Warm up: (10 mins total) 5 mins easy spin, gradually increase effort 3 mins as 30s fast effort, 30s easy recovery 2 mins very easy spin - - - Main set: (30 mins total) 3x (1,2,3,2,1) min HARD effort (top Z4 FTP effort) off 1 minute easy spin recovery. Efforts in aero position if possible. - - 3 mins easy spin recovery between sets - - - - Power meter users: HARD efforts at 100% FTP for each interval. Use power as your key metric, even if you are also using a heart rate monitor. - - - Heart rate only users: Complete session with HARD efforts in HR zone 4. - - - Easy spin cool down for the rest of the session.