Hi, I posted in here a couple of hours ago about Tower Ridge in winter and have decided to aim towards it. I'm fairly fot but hoe would I go about training for this? How would I train my stamina for such a long day?
Do it in summer conditions. Learn the easiest way to get to the Douglas Gibson Chimney at the start, recognise where the eastern traverse starts (And where the sparce protection is here), familiarise yourself with Tower Gap and practice navigation down off the summit plateau.
All of the above will assist you come a winter attempt.
Not sure if you mean you are fairly fit or fat. Best idea would be to get hill fit - hillwalking with your winter pack on so you are used to the weight and have some energy in reserve in case things go wrong. As above, do it in summer so you know the route and how to get off in bad weather.
Maybe find a partner who has done it or consider getting a guide.
Might be worth giving a couple of easier ridges a go in winter before you do it, Castle Ridge or something similar.
Read a report a while back by someone aiming to do Tower Ridge and they did a couple of similar routes before to get their eye in and learn the ropes.