Can I get the same or better fitness for 5k Xc with 6-7 days of short but fast and hard training rather than grinding out 60 -70 mpw?
Can I get the same or better fitness for 5k Xc with 6-7 days of short but fast and hard training rather than grinding out 60 -70 mpw?
5k/cross country running is all about aerobic strength. Ie more mileage the better to a point. There is always a point of diminishing returns.
You're much more likely to overtrain running too hard. You won't overtrain by running too much mileage at an easy pace, especially when you have many months to adapt to it.
You are asking two different questions.
5K is aerobic. Err on the side of too much aerobic training rather than not enough. Don't over-sharpen your pencil.