I came across The stillman formula a while back, which I decided to follow. Did a check and found my normal ideal weight should be 148 Lbs. As I run long distance, should be aiming at 20% below normal range. So my normal weight is 10 St 8lbs, minus 20%. Giving a running weight for my 6ft 3 inch frame is 8 stone, 4 lbs.

This is what I've acheived, and it does work, finding running conistant and quick recovery.

Anybody aiming for this formula? Google search and explains all.