One mistake I've made numerous times since I started running is upping mileage and/or making too many changes in terrain/mileage too fast. This year, I've been careful to build a base before increasing mileage and I am trying to slowly increase my total weekly mileage. For a few months, I allowed my work days to be so long and draining that I ran few miles during the week and the crammed in the majority of my miles on the weekend; thought that was not optimal, it that allowed me to get used to running longer distances on legs tired from running the day before.
I use dailymile for tracking my runs and looking at my weekly totals has been useful in making sure I am not doing too much, too soon. March, April, and May, I focused on building a mileage base and increasing that to 20 miles per week; at the same time, I made my physical therapy exercises a key component of each day and gradually grew accustomed to running in different shoes. Before my last PT bout, I had been told I needed orthotics and shoes with some pronation control; in talking with more running-focused clinicians, I learned that those two items actually make my running gait worse and that I should be in neutral shoes with a minimal heel-toe drop.
Now that I have established a solid running base, I am trying to keep my weekly mileage increase close to 10% per week and am including cut back weeks. Two weeks ago, I hit 35 miles per week and did a cut back week last week. This week, I am targeting 39-40 miles and will use this week as a major test for whether a winter road marathon is feasible. I am also incorporating a little swimming into each week knowing that cross-training is important and I should take advantage of the warm temps and apartment pool.
Twelve months ago I could not walk without my hip buckling and each mile is now more cherished than before. I was thrilled to spend this Labor Day running!