If you're not aware that you can't run in open-road races, then you're in for a sad time during your upcoming 10K entry.
But thankfully you can still use music, as long as you're using bone-conduction headphones – and the latest from Aftershokz (the most prominent brand creating this tech) are the Sportz Titanium.
At the London Marathon Expo we got a chance to try out the new Aftershokz Sportz Titanium, having been fans of the wireless Trekz models in the past.
(On a side note, the constant use of the letter 'z' by Aftershokz is making our eye twitch).
These things are seriously light – and given they only cost £60 / $60, they feel brittle in the hand.
But these things are strong (hence the use of the word titanium in the title), and the weight is great for when wearing them during a run.
The main difference here from Aftershokz is that the headset battery has been moved towards the headphone jack, taking away weight you have to wear around the head.
With the Trekz Titanium the batteries are, obviously, locked into the headband, but moving them away means you're left with a super-lightweight set of headphones that fire sound into your head… but not through your ears.
They work by using soundwaves that vibrate through your bones, conducting the sounds into your ear drums and leaving your ear-holes open to receive important commands about not running into traffic.
The design is sleeker around the bud as well, with circular pads looking a little more attractive on the head – and still offering the same vibrating feel on the sides of your face if you crank the power up too much.
It's hard to say too much more about these headphones – it's surprising, perhaps, that they need such a big battery pack, as you might have expected them to work from the phone's headphone jack… but clearly the bone conduction needs a bigger engine to drive it.
Everything else works as you'd expect – if you've not tried bone-conduction headphones before, the sounds quality isn't anywhere near as good as a pair of noise isolating buds, but that's kind of the point.
It's when you put your fingers in your ears that the jaw-dropping moment happens – you can still hear the music clearly despite locking out the ambient noise.
However, the soundwaves aren't super-targeted into your head, so there is some sound leakage – we wouldn't recommend these for your morning commute.
For the price, these headphones are great – and you can save a few pounds / dollars if drop the inline remote and just go for straight music playback, which (given these are race headphones) makes sense to us.