Run or walk your way to a FREE or cheap Franco Manca pizza

Franco Manca's 'Map My Pizza Run' promotion gives you £1 off pizza for every one kilometre you run or walk in one go between Monday 5 January and Saturday 31 January, which you'll need to record (or have recorded) via a fitness app. Your activity should be 'pizza-shaped' – so essentially, a circle or a triangle to represent either a whole pizza or a slice (see Franco Manca's suggestion below) – toppings are optional.

This means if you do a 3km run/walk you'll get £3 off a pizza, 5km would get you £5 off, and so on. But how far would you need to go for a free pizza?

I claimed a free £10 Margherita pizza

As I'm on a 17-week training plan for the marathon, I've my pick of January runs that would qualify me for a free pizza at 8km and beyond. At the weekend, I ran 18km, and although it wasn't entirely pizza shaped, I hoped they wouldn't turn me away considering that took me pretty much two hours to do. Well, my luck was in!

I turned up to Franco Manca and politely asked about the offer. Staff told me the run had to be either circle or triangle-shaped, and I pointed out the pizza shape that formed part of my run, and stressed I'm training for a marathon (in case I hadn't already mentioned that yet!). The manager came over and asked to see my run. It felt like a tense few seconds wait, but he smiled and asked what pizza I'd like. Result! Although 18km was enough to get me one of the more expensive pizzas for free, I opted for the £10 Margherita, which you'd need 10km for, so my effort more than covered it.

A few tips and things to bear in mind

• Run a route that's circular or triangular to give yourself the best chance of claiming. While the route I ran wasn't a neat, perfect circle or triangle, I think staff during my visit were feeling generous (that, or they were impressed with my 18km?).

• Make sure you show the run within your own fitness app. A screenshot from your runner friend won't cut it.

• We've heard a report of one restaurant saying the run has to be done the same day as claiming the offer. This isn't in its terms and conditions, and that wasn't the case for me (mine was four days after), but it's something to bear in mind to avoid disappointment. We've asked Franco Manca if there's an official line on this, but it hasn't got back to us.

• You can dine-in with this offer (you'll only get money off pizzas, not other menu items). I was able to take away my pizza, but Franco Manca hasn't confirmed this is the case with all of its restaurants.

This deal is about getting out and moving your body (Franco Manca say there's 'no pressure, no targets, no rules'). I would hate for anyone to equate running solely with burning calories so you can 'earn' pizza. Food is fuel and this offer is a good way to make a saving to keep your bank account fuelled too.

For more ways to combine running with free food, you can also get a bagel at B Bagel for running a personal best (PB) during January.

And finally, I'm running my marathon in aid of Cats Protection – a cause close to my grandma's heart, who inspired my running journey. If you'd like to, you can donate to my fundraising via JustGiving.