Yes, that has been ok for me. I try to not be too foolish, but I find that the "hard" days can be hard and the "easy" days VERY easy. So I ran only 2.5 miles yesterday, and won't go to the track until Thursday, for my only other hard weekly effort. Since I have run for over 36 years now, I find that it's hard to get over 40 miles per week (actually, I don't remember the last time I have done that, I'd have to scan my last couple of years of running logs). Plus, at age 62, I can do a large, hard, or long run, but my give myself quite a bit of recovery time. I didn't feel too tired till the last mile, so I think my body's adapting well. I did do a 30 minute bike ride indoors, too, so my total run time for Sunday would be about 33% of my total workout time of the week. I don't suggest this for all, but it works for me, just as I have also found that increasing the long runs can be of 10-20% for me, not the 10% rule. We are an experiment of one, and I enjoy my experiment.
Since I spend a fair amount of work time on my feet, plus I enjoy my free time doing other things (guitar, state road racing record keeping, housework, etc.) it is a balancing game of my time and energy. Two months from today is my marathon, I hope to complete and run well in. I should note, too, that I have not run a marathon in about six years or so, and Sunday was my longest run in at least one year, so am exploring the "unknown" cautiously, but willingly. If I feel awful this Sunday, I won't try 16, I know I can be flexible.
The last 6 years have been so dedicated to work that my racing was primarily focused on 5 km's. With the tragedy of Boston, I was moved to try to qualify for it once again, and thus my current goal. Thanks for asking!