We have complicated the hell out of cycling. In my opinion running should be simple and is best kept that way.
If you really must quantify things your best bet might be to find a repeatable course/loop and race it as hard as you can now and again, and compare times. Do some races if you can, because people always find another few % when chasing after other people. If you can do a proper 5k or 10k at full race pace somewhere flat-ish then you can compare these times on the mcmillan tables and derive training paces from there, but it only really works over similar terrain (ie 5k flat pace doesn't give you a very good pace to use training on a hilly course).
http://runners-resource.com/...-running-calculator/
Jack Daniels VDOT pacing also an option as pointed out.
Or you could try and use that Karvonen heart rate bollocks, but you'll take all the fun out of it.
If you really must quantify things your best bet might be to find a repeatable course/loop and race it as hard as you can now and again, and compare times. Do some races if you can, because people always find another few % when chasing after other people. If you can do a proper 5k or 10k at full race pace somewhere flat-ish then you can compare these times on the mcmillan tables and derive training paces from there, but it only really works over similar terrain (ie 5k flat pace doesn't give you a very good pace to use training on a hilly course).
http://runners-resource.com/...-running-calculator/
Jack Daniels VDOT pacing also an option as pointed out.
Or you could try and use that Karvonen heart rate bollocks, but you'll take all the fun out of it.