I've found that the most dangerous time for me with respect to running injury is while transitioning from a rest phase to high mileage training. Resting doesn't entail injury, and when I'm running high mileage I rarely get injured, but in the ramp transition I have to be careful and watch for signs of incipient muscle strains, knee soreness, tendonitis etc. I've come to think of this transition as the "crossing the surf-zone": Once I get the milage up above 50 miles/week I'm in "deep water" so to speak and I don't get tossed on my ass by the breakers. The body seems to have accelerated healing and strength which keeps injury at bay.
My mileage log since the start of the year shows this. I've learned to back off when problems flair up and I've gotten in a few weeks in the 4-50 miles per week range... with occasional rest days or a pair of rest days thrown in when hot spots develop. I am just about out of the surf zone now, but not quite. The latest issue has been a flair up of my achilles of the left leg, which last bothered me after I got off crutches after my accident in 2014. Lat week I ran in to my Pal Joe on the trail on my lunchtime run; we added a few miles and ran a bit faster than I've been used to in my "surf-zone" training ramp. Toward the end of the run the achilles let me know it was unhappy. That evening it was sore and so I took a couple days off. It was still iffy on Friday so I walked on Saturday; this morning I elected to do a long walk up/ run down workout on the Mt. Wilson Toll Road to get some mileage in without overly stressing the tendon. It seems to have worked, the achilles has felt fine all day since.
It does help to have various tools for the job at hand. For todays run I donned a pair of Hokas leftover from my 2015 season. "I don't always heel strike, but when I do, I wear Hoka's".