Working out your thumbs may be the text big thing.

British cell phone provider O2 has come out with “thumbells,” which are just what the name indicates – dumbbells for your thumbs to keep them in shape.

The company is getting ready to launch a 4G network, which will let users use their phones and an increasingly fast level. And that means their thumbs will be asked to do even more than now.

In an attempt to make sure thumbs are up to the task literally at hand, O2 hopes the thumbells keep their appendages in tip-top shape. One survey found more than half of all people with smartphones have complained about thumb pain by using their devices.

You can see a cheeky commercial for O2’s ‘Fir for 4G’ campaign below to help you decide if this is genius or just the thumbest idea you’ve ever heard.

If you’d like to test the thumbells, you can create a Vine using your thumb and send it to O2’s Twitter account.