After my 8-mile training run, I wanted to figure out what ratio of running/walking I should plan on for the half in November. I did today's run at 5 min run/1 min walk intervals, which seemed to work out fairly well--I was tired without being completely spent, and I was able to maintain the intervals for the entire distance, even running on the uphills! I would love to be able to cut 30 minutes off my previous finishing time of 3:40 (I would also love not to have a meltdown at mile 11), which requires an average pace of 14:30/mile. So, using my average pacing for today's intervals, I devised the following equation:
13.5R + 17.5W = 14.5 (R+W)
where R is the distance spent running at an average pace of 13:30/mile, and W is the distance walking at an average pace of 17:30/mile. The second equation is:
R + W = 13.1
to indicate the total distance of the race.
Solution: R = 9.825, W = 3.275
which means that to finish the half marathon in 3:10, I need to run about 9.8 miles and walk 3.3. Multiplied by my average paces, this would put my intervals at 5 min running/2 min walking.
Nerdiest blog post ever? Extremely likely. But I do enjoy knowing that my goal time is within reach if I can continue to maintain my current pacing, AND even allows for an additional minute of walking per interval (those 60 seconds sure do fly by)!