A newly revealed Apple patent describes a "Music synchronisation arrangement" for portable music players.

The patent was filed with the US Patent and Trademark Office on November 24, 2004. It explains: "The invention pertains to a computing device that is capable of controlling the speed of the music so as to affect the mood and behaviour of the user during an activity such as exercise."

It explains two ways the technology can regulate the music it plays by speed to match the pace of the listener's activity. In one way it matches the listener, in another use it can be controlled to drive that pace up, or down.

The patent also describes technology to change a song's tempo, or to choose a song by the tempo it has - to match a walking pace, for example.

Apple this week revealed its first athletic iPod solution that it has developed in conjunction with Nike. This solution consists of a sensor and transmitter in a set of Nike trainers, and a receiver connected to an iPod nano.

When the system is set up, it offers users information on time, distance covered, calories burned and pace that it makes visible on the iPod's screen, with real-time audible information on this also available through the headphones. The solution uses a proprietary form of Bluetooth to transmit this information.

Apple has a growing presence in the sports market. Its iPods were highly visible during the Winter Olympics, and sports assessment software SportsCode means Apple notebooks are nowadays frequently seen in the hands of team coaches during rugby, hockey and soccer matches worldwide.