The need for even more speed endurance

Wednesday was primarily a rest day - just a light run with the Mountbatten girls at 7.30am with the temperature at minus 3 degrees. Apparently it was my fault that everyone turned up in T-shirts and shorts, except for me who had four layers on.
Tonight I thought cranking out another speed session would be a good idea. It wasn't.

Fairly cold, but little wind on the track.
3x300m with 5 mins recovery
44,44,48 First 2 runs not too bad (although from Tuesday's times I should have been doing low 40s) but by the end of the second I was really feeling it. The third was just a slog. Desperately hanging on in the last 100m.
I'll keep at this. Try another of these sessions on Saturday and then taper off next week.
Maybe a hill session tomorrow, but easing off the speed a bit.