Apple is tightening up its privacy rules to ensure a new generation of health and fitness apps is not thwarted by growing concerns over how developers use personal data.

The rules will stop data collected through Apple’s new HealthKit platform being used to target ads for products such as weight-loss remedies.

HealthKit, which will track data including exercise levels and sleep, is one of the key features of a new mobile operating system that will be launched next month alongside new iPhones and a wearable device, dubbed the iWatch by pundits.

Shares in Apple touched a high yesterday after Apple sent out invitations for a media launch on September 9th, at which the group is expected to unveil the new gadgets.

The popularity of health apps that track intimate data such as heart rate has spiked in the past year, but regulators and privacy groups have found some developers pass user data to advertising networks, often without telling the customer.

In a new set of app store rules, Apple say developers must “not sell an end-user’s health information collected through the HealthKit API [application programming interface] to advertising platforms”.

The clampdown comes as Apple seeks to differentiate itself from its rival Google, which relies on targeted ads for much of its income.

In June, Apple unveiled its Health app, a new dashboard that allows iPhone owners to track heart rate, calorie intake, movement and other fitness metrics from different apps in one place. Underlying the dashboard is the HealthKit system, letting developers contribute data from their own apps and draw on information from others if users grant permission.

Developers who want to tap into HealthKit must commit to the rules.

HealthKit apps must not use the programming interface or any information obtained through it “for any purpose other than providing health and/or fitness services”, the new rules state. – Copyright The Financial Times Limited 2014