Gym-friendly earphones have typically been referred to as such because they either stay firmly in place or endure physical abuse without immediately dying. And in the past, Sennheiser has made respectable earbuds for exercise, but a new partnership with Adidas takes workout listening to a new level.

Excellent audio performance with strong bass response; Comfortable fit; Stays in place even during intense workouts; Waterproof, sweat-proof.

Some cable thump when running; Neon yellow color won't appeal to everyone.

I liked these headphones well enough before the right earbud stopped working, but for this kind of money, other factors should be fined tuned. Factors such as: length of the headphone wire (either too long or too short), the heaviness of the volume control (when you run, the weight of the volume...

Weighing in at just 14g these Sennheiser CX 680i Sports are lightweight and compact. The 1.2 metre cable is super thin but still manages to come with inline controls and microphone built-in, so it's perfect for use with your iPhone as well as your iPod.

The Sennheiser CX 680i in-ear headphones are a decent set of not-quite-mid-range headphones with a remote & mic. They're not quite as rugged as we would've expected from a set of in-ears aimed at the gym crew, but their crux fins (the rubbery things sticking up out of the ear buds) definitely help...

This really is a great set of in-ear sport earphones. The noise cancelation is really good, I used it while biking and on public transportation too - had no issue with outside noise.

Great noise canceling; Sweatproof; Water resistant; Volume control

No mic; No Skip/Play/Previous buttons; Awkward volume control position; Symmetrical cord

Light, comfy and great sounding – a worthy winner of our favourite training buds

Keeping in-ear headphones firmly in place can often be a bit of a problem, especially when you're working up a sweat, so the earpieces on the CX 680 can be fitted with a pair of flexible rubber ‘earfins' that fold inside the curve of your ear and help to keep them secure.

Good sound quality; ingenious ‘earfins' designed specifically for runners

Cables can get tangled; microphone only on CX 680i model

Sound quality and fit are as good as advertised really nice feel unfortunately the headphone quality itself is not so good, in my particular case i sometimes the sound cuts off if you touch or shake the connection jack, there's seems to be a connection issue.

I have to say I am disappointed in the sound quality of these headphones. They are tinny & give a poorer sound than my much cheaper JVC ones. They are truly strongly constructed and stay in the ear for sports but that alone is not enough.

Great Service by the vendor hats offf Superb I am highly impressed by the service the vendor has provided. Great