Canova marathon Fundamental phase help: how often to do each workout?

basically, should the workouts in Fundamental phase be massive efforts - thus only 2-3 week would be possible - or are they meant to be restrained to get in as many (4-5 a week) as possible?

The Canova stuff isn't a training formula, it's a collection of training principles. How to correctly apply them depends on your training background and ability level.

Long story short if you can answer this for yourself you don't know enough to be using this training.

that's not really true, canova himself has given out percentages in the past, as below:

"10% of mileage at a very slow speed (including warm-up and cool-down), 20% at speed between 65% and 75% of MP, 20% at a speed between 75% and 85%, 25% at a speed about 85% and 95%, 20% at a SPECIFIC speed (95%-105%) and 5% at speed faster than 105% of MP."

however it's still unclear if this should be concentrated in 2-3 workouts a week or if there should be one of the 6 types of workouts each day with one unstructured day.

Great question. Canova sometimes posts in here….