Hi Randy - See my other posts on this issue. I started my own discussion on aquablation recovery a few weeks ago, and I have posted several times on Ihsan's thread. I had aquablation almost three months ago. I am very pleased with the results. My urinary function is now perfect, and my sexual function is the same as it was prior to the procedure, which was also perfect. So I am a big fan of the aquablation procedure.
But I must say that the medical field drastically underestimates the severity of the recovery from this procedure. The standard line is the information you quoted, about returning to normal activity after 3-4 weeks. That is all the information that the medical establishment seems to make available. In my experience, that information is not inaccurate, just incomplete.
What they don't tell you is that the recovery for the first three weeks or so is absolutely miserable, at least it was for me. For much of that time I was experiencing sharp pain when urinating, urinary incontinence, bloody urine, pain with erections (the only erections were involuntary night time and morning erections), swollen and sore testicles, constipation, etc. If you are concerned about training, you need to block off at least the first 3-4 weeks after the procedure, when you will not be able to work out at all. There is no way you could train for any kind of athletic competition during those first 3-4 weeks. It was a challenge for me to walk from the couch to the bathroom. Then you will need to deal with getting back into shape after about a month of virtually no exercise at all.
The one thing I need to mention, though, is that when you start to feel better, it happens very suddenly. At some point during the fourth week, I suddenly realized that I felt like myself again. I had regained full urinary control, my energy level returned, and I was sleeping much better, only waking up about once per night to urinate. So, while the first period after the procedure was terrible, when I started to get better, I got better very quickly. By the end of week 4, I felt totally normal.
I am not the athlete you are, but I do work out regularly, as a competitive swimmer. I asked my urologist if it was OK to start swimming again, when I saw him for a checkup about 4 weeks after the procedure. He said to go ahead if I felt up to it, but to be careful not to overdo it. By the 4th week I dipped my toe back in the pool, doing about half my usual workout for the first week back, then full workouts after that. In the context of training for marathons, I'm not sure what that would mean. My guess is that your training schedule will be seriously interrupted, if not completely cancelled, for about 5-6 weeks.
As for sex, I was told to abstain for six weeks. That was as miserable as it sounds. Others on this board have been told to resume sex after two weeks. I found that I wasn't quite ready for sex at six weeks, but after seven weeks or so I was fine. It's the same now as it was before. See my detailed response to Blair on this issue, which I just posted yesterday and today.
Good luck with whatever you decide to do. My guess is that if you were able to get the procedure scheduled by the beginning of April, you could be back to running by the end of May. But you would have missed the training you are probably doing for all of April and most of May. If that timing works, you'll be glad you got it done.