Energy Expenditure During Rest,Walking, Running, and Swimming Chapter 9 &10

Gross & Net Energy Expenditure Gross expenditure is the total for the entire body mass Net is the Gross minus the RMR Net = Gross - RMR

Factors Affecting Aerobic Performance VO 2 max Anaerobic Threshold Movement Economy –Muscle Fiber Types –Mechanical Efficiency

Stride Length & Frequency and Speed Increasing Running Speed –Increase in stride length –Increase in stride frequency –Increase in both length and frequency Running speed increased mainly by lengthening the stride. Only at faster speeds does stride frequency become important

Running Economy in Kids Kids require 20-30% more energy to run at same speed compared to adults. Decreased economy due to: –Increased surface area to mass ratio –Shorter stride lengths –Poor running mechanics

Energy Cost of Swimming High ability swimmers have low energy cost of swimming Water temp effects energy cost Women have 30% lower energy cost