An Cosantóir

24 FUELLING THE NATION Napoleon is also accredited with saying "an army marches on its stomach", and "there is no subordination with empty stomachs". Both, of course had a point, and were basically saying that an army, or defence force, needs energy, and that energy comes from whatever that force consumes through their diet. Energy can be defined as the strength and vitality required for sustained physical or mental activity, or simply, the ability to do work. Terms used in relation to how our bodies use energy, are: • Energy Intake: This is the total amount of calories ingested through an individuals diet. • Energy Expenditure: amount of calories burned on any given day. • Energy Balance: When intake is equal to expenditure. • Energy Availability: This is the energy remaining for the body's physiological functions once physical activity has been accounted for. The energy extracted from our food, through various chemical processes is measured in kilojoules (kj), or more commonly, calories (kcal). We need a certain intake of energy each day in order for our bodies to function optimally, and also meet the energy requirements of any activity we engage in throughout the day. According to O Leary et al (2020), military personnel operate in prolonged energy deficits at different stages throughout their careers, especially when engaged in robust training on courses or field exercises, or deployed overseas in challenging environments, where their daily energy expenditure regularly exceeds intake. This can be due to prolonged intense activity, logistical constraints, sleep deprivation, insufficient food, and psychological stress, and will lead to low energy availability, which can have a number of negative health and performance implications. Robust courses such as the Infantry Platoon Sergeants Course (multiple consecutive FTX), spring to mind as well as a particular mission in Central Africa where evening nutrition in camp consisted of "biscuits brown" (which became like gold dust in our platoon lines), biscuits fruit", or "cut-price" bars of chocolate from the camp canteen. Spare ration pack meals would have been considered a luxury. Thomas et al (2016) state that an active individuals daily energy intake must be sufficient in order to ensure optimal health, and Article and Photos By Sgt Mick Lennon "An army, like a serpent, goes upon its belly". - Frederick the Great. training adaptations, and to avoid undesirable muscular atrophy, fatigue, illness, injury, and other associated physiological outcomes. The daily tasks of different military personnel vary in intensity from sedentary to prolonged high intensity. Tharion et al (2005) state how several studies of military personnel from various units, engaging in a range of activities, reported energy requirements ranging from 3,100-7,130 kcal. Nutrition should be tailored to the individual and taken into account daily variations in intensity and duration of physical activity, as well as any specific sport or event, training goals, and physical characteristics like height, weight, age, gender and fat free mass. Therefore, it is important that an individual is aware of their own specific day to day energy requirements in terms of total calories and relative amounts of macronutrients. Total daily energy expenditure (TDEE), is made up of three components: • Basal, or resting metabolic rate (RMR): 60-80% • Physical activity: 20-30% • Thermic effect of food (diet induced thermogenesis): When energy intake is equal to expenditure, this accounts for approximately 10% of daily energy expenditure (Westerterp 2004) Physical activity can be broken down further into: • Non exercise activity thermogenesis (NEAT). • Exercise activity thermogenesis (EAT). (Chung et al 2018). While the percentages above are primarily based on relatively inactive people, Thomas et al (2016) suggest that for elite athletes RMR can go as low as 38-47% with endurance athletes in particular having physical activity levels accounting for as much as half of their TDEE. Brewing up in Tchad. Rations heating on top of a Mowag overseas.

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