They fall out of the ear if you try to walk never mind do any sport. They are just too bulky. You may notice that there is one star for this review, I tried to give it NONE but the Ciao review form forced me to give one star. If I could, I'd revoke it. I'd like to write something nice but nothing comes to mind. They are definitely NOT good value for money. One last thing, the cord splits within about two weeks of normal usage (walking, jogging around the park, etc). I have recently come to understand that this has happened with many other people. In reality this is a very poor product and should be discontinued by the manufacturer.
 

The sound quality is okay but the ergonomic design of these earphones is really very bad. When use them while jogging they just fall out of the ear. I have to wear a headband over the ears to keep them in the ear and even then they continually fall out. At first i thought I had an abnormal ear size but when i compared them to my Sony, Apple iPod & Phillips earphones I very quickly realized that the ear buds on the Sennheiser MX70VC Sport Earphones are too large and the in-ear fit is badly designed. The ergonomics are dreadful. It's a pity because I have, in the past, associated the Sennheiser brand with good a certain level of quality but what use is sound quality if you can't hear it because the earbud it doesn't stay in the ear.