Being a sprinter again

Four days ago I began HiiT. For those who don't know what that means, or read my blog regularly, it's a method of training that stretches the cardio beyond the limits of distance running. Essentially, I work 95% (or perhaps 70-80%) or so for 4 minutes, and then rest for a minute. The purpose of the rest is two-fold:

a) To let the heart rate, and lactic acid levels, drop to manageable proportions so that you can cane the next set.
b) To get used to feeling of my heart being stressed at beating at 180-190bpm.

Three days ago I did my first HiiT session since I started my marathon training. I felt as if I was going to be sick. Today, though, even though I have head cold, I felt it was manageable.

There is the small matter of the ongoing niggles from the marathon. The front of my kneecaps is still slightly sore. And my right foot feel strained (although no longer torn.) I wonder if the intensity of the 10k will exacerbate these and actually injure me. Or whether my body will rise up to this challenge and grow stronger.

Right now, though, I am chewing on paracetamol and throat sweets - my nose and throat itch like raw gratings.