Thank you, Jon!
It´s great how many fast runners are logged in here! Amazing your running accomplishments, you can be very proud!
In February, I planned exactly what you describe as general rule of thumb. What I´m not sure about is the length of my long runs, since I injured doing long marathonpace-runs (15, 20, 25k each 3 weeks apart) for my last marathon. I didn´t have enough mileage weekly to do that... Here I got some good advice from jtshad I am very thankful for! He suggested a linear buildup for my long runs (like 15, 16, 17, 18, 19, 20 miles or so). These days I read a lot about George Malley (malmo) who says:
What my point about the long runs is that they are way overrated, are disproportionately done with respect to the overall mileage and training goals, and should not be done at the expense of the other aspects of your training.
He even says that 25% of weekly mileage is too much...I think running long runs of 20 miles definitly have a mental value, but I´m not sure if just doing more mileage and spread it over a whole week would be a better option (to stay healthy). Another idea of mine is to just do 1 or 2 very easy 20 milers just to build confidence and feeling for the distance. Others long runs would be in the 10-13 miles range. Any suggestions?
Second question about your rule of thumb: where do you go from there? Skip rest day and doing a short easy run? Doubles or longer single runs? A combination of both?
Much appreciate any advice,
Martin