Hi Mitchel, dang re: calf flaring up
focus on little steps when going for the 5k time .. 4:15 per k = 21:15
your last session was the following:
1st km: 4:16 min/km
6th km: 4:06 min/km
if you take this session add all the 1k times together divide by 6 x 5 ..
take that time and add 20 to 25 seconds
and that is more or less what your current 5k time is
so better to aim for that time for the future
and in answer to the earlier question
if no race then 4 to 8k time-trial according to your choice
better .. 4k . 6k or 8k
hope this helps
ps.. what you have in mind to fix the calf ??