In reply to RobScotland:
I have found all the following, among others, useful:
Ice and Mixed - Will Gadd
Ice World - Jeff Lowe
Extreme Alpinism - Mark Twight, (the Old Testament)
Training for the New Alpinism - Steve House (the New Testament)
The New / Old Testament bit is me being tongue in cheek - some of Twights endurance training ideas have been debunked by the ideas in House's book, but it is still full of good information.
Dave MacLeod's utube channel also has a good film on mixed training.
On a personal level I replace one of my climbing wall visits with a dry tooling session a week (on an old railway bridge) and up the running a bit through the Autumn. These DTing sessions are more about remembering what you can stand / pull on and how to stand / pull on stuff, than about fitness.
Post edited at 14:41