In order of importance I'd suggest (once the acute phase is over when you can't do much except rest):
deep tissue massage from sports injury therapist or similar
carrying on running but at very light intensity on smooth level surfaces - but stop if acute, sharp pain
ice after massages/runs, otherwise keep tendon area warm
stretching, gently at first, e.g. keep ankle flexed by keeping toes up resting on something when sitting, graduating to heel drops off a stair (including eccentric). Be sure to make full heel placement on the ground when walking or descending stairs
elevation - sleep with your foot on top of a couple of pillows
be patient (perhaps should be at top of list)
Things to avoid:
high intensity running /exercise - no racket sports, downhill running
sitting for long periods - keep moving
standing on tiptoe
I had achilles tendonitis for 15 months, managed to continue with most of my events during that period (at a slow speed), and now it is as if I never had it. It has never recurred.
Talking with the organisers (to apologise that I gave then safety concerns) it seems the guy who was so late back wasn't following me at all but got lost going to the NE of Waun Rydd somewhere, so well away from me.
This begs the question - what was the light that was following me?? This is now the third time during night running that I have been troubled with lights.
After a major clean up and shower, I managed to get my head down in the tent, but only for half an hour. By 0600 lots of people were getting up, breaking camp, and making noisy departures. I went over and had breakfast in the YH instead.
I thoroughly recommend this event. I won't be doing any extensions again and I would be happy to run around with brer or anyone else, assuming I can keep up.
The normal route is about 55 miles, and my version, surprisingly, was still only 59 miles.