Not dis-similar to The Big Five Marathon http://www.big-five-marathon.com which I ran as my first marathon this year, actually not as hard as you think. Basically it's going to take you x amount of time more than normal and if you run as a sensible pace and don't go out to hard then you will be fine.
Yes you probably need to follow these recommendations if you are going for a record time but then you don't do these type of marathons for time but for the fun of completing them.
So 10 people from the UK were amongst 100+ runners who took on the insane challenge of the Big Five Marathon in South Africa on 21st June 2014.
If you are thinking about doing it in the future - do it - it is one amazing race. The elevation gain is between 1050m and 1560m depending on if you use Strava or Runkeeper but basically it has a lot of up and down.
The first 1km is downhill but like most of the race there is always an uphill in there somewhere but it's mainly down. Then you reach the bridge and it's climb at 30 degrees to about 3.5k where it flattens out a bit for a rare good track which is flat and solid. Then it's the 6k marker and a nice 4k uphill slog on bolder strewn sandy tracks to the 10k marker and turn back down. An easy decent but no rhythm as you avoid the rocks or holes and onto the flat at 14k for a km then you are ready for the decent into hell. 4k of downhill at an average of 45 degrees and in parts 50/55 degrees steep. The first 2k is in soft red sand and rock but the final 2k is so steep they had to cement the "road".
You reach the bottom and for 300m life seems great, the road is flat and solid and then you turn the first corner and see the sand which is to suck out the energy in your legs for the next 7k. Did I say it also started to climb and would roller coaster all the way round this 7k loop.
Then it's time to climb - quite literally - the hill from hell. In places 55 degrees and at altitude of 1400ft walking is hard work and I had to stop every 10/15 small steps to gasp for breath. 1k took me 24:40 the slowest km in history and the only time I felt I could not make it. The hills crest and you thing that is the last one but every turn seems to bring another 200/300m slap of hell to climb so it's a relief when half way up you hit red sand and you know you have made it.
4k later and the hill tops out and we are at 30k and a gentle run down to 35k when the road gets worse, then at 35k its a turn for home and up up up. The road is so bad the drivers say it's too difficult for the 4x4s and we reach 39k to be met with a hill of boulders. This really isn't a trail anymore it's just a sadistic joke to break your ankles. A few more ups and the odd very steep down and the last 1k flattens out to resemble a trail road again and it's a dash for the finish line.
Truly one of the toughest marathons in the world (only 15 were sub 5 hours) but one of the most amazing you will ever run.