Phew, after the dreaded 20 minute run of W5, I had to take two days before the first run of W6 but did it tonight and it was actually fine! So was the 20 minute run of three days ago I mean, it was tough and my legs were really really tired AND the next day my left thigh really hurt so I left an extra day in between, but overall... GREAT!! I am totally amazed that after starting five weeks ago my body can now do this! Yes, I'm shattered afterwards etc etc but that's a good kind of shattered and I love it. Also, lost about 10 pounds of weight since I started, YEAHHHHH!!!!!!
PS Took the advice about stretching after the run and it does help greatly, thank you all!