Pre-sleep Protein Supplementation and Load Carriage Recovery in British Army Recruits

Pre-sleep Protein Supplementation Does Not Improve Recovery From Load Carriage in British Army Recruits

Load carriage is a common military activity and has been shown to induce acute exercise-induced muscle damage (EIMD) and impair muscle function. Protein supplementation can accelerate muscle recovery by attenuating EIMD and muscle function loss. This study investigated the impact of an additional daily bolus of protein prior to sleep throughout training on acute muscle recovery following a load carriage test in British Army recruits. Muscle function (maximal jump height), perceived muscle soreness and urinary markers of muscle damage were assessed before (PRE), immediately post (POST), 24-hours post (24h-POST) and 40-hours post (40h-POST) a load carriage test.

British Army basic training (BT) is physically demanding with new recruits completing multiple bouts of physical activity each day with limited recovery. Load carriage is one of the most physically demanding BT activities and has been shown to induce acute exercise-induced muscle damage (EIMD) and impair muscle function. Protein supplementation can accelerate muscle recovery by attenuating EIMD and muscle function loss. This study investigated the impact of an additional daily bolus of protein prior to sleep throughout training on acute muscle recovery following a load carriage test in United Kingdom (UK) British Army recruits. A mixed group (men/women) over over 120 new recruits were randomised to dietary control (CON), carbohydrate placebo (PLA), moderate (20g; MOD) or high (60g; HIGH) protein supplementation. Muscle function (maximal jump height), perceived muscle soreness and urinary markers of muscle damage were assessed before (PRE), immediately post (POST), 24-hours post (24h-POST) and 40-hours post (40h-POST) a load carriage test. The underlying aim of this study was to assess whether additional protein intake could attenuate aspects of muscle damage from an acute load carriage test including muscle function, muscle soreness and biomarkers of muscle damage during short term recovery.

The participants received a 60g whey protein bolus each evening prior to sleep pre and post a military load carriage test.

The participants received a 20g whey protein bolus each evening prior to sleep pre and post a military load carriage test.

The participants received an isocaloric carbohydrate bolus each evening prior to sleep pre and post a military load carriage test.

The relative change in concentration of urinary myoglobin (ng/ml) in participants before and after the load carriage test

The relative change in concentration of urinary 3-methylhistidine (nmol/ml) in participants before and after the load carriage test

Inclusion Criteria: Enrolled into British Army basic training Medically fit to train and complete the load carriage test Exclusion Criteria: Not taking any other nutritional supplement Pregnant