More challenging intervals fill the three workouts on Disc Three&44; designed to take advantage of the gains you&8217;ve made in aerobic performance & now include intervals that target & increase your sustainable power at lactate threshold. Nothing makes you faster on a bike then increasing your overall power. Carmichael Training Systems Progressive Power DVD&8217;s are designed to do just that &8211; use them independently&44; or combine all 5 DVD&8217;s&44; to get 16 power workouts that studies show can increase your overall sustainable power by 12% (Klika&44; et al.&44; 2007). &8226; Each DVD contains three 1-hr workouts. &8226; Also available as a complete 5 Disc DVD pack