Pretest-MAF running

Reading a new endurance book, The Big Book of Endurance Training and Racing.  

I love numbers and new training plans, so this got me excited.  I also am curious to why I train at such a fast pace, but my race times don't correlate.  Something's going on.  Either I just don't race well, or I'm lacking aerobic fitness, as this book leads you to believe.

The book tells you to train in your aerobic MAF zone (which for me is 138-148 beats per minute).  No anaerobic training allowed during your aerobic building period.  This is hard for me because I enjoy fast track workouts & HIIT intervals, tempo runs...basically anything that leaves you exhausted & worked.  

Anyway, I decided to give myself a little pretest today, since I had an easy 8 on the schedule.  I wore my heart rate monitor and decided to warm up a mile, try to run in my target heart rate for 6, and then cool down a mile.  Here are my pretest numbers:

Mile 1 (warmup) 8:51 pace, 129 HR

Mile 2 8:24 pace, 143 HR

Mile 3 8:15 pace, 142 HR

Mile 4 8:22 pace, 143 HR

Mile 5 8:29 pace, 144 HR

Mile 6 8:32 pace, 143 HR

Mile 7 8:24 pace, 144 HR

Mile 8 (cooldown) 9:08 pace, 138 HR

Observations:  This didn't seem as easy-feeling as everyone says in the book.  In the book, you hear COUNTLESS stories about how running in this heart rate feels turtle slow.  It didn't feel slow to me, just felt like my normal running pace.  Hmmmm.  

I'll continue shooting for this heart rate in my running.  Currently, I'm scheduled for around 65 miles per week, building to around 80 towards end of summer for my fall marathon.  

I think I'll do another test in 4 weeks to see what results I get.  My prediction is, I'm not going to see much increase in my speed with the same heart rates.  I have a feeling I have a solid aerobic base and I just suck at racing.  We'll see!!!