Jog over the woods

Friday today and I haven't been running since Sunday.
Went for a quick run with the dog.

3.1m
30mins
152 avg bpm
174 max bpm

Legs felt heavy and it was pretty hard work.
Reading half marathon on Sunday but my under 2hrs doesn't look likely if I'm this sluggish.
I'll run at my set pace for 5 or 6 miles then I'll decide wether its on or not, then I can go for it or ease of and enjoy the run, although I can't imagine Reading being that scenic.