If you're of a nervous disposition, stop reading now. The most dread-inspiring place at a marathon isn't the start line, or even the 20-mile marker, but the Portaloo queue. I'll admit, though, that while in a line for the loos at my first marathon in Berlin, the sight of lots of blonde ladies discreetly watering the bushes in the Tiergarten brought a smile to my face.
After all that hard training, the need for mid-run bathroom breaks can make or break your race. While the pre-race jittery Portaloo dance is unavoidable, as your body prepares for fight or flight, often what you eat (or don't eat) before or during the race will determine your ability to make it to the finish line in comfort, without needing to hurtle into a bathroom mid-run (or worse, over a ditch into a field, as happened to a friend of mine).
During hard or long efforts, the blood flow to your gut is reduced, which is why runners often tend to have problems with cramps and nausea. Practising your eating strategy before and during training accustoms your stomach to handling fuel during the hard effort of a race.
More than any other aspect of running, figuring out triggers for stomach issues is very individual. What works well for one person will have another doubled up with cramps, so you'll need to execute your own personal nutrition experiments.
I used to religiously eat porridge for long training days and races. With all that lovely soluble fibre, combined with a cup of strong coffee, it was a recipe for many pre-race bathroom dashes, so I switched my race breakfast to scrambled eggs and toast.
I usually aim to have my breakfast and coffee around three hours before lining up for a race, giving time for that essential pre-run bathroom break.
If you have trouble with mid-race cramps due to what you've eaten, work out how much fuel you need to race successfully.
For shorter distances, like 5k or 10k, you don't need to eat much before at all – a good dinner the evening before goes a long way towards fuelling your muscles. I know some runners who don't eat at all on race morning up to half-marathon distance.
Likewise for shorter races (under an hour) you don't need any mid-race fuel, but experimenting with your energy intake is vital for longer races.
Some people can tolerate sports chews or energy drinks but not gels; others find that only some brands work for them.
The wall in the marathon is partly about how well you have fuelled in the first 20 miles, so it's worth a bit of persistence in finding your own personal recipe for success.
The eternal dilemma for morning long runs is how late I can get up, eat and (kind of) digest breakfast before starting to run.
Breakfast stayed in place nicely. A gel every 10k (a delicious salted caramel Gu and a chocolate Accelerade gel) kept the wolf from the door, as Kayla paced me through the last tired miles.