My name is Andy Palmer and I own White Star Running. We organise trail events, from one-mile kids’ races up to marathons and beyond. These are some of the questions we are often asked.

How do we plan a new race?

A marathon is 26 miles and 385 yards. Well, road marathons are that distance, as most are officially measured. But if you organise a trail race, things become a bit more flexible. That exact distance is very difficult to achieve if you are running over rights of way, national trails, hills, mountains paths, through streams, over stiles and around the beautiful British countryside. Generally, the off-road world happily accepts that trail running isn’t an exact science, and trusts race organisers to be close enough. However, woe betide the race that comes up below the 26.2-mile distance – people want over, not under. More miles for your entry fee is a good thing. We tend to use the term “ish” for our race: 26.2-miles-ish, half marathon-ish. It’s a get-out-of-jail-free card when the “marathon” is an extra mile or two.

How do you decide where to start?

The first, and the most mundane, thing we have to consider when route planning is, “Have we got enough parking for all the runners?” That’s before we look at any routes. Then we need a decent area for the start/finish, safe routes in and out of the area, access to water, shelter – and dozens of other things. All races need a good base camp. So once we have a base, we get the Ordnance Survey maps out and the fun really starts.

We look for major roads that we need to avoid, safe routes to run and whether we need to cross private land. We ask ourselves, “Would we want to run here?” Dorset and Wiltshire are smashing; it’s a good bet that it’s going to be scenic, and nice views are a really good selling point.

Facebook Twitter Pinterest Arrows mark the way through a field. Laying out the signage can take days, and a couple of teams Photograph: White Star Running

Once we have an idea of a race route and a good HQ, we ask the all-important questions: “How far do we want to run?” “Are we creating a marathon or ultra marathon?” “Can we create a half or 10k or 10-mile race?” ‘Can we set up aid stations easily?” “Can the ambulances and medics get to people?”

So, now we have the kernel of a race route. Next we ask, “What time of year?” We hold a lot of races in the summer and it’s back to that mundane issue again: parking. Finding hard standing in the countryside for 1,000 cars is difficult in January. We are lucky that the races we do hold in winter – at Larmer Tree Gardens in Wiltshire and the Tank Museum, in Bovington, Dorset – have access to dry parking.

How do you measure the routes and mark them?

With all that in place, we then need to get out and check the routes. We have walked and run our race routes many times, and have seen many parts of the country only a hardened rambler would see. We then measure them, mainly with GPS watches and online mapping.

We create a race plan with directional signage (a wooden stake in the ground and arrow pointing, hopefully, in the right direction). Our trail races tend not to have mile markers, as they are hard to lay out; one person’s mile five is frequently someone else’s 5.3 or 4.8. We go on foot to lay out the signage – this can take days. The Larmer races, for example, take two teams three days to signpost.

How do you work out the logistics for each runner?

We position aid stations approximately four miles apart. We use clean water containers and recyclable plastic cups instead of bottles, to cut down on waste. As a rule of thumb, we have three cups of water for each runner; on a hot day maybe more; our water containers hold 75 cups of water. For a race of 500 runners, we would need 10 20-litre water containers for every aid station. With five to seven aid stations, that’s a lot of water to move.

During the Giants Head marathon last year we used 1,200 litres of water, 9kg jelly babies, 6kg of jelly beans, 1,500 gels, 100 litres of flat cola, 4 bottles of homemade blackberry vodka, 12 giant watermelons, four dozen oranges, 66 pints of our local brewery’s beer, 66 pints of Dorset cider, 13 family-size packs of pretzels, nine giant packs of crisps, 63 packs of Jaffa Cakes and 600 portions of cake.

Facebook Twitter Pinterest ‘Keep mooo-ving … don’t mind me.’ Photograph: Oktay Ortakcioglu/Getty Images

What are the obstacles?

It’s not easy running in the countryside. We work with the farming community and try to fit our races in with them. At a race this year, a concerned farmer rang me up at 6am: “Morning Andy. Dave has escaped; we are dealing with it.” Dave is a massive British White bull. A herd of cows had decided to escape from their field, and seeing them walk past his field, Dave decided to join them by demolishing a barbed-wire fence. Unfortunately, Dave and his harem were now at mile 19 of our race, and the first runners were due to arrive at 10.30am. They managed to tempt Dave out of the field at 10.15am.

At the Larmer races last year, a tree fell down on the race route. Time for a quick Plan B; we frantically re-routed before the farmer who owned the land called to tell us he had shifted the tree out of the way for us. So it was back on to the re-routed bit– back to Plan A.

We re-routed the Ox half marathon and found a hill we called MOAH – the Mother of All Hills. MOAH is so steep that even the sheep walk around it. We made 400 runners go up it. They thanked us … sort of.

When I wrote the race instructions for the Bovington races, which takes place on tank-training ground, I had to tell the runners not to pick up anything that looked as if it could explode … And on the first year of the Ox races, we had to re-route the ultra marathon the day before the race, as flooding had created puddles 100ft long and 4ft deep. We have to delay the start of the Invader races every year because everyone want to take photos of themselves dressed as Romans.

Trail running is great.