3x9' progressive climbing strength. Its great for off-season/base period as you highly address your muscles without producing high lactate values! This is a tremendous advantage! Only do this workout if your joints/knees are fine and if you fit on your bike correctly. The negative effects of a wrong framesize or wrong bikefit are amplified by this workout. Do this workout once a week, best Saturdays before your long Sunday base ride on Zwift!