Energy Needs Assessment And Performance Implications In United States Navy Explosive Ordnance Disposal Dive Recruits

Military divers are highly trained warfighters who perform various underwater operations. Dive training is physically intense, requiring adequate energy intake to support performance; however, evidence on energy balance in this group is lacking. PURPOSE: This research aimed to quantify the energy needs of United States Navy Explosive Ordnance Disposal (EOD) recruits throughout training. METHODS: Dive recruits were enrolled (n = 40) at Recruit Training Command Great Lakes, Illinois, during the first week of preparatory/selection (prep/select) courses and observed for 7 days. Baseline measurements included height, body weight (BW), and body composition/body fat percentage (BF%) via bioelectrical impedance analysis scale, and hydration status (via urine specific gravity); post assessments included BW and BF%. Doubly labeled water (DLW; 1.5 g/kg) was used to measure total energy expenditure (TEE), and wearables (Garmin Instinct) were used to track activity. Those who completed prep/select were tracked to dive school in Panama City, Florida, where the same course of measurements was repeated. Dietary intake was assessed via weighed food and digital photography during each training period. Two cohorts were recruited: winter (March/April 2024), and summer (July/August 2024). Winter cohort data (means ± SE or SD) are presented here. RESULTS: Participants were White (99%) males (n = 20, 22.9 years, prep/select; n = 13, 22.5 years, dive school) in the EOD dive training pipeline. At prep/select, there was a decline in BW (-2.9 ± 0.3 kg; p < .001), BF% (-1.7 ± 0.3%; p < .001), and lean body mass (LBM; -1.3 ± 0.4 kg; p = .003). At dive school, no change in LBM was detected but there was a decline in BW (-0.8 ± 0.3 kg; p = .03) and BF% (-1.5 ± 0.4%; p = .002). TEE from wearables was 3605.3 ± 1278.4 and 3042.5 ± 627 kcal/d, at prep/select and dive school, respectively. TEE measured via DLW was 5253 ± 171 and 4556 ± 247 kcal/d at prep/select and dive school, respectively. Preliminary dietary data (n = 14) at prep/select show an energy deficit of 2348 ± 1009 kcal/d (intake = 2889 ± 547 kcal/d). Observations included underconsumption at prep/select and a mismatch of meal timing to training at dive school. CONCLUSIONS: Data will be used to provide recommendations on military diver-specific policy for injury prevention and performance optimization. Supported by: I am a military service member or employee of the U.S. Government. This work was prepared as part of my official duties. Title 17, U.S.C. §105 provides that copyright protection under this title is not available for any work of the U.S. Government. Title 17, U.S.C. §101 defines a U.S. Government work as work prepared by a military service member or employee of the U.S. Government as part of that person’s official duties. The views expressed in this work are those of the authors and do not necessarily reflect the official policy or position of the Department of the Navy, Department of Defense, nor the U.S. Government.