Hi everyboby any advice would be appreciated.

Im trying to get ready for the 3 peaks and cant decide which way to go about it. Is it better to spend time on your feet with lots of miles (is there a minium you need to do) or start off shorter and faster and build the time spent on your feet. Last year I managed 4hrs 22mins at the peaks on this type of training but I realised it was not enough.
At the moment I only do 3 sessions a week which are.

5-7 miles on the road 7min-7.30min/mile this will be built up to 8-9miles
8 miles trail/fell ave 1500ft climbing hard but doable. This will be built up to 10-12 miles
10-13 miles on fell 2000ft/3000ft as hard as I can go. I will build this longer run up to about 19miles with 5000ft a couple of weeks before 3peaks.

Last year I managed 4hrs 22mins at the peaks on this type of training but I realised it was not enough.

I know I need another session but dont know wheather to run or bike and when to introduce it.

Thanks in advance for any replies.