This ride is designed as prep for a 70.3 race. All Muscular Endurance workouts are intended to build your aerobic zone power output and improve your endurance at that power.
Ride two hours on a flat to rolling course. Warm up 30 minutes
Main Set: Ride 5×12 minutes at Zone 3 in aero position (three-minute recovery spins)
Transition to a 30-minute run in Zone 3.
Note: Beginners can shorten intervals to 5×6 minutes in Zone 3.