Norwegian Professor Thomas Losnegard recently published a study comparing different pole lengths for double poling.
Nine athletes were subjected to two 1000 m tests at a 2.5% incline on a roller ski treadmill, one with poles that were 84% of body height, the other with poles that were 88% of body height. With the longer poles, the subjects consumed less oxygen, however the difference translated to only about 1%, which, according to Losnegard, one could not see or feel.
In comparing this study with two other studies which looked at different length poles on varying terrain (as opposed to just a gradual uphill, which was the case in Losnegard’s study), the general consensus is that slightly longer poles are best for double poling at low to medium speeds (i.e. on uphills and slower flats), while the shorter poles are better on faster flats and downhills.
Original post: ski-lines.com