Dan, I've tried and tried - heavy barbell, heavy dumbbell, alternating light and heavy, seated, standing, leg bent slightly, off a step, toes out and in. I can get a burn going if I do upwards of 75 reps with 15 or 20 lbs on one leg, but a 'burn' and 'failure' aren't quite the same, right? (lactic acid build up vs. failure)

I'm not complaining too loudly - I mean, I do have defined calves so something is working. I think it's just that while I spent years and years doing all that cardio (exclusively) it was cycling/spinning, jogging and on a stepper and/or ski machine.

I did once get them 'hurting' while doing hamstring curls, but that was before I 'learned' to point my toes to isolate the hammies. Maybe I could do a few sets specifically for calves ?

Nat