The Navy SEAL Physical Fitness Guide - Uniformed Services ...

Terms Related to ConditioningMany terms are used to define or describe exercise conditioning and work rate, alsoreferred to as exercise intensity or work load. The two terms used throughout this chapterfor describing how to gauge your work rate will be maximal oxygen uptake and energyexpenditure as calories/hour, or kcal/hr. Other terms to describe work rate and theirinterrelationships will be discussed at the end of this chapter.Maximal Oxygen UptakeThe primary measure or predictors of one's capacity to sustain work performance ismaximal oxygen uptake (VO 2max ) or maximal aerobic (cardiorespiratory) capacity.VO 2max is measured in milliliters per minute (ml/min), Liters/min, or after adjusting forbody weight in kilograms, as ml/kg/min; a higher value indicates a higher level ofcardiorespiratory fitness.Your maximal aerobic capacity or oxygen uptakeis the best indicator of how much work youcan sustain without fatigue.Typical VO 2max values range from 30 ml (of oxygen)/kg/min for an unfit person upto 80 ml/kg/min for an exceptionally fit, endurance athlete. If the unfit and highly fitpersons both weighed 70 kg (155 lb) then their respective absolute maximal aerobiccapacities would be 2.1 liters (of oxygen)/min and 5.6 liters (of oxygen)/min.Using 1 liter of oxygen/min is equivalentto expending 5 kcal/minAs such, the unfit person can only work at a rate of up to 10 kcal/min (2.1 L x 5)whereas the highly fit could work at up to 25 kcal/min (5.6 L x 5 kcal) if needed. If aspecific task required 2 L/min, then this would amount to 10 kcal/min of energy. Restingenergy expenditure requires less than one kcal/min, or about 0.200 to 0.250 L (of oxygen)/min. In order to account for different body sizes, resting energy expenditure for anindividual is usually defined as:3.5 ml of oxygen/kg body weight/minute.Thus, for a 70 kg (155 lb) SEAL, resting energy expenditure would be approximately 245ml/min or 0.245 L/min (3.5 x 70). This is equivalent to expending around 1 to 1.25 kcal/min.The Navy SEAL Physical Fitness Guide 33