Climbing up a Steep Hill
Ken’s Story
I thought I knew that the only way to hold my grip up a steep hill was with aggressive hops to stomp the ski into the snow each time one of my feet landed -- or else walk up with herringbone. Then I got to see myself on video on snow at the Silver Star camp in British Columbia, Canada. It looked so much more aggressive than any of the other amateur racers -- but clearly my aggression was not more effective. So I started looking for the "secret" of holding grip up a steep hill. To really focus on that, I spent a lot of time skiing up long hills without using any pole-push: legs only. I found that once I took away the ability to "fudge" with help from the poles, there was no way to hide from what was not working. I tried a variety of "tricks": complete weight transfer side-to-side, more ankle bend, bending forward at the waist, different cadences (and along the way discovered one of the other "secrets", about pressing the toe on the center of the "wax pocket"). I watched slow-motion videos of elite racers. And I did my usual thing of posting a question to the rec.skiing.nordic discussion group. It was Scott Elliott who patiently clarified to me that the best technique was to bend forward from the hips. A subtle point, but I think it gets me a little further over the new ski than bending from the waist. One idea I saw several people try to apply was that technique for steep uphill should try to be as much as possible like classic striding on gentle terrain. But after I spent a lot of time looking at elite racers in slow motion -- and thinking about the physics -- my analysis led me to the conclusion that the technique for steep hills is completely different -- for the reasons given below.
What are the differences?
Major ways that steep hill technique is different from striding on gentle terrain:
I must focus on maximum effectiveness of the strong leg muscles Because the energy demand of maintaining momentum when climbing a steep hill is much higher than on gentle terrain. The more times per minute the strongest muscles push with effective leverage in the strongest sub-range of their motion, the more power is delivered. Therefore . . .
I increase the cadence of my leg-pushes Because the alternative of lengthening the range of motion of my big leg muscles would: (a) put more stress on my leg muscles and joints; (b) use the muscles in ranges where they deliver less effective power, which would reduce my power output averaged over my whole stroke cycle. Increasing cadence in turn requires that I must (a) shorten the pole-push duration to match the leg-push phase; (b) reduce the time of the glide phase.
extra down-force beyond body-weight is OK, even required. Extra down-force beyond body-weight is often required on a steep slope, in order to provide enough total down-force on the grip zone to avoid slipping back. It is OK to apply this extra down-force, because the minimization of glide makes it possible to get most of the double benefit of extra down-force ("landing" down-force as well as "launch" down-force) from the double cost of extra down-force. If a large enough extra down-force is applied, then the reactive force can launch my body up into the air. But this is not necessary for this technique -- see more on this. I make no attempt to maintain glide Because glide is no longer necessary now that the speed is slower Because a longer glide phase interferes with higher leg-push cadence, and it interferes with getting the double benefit from the double cost of extra down-force.
my pole-push is nearly simultaneous with the opposite leg-push. Because the pole-push must be shortened to fit into the time of the leg-push, so it does not prevent higher leg-push cadence. Because the pole must be in position to instantly resist slipping back at any time during the leg-push phase -- critical because loss of momentum occurs so quickly on a steep uphill, and the muscles are already so near their limit that the impact of the additional energy needed to regain momentum adds major stress. Because this way the pole timing for the hill bound is the same as for the herringbone -- so I can switch between the two motions smoothly as needed. Some elite racers start the pole-push just an instant before the new ski lands. In any case, a key function of the pole-push is to solve the problem of the upper body falling behind the grip wax zone of the new ski -- by pushing it up and forward. This simultaneous timing of pole-push with leg-push has a cost: The down-force component of the pole-push has a reactive up-force on the skier's body, which interferes with the down-force needed for best grip. Fortunately the double benefit of extra down-force is now available (due to the minimization of glide). And the forward-force component of the pole-push itself reduces the level of leg-push forward-force needed -- so there is less need for so much grip and down-force to support it against slipping back.
Secondary differences
I reach my new kick leg to land way up the hill, and start pushing with it as soon as it lands. This "fills in" the time that would otherwise increase the glide phase. It effectively utilizes the "landing" down-force from the up-and-down motion of the upper body -- so it helps get the "double benefit" from the extra down-force. This technique mainly uses the hamstring muscles in a good motion sub-range for them, so it does not add stress to the big quadriceps or gluteus muscles. I've got lots of pole-push strength to assist the momentum of my upper body to help it "catch up" with foot up there. Skiers with less leg and arm strength reach their leg less far up the hill -- take smaller bounds, perhaps more like bouncy steps. Or they just use herringbone. To avoid slipping during this sub-phase of the leg-push, I find it helps to use the press the toe "secret". Bending forward strongly from the hips sets me up to quickly get my weight up over the grip zone of my new ski. If I get caught with my weight back on my heel, the new ski slips back. Basic physics says that I can temporarily "fool" the ski into feeling my weight on the grip wax zone by pressing my toe. But to sustain the focus of force through the center of the grip wax zone, I need to get my body's center-of-mass centered over it. Elite racers in the videos I've seen maintain a steady, quiet, and large forward lean all the way up a steep hill. They reach way up the hill with their new ski (so that their ankle is definitely not flexed) -- which leaves their hips and legs behind the new grip zone temporarily. (This is another way to lengthen the leg-push time -- see the "secret" of Smooth Striding). But this forward lean at least keeps their upper body near the new ski, and down-force into the new grip zone from the impact of their landing helps hold the grip temporarily. Then they use their momentum and the help of the pole-push to quickly get their whole body weight centered over the grip zone of the new ski. But some coaches say just the opposite: Straighten up more as the hill gets steeper. This may actually be helpful for some skiers -- see more analysis of this question.
Bending forward a lot can strain your back. So you're asking for trouble if on one day you greatly increase the amount of time you lean forward, the number of times you lean forward, and/or how far you lean forward. Leaning forward works, but you have to train your back carefully for it, build it up slowly over several weeks and even months.
I plant my pole tip further back: behind the heel of my boot. Because planting it further forward would apply more up-force to the skier's body, which would counteract the necessary down-force to achieve sufficient grip to prevent slipping back. Because planting it further back focuses on the low-gear, higher-force sub-range of the poling motion. Because angling the pole further back ensures that it is already in position to instantly resist slipping back -- in case the grip of the ski fails. Because I need to use a shorter pole-stroke length to allow higher cadence for maximum effectiveness of the powerful leg muscles.