It does not appear they are adding any more sports modes, that is what they added Freestyle and gym modes for. Freestyle is for any GPS enabled non-core activities and Gym for non-GPS enabled activities. If they start adding sports modes then you may want in-line skating and I may want football and someone else may want paddle sports, this is why then went with the generic Freestyle. The existing sports also tie into the lifetime totals on MySports. If they add more sports modes they would also need to redesign all of MySports to capture them. You should try using Freestyle it gets you distance based on GPS and calories based on HR so it will be the most accurate (cycling and running use METs for calories and ignore HR).
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