M4 (Criss-Cross Threshold)

Breakthrough Workout:

I really wanted to hit this workout hard. Because I completed my last E2 (endurance) ride early Wednesday morning I was well rested (36 hours) and the legs felt good. The last time I performed the M4 workout my work intervals were at around 20.9 mph and the rest intervals were at 19.9 mph. The goal for this workout would be to hold over 21 mph and 20 mph respectively. During the warm-up my legs felt really good and my heart rate remained fairly low for the effort. During the intervals I easily hit my goals and they were easier than last time. I had enough energy in the legs that I decided to finish the workout with a one hour duration at slightly below my lactic threshold (19.5 mph, 250 watts). I found it fairly easy to hold that pace for then next 45 minutes. The last 15 minutes, however, I struggled to hold that pace and it slipped to around 19 mph at the end. In all a very good workout; I can feel it in the legs going up and down the stairs.

Summary
Duration: 2:00:00
Intervals: 5
Interval Duration: 4 minutes
Rest Duration: 4 minutes

Detailed
0:00:00 - 0:10:00: Warm-up
0:10:00 - 0:20:00: E2
0:20:00 - 0:24:00: Lead in Interval
0:24:00 - 0:28:00: Interval 1: 21 mph
0:28:00 - 0:32:00: LT Tolerance1: 20 mph
0:32:00 - 0:36:00: Interval 2: 21 mph
0:36:00 - 0:40:00: LT Tolerance 2: 20 mph
0:40:00 - 0:44:00: Interval 3: 21 mph
0:44:00 - 0:48:00: LT Tolerance 3: 20 mph
0:48:00 - 0:52:00: Interval 4: 21 mph0:
0:52:00 - 0:56:00: LT Tolerance 4: 20 mph
0:56:00 - 1:00:00: Interval 5: 21 mph
1:00:00 - 2:00:00: Threshold: 19.5 mph