This is frustrating, because I've been feeling in the best shape I've been in all year. In addition to extending my long run further, I've done some road running and found my shins are holding up well to downhills. However, I've had a day each of the last couple weeks where my right Achilles area felt tired. I backed off a little, but after my last longer run on roads, my Achilles flared up, and was sensitive the next day just walking around.
I'm skipping my long run this weekend and taking a zero day tomorrow, in trail hiking parlance. Not just a zero day, but a zero weekend. It looks like I'm guilty of the old "too much, too fast, too soon" trap once again. This time I think it was the "too much" category.
This is a new sort of running injury for me. I'd been prey to shin splints/tendonitis before, but have managed to keep those at bay this year with gradual mileage increases, running many of my miles on sandy trails, and using both sides of the road when running on roads (recommended only on quiet roads and without listening to music). We'll see how it feels next week.