health app not recording data
the health app on my iphone 5 doesn't record any data
iPhone 5, iOS 8.4
Do you have apps installed that support that on your device, for example Nike+ Running or similar?
Has the phone recorded data before the update? If yes, try to reset the phone by holding the sleep and home button for about 10sec, until the Apple logo comes back again.
You will not lose data by resetting.