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

Watts, as stated above, are units used to quantify the rate of doing work, or work/time. Most new exercise equipment express work rate in terms of watts, although many useMETS instead of or as well as watts. Table 3-13 presents the relationship between variousterms denoting exercise intensity. These can be used to monitor exercise intensity.Table 3-13. Workload Conversion SheetWattsOxygenUptake(L/min)Work RateEnergyOutput(kcal/hr)METS50 0.9 Easy 270 4.0100 1.5 Fairly Easy 450 6.7150 2.1 Moderate 630 9.3200 2.8 Moderately Hard 840 12.4250 3.5 Very Hard 1050 15.5300 4.2 Very, Very Hard 1260 18.7SummaryNo doubt new modes of exercise will be appearing in the future. What you chose touse will depend on many factors. The important issue is whether you are able to achieve thedesired work rate and conditioning level. A recent study of indoor exercise machinesexamined energy expenditure at given ratings of perceived exertion. They compared atreadmill, a rowing ergometer, a combination cycle/arm ergometer, a cycle ergometer, astairstepper and a skiing machine. Surprisingly they found that rates of energy expenditurevaried by as much as 261 kcal/hour for the exercise machines when subjects exercised atself-selected work rates corresponding to fairly light, somewhat hard, and hard. Thetreadmill came out with the greatest energy expenditures, followed by the rowing andstairstepping ergometers; the cycle and combination cycle/arm ergometers came out withthe lowest values. If exercise intensity is established by perceived effort, treadmill running/walking will result in greater energy expenditure and a stronger cardiorespiratory trainingstimulus for a given duration of exercise as compared to other modalities.The Navy SEAL Physical Fitness Guide 51