One minute on / one minute off strength endurance work today. The power is Z3+ so sub-threshold, but the work will add up over the course of the session. WARM UP: 10 min easy Z1 spin. Then hit five min as: 5x (30s high power / 30s easy). 3 min easy spin and into the main. MAIN: TWO rounds: 8 x (1 min @ Z3 power, 50-60 RPM / 1 min easy spin, 90-100 RPM) 5 min easy spin between rounds. POST: 4 x (1 min @ Z4 power, 50-60 RPM / 1 min easy spin, 90-100 RPM) COOL DOWN: 5-10 min super easy spin and done.