1. When you sign up for a big race, you start to focus on race day. With pregnancy, that big date always on your mind is your due date (even though only 4% of babies are actually born on their due date - at least races tend to be more predictable!)
2. Marathon plans are in weeks & most runners can tell you exactly which week they are on. Once you find out you're pregnant then you also measure in weeks. You might not have a training spreadsheet but you'll almost certainly have an app telling you exactly what's happening to your body and your baby as each week passes.
3. You eat a lot! Training for a race uses a lot of calories and, believe me, so does growing a baby. In the first trimester all I could stomach for lunch was a white bread roll, babybel and ready salted crisps (eaten furtively at my desk so my colleagues didn't notice the weird new eating habit!) - maybe I was carb loading ready for labour?!
4. Lucozade features heavily. As part of standard antenatal care there's a glucose tolerance test which involves drinking a bottle of lucozade an hour before a blood test. Additionally midwifes recommend taking lucozade sport to hospital with you - I don't actually like lucozade but I'm glad I took their advice, the instant sugar got me through labour just like gels & jelly babies did in my marathon!
5. At the end of it all you might not get a shiny new medal but you get a brand new baby instead!