40 minutes steady state

4′, 3′, 2′ 1′ @ 18, 20, 22, 24
at the beginning of each rate change take a 10 at full pressure at a 30 rate and then immedietely go down to the steady state rate.

This workout raises the heart rate and then allows it to come down to the 60%-70% effort. Over time it will take a toll. Be sure to breathe and stay poised throughout.