Just thought I'd lay down my thinking about how to tackle the Jungfrau. Having done endurance stuff since I was a kid I have no concerns about the distance but there is a risk of sheer exhaustion (bonk, cramp, dehydration) if I don't tackle the second half properly.
Unlike most hill races the Jungfrau is literally a race of two halves. The first is like a bog standard half marathon with only 300+ m of ascent. In the second half 'the only way is up baby!' with 1300+ m of ascent on tracks and morraine. I'm tempted to try and arrange a shoe swap at the halfway stage: Kayanos followed by XA Pros. Looking at the photos from last years event there seems to be a lot of road shoes being worn on the morraine.
I found an account of the Jungfrau in which the author had analysed the times of previous runners and compared them with their 'normal' marathon times. It seems that the price to pay for the ascent is a 47% increase in time. As I'd fancy my chances at a sub three hour marathon (assuming I actually trained) I'm setting my target at sub 4:30.
So, the plan is a steady 1:40 for the first half leaving me fresh (I wish) for the second half. This will leave me with 2:50 for the second half which means a better than 4 miles per hour pace. I've finally gotten round to calculating the average gradient for the second half. Seems I've been overdoing it by training at 15% incline as 6000 ft of ascent over 13 miles gives an average gradient of 8.74%. So, I'll now, thankfully, be training at 10%. I was getting worried over the 15% regime as I struggled to keep up 5mph for a mile. Hopefully, 10% will be a lot more doable. As it happens I did some treadmill intervals on Tuesday of 7mph at 10%. My heart rate was 143 bpm which means it's not (yet) sustainable for me but there's still time to work on it. So, 5mph for the second half should do it. Easy peasy.
Just need to shed a few superfluous pounds now. Sorry Rosie but the love handles have to go ;-)