There are various degrees of lunacy when it comes to running. Consider the following series of ever-increasing insanity:
That's mountain marathoning!
Fell running might seem mad enough but two days of it with a rucksack on your back and only a map and compass to tell you where to go? Strange as it may seem mountain marathons are very popular and the country's biggest two (Saunders and Karrimor) always reach their entry limit of a few thousand pairs very early. They are a cross between fell running, orienteering and hill walking. You have a list of around half a dozen checkpoints to visit in order as quickly as possible while carrying enough kit to keep you self-sufficient for two days, including the overnight stop - so you have to carry food, stove, spare clothes, sleeping bag, sleeping mat ... and a tent! Most regular MMers get their rucksacks down to between eleven and thirteen pounds although the lightest I have heard of was six pounds! Running in pairs helps as you can share the load of tent and stove (sleeping bag as well if you're really good friends!).
Courses generally range in length from about 15Km to 40Km but that's the straight line distance between checkpoints - convert kilometres to miles and you'll have a pretty good estimate of the true distance covered. Of course, that's over rough terrain with a lot of climbing (not to mention raging torrents which have been known to sweep competitors downstream) so you are generally out for between four and ten hours each day. Navigation is harder for the longer courses but can be tricky in poor visibility for everyone.
The weather can be pretty adverse. I have seen sleeping mats ripped from people's rucksacks in high winds and I've ascended snow slopes to be greeted by a whiteout at the top. At one event 95% of the competitors retired before even getting to the first checkpoint (that was the one with the blizzard). On the other hand I've also been burnt to a frazzle in seriously dry conditions.
Mid-way campsites range from relatively luxurious (i.e. a flat, stone-free field with portaloos) to the downright bleak (a high-level, windswept hillside with a trench!). On occasion I have seen showers but it is more usual to finish a mountain marathon smelling like ... well, you know how smelly you can get after a normal run so imagine what you're like after two days, having slept in your running kit as well! Luckily most of the smell is in your clothes rather than you (it's the bacteria in the dead skin that flakes off) so a quick wash and change has you reasonably fit for travelling home afterwards.
But why? Heads and brick walls come to mind - it's nice when you stop! Moving quickly over the hills is always a good feeling and hitting a particularly tricky checkpoint spot on in poor visibility gives you a real buzz. The highest high, though, is when you come off the hill and see the finish below you and think of that hot cup of tea waiting just for you!
I suppose that all makes mountain marathons sound worse than a Grizzly full of beach but they can be quite enjoyable ... honest! Many people run very little of the course (maybe just the easy descents) and some courses are purely for walkers. One of my most enjoyable events was the first one I did with my wife, a short course (but not the shortest!) in Scotland's Galloway Hills - we had a very pleasant couple of days ambling through superb scenery with a mid-way campsite beside a loch in the middle of nowhere. Wonderful!
Postscript. My own best result in a mountain marathon was second in the Saunders Scafell class in 2000.