M4 (Criss-Cross Threshold)

I really like these training rides. For some reason they force you to work harder than you think you are capable of. These training rides are known as lactate tolerance intervals. The duration is typically 20-40 minutes with interval duration of 3-5 minutes. You ride 3-5 minute slightly above your lactate threshold (LT) and then 3-5 minutes slightly below LT. During the time spent above your LT you are slowely filling your muscles with lactic acid you then switch to an intensity slightly below LT and force your muscles to work hard despite the fact they are filled with lactic acid. With the initial warm up of 20 minutes and 32 minutes of intervals that leaves a little over 1 hour of time to finish the workout at an E2 intensity.

Summary
Duration: 2:00:00
Intervals: 4
Interval Duration: 4 minutes
Rest Duration: 4 minutes

Detailed
0:00:00 - 0:20:00: Warm-up
0:20:00 - 0:24:00: Interval 1: 21 mph
0:24:00 - 0:28:00: LT Tolerance1: 20 mph
0:28:00 - 0:32:00: Interval 2: 21 mph
0:32:00 - 0:36:00: LT Tolerance 2: 20 mph
0:36:00 - 0:40:00: Interval 3: 21 mph
0:40:00 - 0:44:00: LT Tolerance 3: 20 mph
0:44:00 - 0:48:00: Interval 4: 21 mph0:
0:48:00 - 0:52:00: LT Tolerance 4: 20 mph
0:52:00 - 0:56:00: Recovery: 18 mph
0:56:00 - 2:00:00: E2: 18.5 mph