BT audio dropouts when pebble runtastic app running

When using runtastic with my pebble watch which displays data on the watch my Bluetooth headphones dropout. The dropout is reflected in the bt icon (it switches to showing an empty battery icon which is what shows when only the pebble is connected) and triggering the select button on the headset then causes it to reconnect to the phone and then I can continue audio.

The dropouts happen continuously but with seemingly random time between (perhaps it occurs when the pebble data to display is updated??)

Closing the runtastic app on the pebble watch appears to stop the dropouts.