Some say that the Nike+ ecosystem is modelled after North Korea. Whether or not this is true, the fact remains that it is an extremely closed system and Nike does not offer individuals any way to download their hard earned workout data. Neither do Nike provide third party developers access to their APIs so that data can be transferred freely from Nike+ to other services.
This means that RunGap and similar apps and services relies on undocumented and unsupported methods in order to help you fetch your data from Nike+. For some time this has been working fairly well - but since the introduction of “Nike Running Club” the service have been unreliable at times. Users have reported new workouts not showing up in RunGap or only showing up days or weeks later. Others again have reported missing maps for their workouts.
If you have been so lucky to get most of your data out of Nike+ already, this is good time to start looking for an alternative solution that doesn’t imprison your data this way.
As long as the current method can help at least some users to move their data away from Nike+ it will be kept running - but if it breaks down it will not be fixed and Nike+ support will be removed completely.
It is possible to send workouts from RunGap to Polar Flow and have them sent to Nike+ automatically: https://www.polar.com/blog/polar-flow-now-connects-with-nike-run-club/