This morning I had a recovery paced 13km on the schedule, but when I woke up for that, my legs were feeling thrashed- 11hrs recovery after a tough run like I did yesterday just wasn't enough. That got me thinking- in order to really optimize training, I need to give though to when I do my runs.
Getting out for a pre-dawn run every day works, since I generally have a full day's recovery between runs, but when I start to mix up my schedule, I can end up with much less recovery time than necessary. It wouldn't have been as big a deal on a run like I had on the schedule for today where it was just slow and easy, but if I had a speed session scheduled, it would have been a disastrous training session.
When training for marathons, we often think of the training just as the running, but it's the recovery too, and not just the rest days. The amount of hours you get between runs is quite important.
Sometimes (often) life gets in the way and you've got to do what you've got to do, but if you have the luxury of planning the times of your runs, give some thought to hours of recovery- try to not schedule a tough morning run after a tough run the evening before (unless you're specifically working on running on tired legs). Those few extra hours you can give yourself to recover can make a big difference in your performance in your training session.