I agree that an interval training function would be great - but I would like to see it in different flavors:
a.) Distance interval:
The training changes from one interval to the next depending on the distance reached. E.g. 1km run, 500m walk, 1km run ...
b.) Time interval:
Training style changes depending on time: E.g. 5 min run, 1 min walk, 5min run ...
c.) Speed interval:
Interval changes if average speed of the interval reaches a certain level (needs to be combined with my earlier proposal of having a sliding average of the last 1000m):
E.g. interval changes if average of last 1000m is higher than 10km/h, then changes when falls below 5km, then changes again if again over 10km/h. Instead of speed you could use the pace here obviously to set the borders.
I have a polar watch as well and it implements a.) and b.) but I think c.) would be really unique so far and make a outstanding feature.
Best regards - P-eter Weiss
PS: Somehow the forum does not like my fist name - it always replaces the characters, is this a bad name? :-)