V6 wrote:
I did 16x400 in 73 working down to 68 with equal rest (rest is the same as your last split)
I've also done 24x200 in 32-27 with 1 minute.
I've 6x1600 averaging 5:35
8x800 in 2:35
Does this indicate anything faster than 4:40 for the 1600?
The first two workouts on that list don't seem to square with the last two. The split times of the shorter sessions are indicative of a higher level of fitness than the two longer sessions would indicate.
I've run under 8:40 for 3k and under 15 for 5k in the past two months, and last week, I ran a 1600 in 4:45, 5 minutes rest then 12x400 between 67-79 with 90 seconds rest. Two weeks before that, I ran a workout of 1600 in 4:48, 5 minutes rest, then 16x200 with alternating recoveries of 60, 75, and 90 seconds. The 200s started just over 33 and finished just over 31. I thought I was moving pretty well in those two workouts. Your 400 repeat session would be a good workout for me, and I don't know that I could complete your 200 repeat workout at those splits with that little recovery.
I'd say you need to boost your mileage in the base and middle phases of your program, and do some continuous 20-25 minute tempo runs. You obviously have the speed and are somewhat lacking in the endurance, but the potential is there to run under 4:30 much less 4:40.