Got some work to do

I managed an 8k run this morning so I am improving. My problem is my ankles. They are weak and when I get to between 7-8k they start to tire and go over (this has improved they were doing it much earlier).
I mentioned it to my friend when we went to see their new house this afternoon and he has given me this wobble board and some elastic bands 
The wobble board is harder to stand on than it looks.
I just have to do it for as long as I can and build it up.
I have some work ahead of me.