The side step on skis: edge uphill, climb the slope step by step without slipping back, with the herringbone as a faster option for gentle climbs.
In the side step you place your skis across the slope, edge them uphill and climb sideways – first the uphill ski, then you bring the downhill ski up after it, like on a staircase. That gets you a little way up without a lift, for example back to the practice slope or to a lost glove.
The German Ski Instructors Association makes the side step a learning goal of its own at beginner level ("Learning Level Green"): "climbing in side step" appears in its teaching-practice topics next to "straight running in a stable position" and "gliding and braking in the wedge" [1]. The herringbone step appears as an alternative [1]: the skis form a V with the tips apart, and you waddle up like a duck. That shows climbing is a building block, not an extra.
How hard is it? The movement is simple but unfamiliar. One morning on flat terrain is enough for most people to master it – that is experience, not a study figure.
Turn the skis so they are across the fall line, both parallel and the same distance below you. Your body faces the slope. If you are not across enough, the skis slide forwards or backwards.
Milestone: you stand across the slope without sliding.
Tilt your knees slightly toward the slope so the uphill edges bite into the snow. Those edges are your stairs. With flat skis you slide away as soon as you shift your weight.
Lift the uphill ski a little and set it down one ski-width uphill. It is now slightly higher than the downhill ski. Set it down on its edge before you put weight on it.
Shift your weight onto the uphill ski, lift the downhill ski and set it down parallel beside it. Pause. Then uphill ski again. The poles support you, especially the uphill pole helps balance.
Milestone: ten steps in a row without the skis crossing or slipping.
On gentle climbs you set the skis in a V shape (tips apart, tails close) and walk straight uphill on the inner edges. That is faster than the side step but costs more thigh strength and does not work on steep or icy slopes. Like the side step, the herringbone belongs to the beginner level [1].
Fix: knees toward the slope, uphill ski first, always stay at the edge.
Do not watch your skis, watch the stairs ahead of you. Plan three steps ahead: where do you place the uphill ski, where is hard snow? When you look up, you automatically stand more upright, and standing upright means your weight sits in the middle.
A practice plan for one session (practice, no study evidence):
Once you have done that four times, you no longer climb tensely but with rhythm – and save strength for the descent.
Place the skis across the slope, edge them uphill and climb sideways: move the uphill ski first, then bring the downhill ski up parallel. The poles are for balance. On gentle climbs you can walk up in a herringbone instead.
In the side step you climb sideways across the slope. In the herringbone the skis form a V and you walk straight uphill. The side step also works on steeper slopes; the herringbone is faster but more tiring [1].
Only at the edge. FIS Rule 7 requires skiers climbing or descending on foot to keep to the side of the slope [2].
Usually the skis are too flat or not across enough. Tilt your knees toward the slope so the uphill edges bite, and set the skis at a right angle to the fall line. On hard snow you must edge even more.
Straight Run: Skiing Straight Down Without Clinging On