up and maximal vertical jump) and body composition will be assessed at the start and end of BT under standardised conditions. Dietary intake, energy expenditure, salivary hormones, urinary nitrogen balance, perceived muscle soreness, rating of perceived exertion, mood and fatigue will be assessed at the start, middle and end of BT. The underlying aim of this study is to assess whether inclusion of nocturnal protein supplementation will influence performance adaptations, body composition changes or acute recovery in British Army recruits.