I have been doing HIIT Training this summer about 4-5 days a week. I have noticied it is difficult to get a hard core calf day in during this type of training. A few days after a heavy calf day my calves are still a little sore but the difficulty is when running, the front of my shins start to ache so bad it is hard to continue. Through the course of the summer I have laid-off calves for a week at a time to be certian I didn;t have "shin splints", and the week that I have laid off my legs feel fine. I completed an intense day of HIIT yesterday, doing 10 40 yard sprints, 4 100 yard sprints, 2 400 yard sprints and 6 intervals on the stairs, in less than 25 minutes and my claves did not hurt and I have not done calves for about 5 days and even that day was pretty moderate.
I stretch the front and back of the lower leg before, during and after running and it doesn't seem to matter if I am running preceding a heavy calf day.

Has anyone else experienced this?

I think in a way this is a shin splint. I suffered from these as a teenager. Basically the doc told me my calves were so tight that when i ran it made the muscle want to pull away from the bone. So when youve had a heavy calf day the muscle is tore down and usually tight with a bit of water...i know mine are...and you trying to run with this is basically creating a shin splint because the calf id more engorged than usual. I think its a matter of stretching everyday...or switching your cardio away from running...i know i wouldnt quit training my calves so i could run...but thats just me.

JT--