After I completed the MHFS 10k last Sunday, I felt a niggle in my right thigh and groin, but thought nothing of it, and it went away. On Wednesday I done my sprint training, and it came back, with more pain. The Physio I use told me today, I have a grade 1-2 rectus femoris tear, which I should rest for 7-10, (possibly 20) days. Is there anything I can do in the mean time to keep my fitness up, as I was meant to start my 12 week half marathon program on Monday?