Hi Lirish by all means train but to be honest I did very little due to work and family commitments (four deaths in the family last year). My best week not counting events was 50miles . I averaged less than 20miles per week.
Mountain Marathons were my best training: Hard hill running day one with full pack then overnight camping and running the second day. Added to this the navigation at speed and you have the perfect Spine training weekend.
The first few spine days actually re train your body to run without sleep and up your food consumption to disgusting levels. (6 full meals a day +all the shock blocks , energy bars and fluid you can wolf down!
Once above about 180 miles your legs are not tired at all by your sustainable pace. At 180 miles I accelerated to a pace I have never achieved before on an ultra (I could not navigate fast enough for my pace) I became an eating /running machine. I flew into one Pub to re fuel ,ordered a pint of pepsi then shamelessly eat the left overs on all the plates in the pub cos I could not wait for food.
This race is about constantly managing yourself and listening to your body.