1. If you're doing it right you will look like crap.
If you go for a run and come back with a healthy sheen and a big smile you need to turn your ass round and do it all again.
If have been looking after small children and your clothes and hair remain immaculate you have not been looking after them properly. You have been letting them watch telly (don't worry we all do it) and not feeding them.
2. You can buy all the gear you want but it won't help you.
Both small children and running are supported/ exploited by a huge amount of companies and products but all the high wicking fabric in the world isn't going to make you a better runner.
The same with small children, you can spend literally thousands of pounds on plastic stuff from China but at some point it will boil down to you and a toddler going mano a mano.
3. It takes a while to get the hang of it.
After you've been doing either activity for a while it becomes easier.
But beware. This is often the point when folks do crazy stuff - like entering a tough mudder or having another baby.
Either way you are going to regret it.
4. Some people will think you're crazy.
Why would you put yourself through that? Is a question I get asked both as a mother and a runner. The answer in both cases is the same.
Because no one else is going to do it for me.
Oh hang on no it's not.
It's because I love my children and I love leaving my children behind when I go for a run.
5. At some point it will all get too much and you will decide you can no longer go on.
In running this is known as hitting the wall and can happen when you are covering long distances.
With small children this is known as 4pm Friday. Every frickin' week.
One of these situations calls for a sports drink and some positive thinking, the other gin. I'll leave it to you to work it out.
6. Some days you really can't be arsed.
But you are totally not allowed to say this.
I don't know why this is I don't make the rules.
If you are a runner and a mother the rules are that you must always want to be running and mothering - heck do both at the same time (don't I've seen people jogging with prams it looks weird).
I like going for a run, I love looking after my children but sometimes I really don't want to do either.
I just want to sit on the sofa and eat crisps in silence
Follow Kirsty Smith on Twitter: www.twitter.com/eehbahmum