8-10 x 500m @ YOU DECIDE – either 10k pace? or 1/2 at 10k pace 1/2 @ a little faster pace  BUT JUST KNOW, YOUR RECOVERY IS THE JOG STRAIGHT ACROSS THE END ZONE – BACK TO THE START. 

If you do all 10, that’s 5000m and it may be too hot for that. So don’t beat yourself up too much. 8 is sufficient.