Run like the old days only a lot slower

Today was scheduled as a rest day but it was so nice this morning (Sunny and low 60's with a nice breeze) that I decided to get a run in.   It was as much to clear my head as it was to increase my cardio.  After 6 years of just doing crossfit my running capacity has really gone downhill.   Not surprising since I am considerably heavier (180 vs 168) and a bit stronger as well.  In my mind the mass isnt very useful if I cant move it or I get tired quicker.  Im not sure if it is just getting older or what.    Did the one of the old standby routes to Nobles and back.   Way harder than it should have been for the pace.  In fact the HR was at 171 on the last leg. 

10x15 of Double Unders - Not good at all.

I need to get more runs in without a doubt to increase my conditioning.