10 miler with stiff legs

I've been suffering a bit with stiff heels in the morning after a run and I've been worried that its Achilles problems.  On my run this evening I tried out some heel supports in my trainers, which are designed to absorb the impact.  The first 2 miles were tough as my heels, glutes, calves and hamstrings were all stiff (good advert for running aren't I?) but this is often the case after a tough session the night before (last night's session was Kenyan Hills).  The run always gets easier though so I know that I can keep on going at a slow pace, its all about listening to my body and not pushing too hard.  When my legs feel looser I can pick up the pace slightly but nothing too fast on a long run, I don't want to feel too tired for my quality sessions later in the week.  Ten miles is a nice distance, long enough to be a good workout but not too long that you have to worry about taking gels, jelly beans etc.  As I had been running up and down hills for 25 minutes last night I was conscious that I didn't want to be running up too many hills tonight and managed to avoid anything too strenuous, finishing the run strongly and hopefully able to run a decent parkrun in the morning, will let you know....