We spoke to Steve and Cat, who trekked Kilimajaro in 2008, for their advice on preparing for the challenge:
We combined some short, medium and long walks in various locations to get our legs used to walking. This ranged from Cat Bells in the Lakes (about 4 hours) to Snowdon (6 hours) to Cambridge to Ely (a lot longer). The Ely walk was good because it was flat all the way (about 20 miles or so) but you could see the finishing point at the beginning. It gives mental strength as it seems never ending and it is the same with Kili. You just never think you are getting nearer but you know it is within reach and know when you are going to get there.
We quit smoking six months before (and started again on the way down...) and cut down on alcohol/bad foods.
Invest in good kit
Good footwear is I agree the best investment one can make; one girl came in trainers. Some brilliant boots, 1,000 mile socks (to stop blisters) and borrowing great things like good sleeping bags from family was essential. Walking poles are essential, especially on the way down to stop your legs seizing up.
Get used to wearing a rucksack. Some people on the trek didn't even know what all the various straps were for and this meant they were in pain as the settings are important and stop aching backs, shoulders etc. Any decent shop such as Cotswold will have guys who can show you the ropes or just watch a YouTube video as there are loads.
Know how all the equipment works as you will have problems on the trek otherwise. Have a big capacity water sucker thing as you need to drink litres and litres every day. Again know how to use it and repair it if necessary before you leave.
At the end of the day, all the people who made it to the summit took the altitude drug. Even people who are really fit don't always make it as altitude sickness does not discriminate between levels of fitness.
Be mentally tough
I would say mental toughness is the most important thing in succeeding. Whether it's a step machine, long boring walks or music in your ears, have some method of blotting out the pain, aching muscles or whatever. Cat had songs to sing as a group which took everyone's mind off what they were enduring.
Don't try and go too fast, it's a marathon not a sprint. Do lots of stretches so your legs and muscles don't hurt the following day. It will feel like hell as you're tired but it is essential.
Setting small goals on a long walk is a good idea, but I would break it down into time rather than distance: next half an hour etc.
At the end of the day it is an experience and an amazing one at that. Make friends, enjoy the views, get to know the porters and what they have done in their lives and take a zillion photos.
I (Steve) bitterly regret not making it to the top and know deep down it was a combination of my MS and my fitness that meant that was the result. I would however not have done anything any differently as I had an amazing trip, a life changing experience and made some new friends for life.