There's a secret hero among the crowds taking place at this weekend's Cardiff Half Marathon, and it won't be running.

The humble plastic bottle, many of which will be handed out to thousands of runners during Sunday's race day, has a great deal of potential energy stored within it.

In fact, if everyone recycled the plastic water bottles handed out during the 13-mile run, we could generate enough energy to fuel parts of everyday life in Cardiff, including some of its most iconic landmarks – many of which are seen on the Cardiff Half Marathon route.

Here are just eight examples.

1. Your breakfast

Recycling just one bottle saves enough energy to toast nearly three rounds of bread. That’s enough to last you nearly a month!

2. The Principality Stadium

If 22,000 of us recycled one plastic bottle, around one for every Cardiff Half Marathon runner, it could save enough energy to power the Principality Stadium's floodlights for three years. 6570 rugby matches to be exact.

3. The Cardiff Bay Barrage

It's one of the Cardiff Half route’s biggest landmarks, and recycling just 170 bottles could save enough energy to power the enormous barrage for an hour.

4. Wales Millennium Centre

Reycling 9,668 plastic 500ml bottles saves enough energy to power the Wales Millennium Centre with electricity for two hours. That’s enough time for the Welsh National Opera to perform Macbeth from its latest season.

5. Roald Dahl Plass

The entire Roald Dahl Plass could be powered for one whole hour from the power of 100 recycled plastic bottles. As the namesake once said: "a little magic goes a long way".

6. Your smartphone

It's not just water bottles you'll find in the runners' hands in Sunday's race that can be recycled for energy potential.

Just half of the peel from a banana, once recycled, could generate enough electricity for a full smartphone charge. Bring on those running tunes.

7. Your children's school

If every person running in the half marathon recycled one bottle, it would save enough energy to power a typical school for two days. That's true brain power.

8. Cardiff Castle

Don’t have the cash for your own castle? What if the running costs were lower? If every runner recycled just one bottle, it could save enough energy to power Cardiff Castle with electricity for 55 hours.

Congratulations to anyone who’s out there running this weekend, or any time for that matter

Recycle for Wales wants to encourage everyone to recycle more to help Wales meet its recycling targets and continue leading the way on recycling in the UK.

Don't forget about the 'Unusual Suspects' - a band of household items, such as toilet-roll tubes and bathroom-cleaner bottles, that often fly under people's radar, creeping into the waste instead of the recycling bin.

Find out more about the ‘Run Refuel Recycle’ campaign and how recycling can help to keep Wales running on its website or follow the #RunRecycle conversation on Twitter.