Back on Track 18x200m and 2x300m

I decided it was time for some high volume pace work. I ended up doing 18x200m alternating between 30 and 31 seconds. I finished with 2x300m @ 45 seconds, 42 seconds. I ran in my road racing flats. I had a rabbit for the last interval that helped me run faster than I thought was realistic for me. I have mainly been doing base training and I believe that this translates into speed endurance. I never felt like I was going into oxygen debt when I did this workout. My goal is to feel completely relaxed doing 60 seconds for 400m for 8 t0 10 intervals with 90 seconds rest. Lately I have been getting good sleep and keeping a healthy diet.