Notes
hip flexor tight as all hell but run was good overall...HR avg was 148 which I thought was a little high for the tempo I was running...big day of stretching ahead.
Training Plan Entry
Long
18 mi
16-18 miles.
If it's an option, try to see how much vertical you can run for this.
All of this is relaxed for volume and consider today and tomorrow one workout. You want them both to be solid which means you go easy today and then if you feel awesome tomorrow you can push. This no different than the strategy you use in an ultra.
Max HR for this would be 155 and place a focus on hydration and nutrition intake early in the run. ASAP after try to take in ~50-60g of CHO.