You Asked, We Answered: Health Apps & Technique

Are Health App Metrics Helpful in Improving Technique? 

Reader Question: This weekend I skate skied with a friend noticed a measurement on the iPhone Health app called Walking Asymmetry. He's been looking at this after going for a walk and the measurement is 2% or less. This weekend he tried it while skate skiing (mostly V-1 on the left side) and it showed 26% yesterday and more than 40% today (he tried poling more on the right today. I looked at mine and it showed 6% yesterday (mostly V-2) and 34% today (soft, new snow, more V-1 than the previous day, mostly poling on my left side). There is actual normal everyday walking included in these figures, but most of the activity is from skiing. 

* Why would skate skiing show such asymmetry?

* Is this normal or expected?

* Are we gliding longer on one side than the other?

* Is our cadence uneven?

* Is this measurement useful for cross country skiers

* If the measurement should be much closer to 0%, what can we do to improve the measurement?

Very curious to find out if this indicates flaws in technque. 

Answer: 

Very interesting question! 

Generally, I find that generic health apps are not very useful as metrics for Nordic skiing (or most higher level activity) unless they are directly plugged into your HR. For example, a lot of folks use their ‘step goal’ to determine activity level, but it’s really hard to determine what amount of steps equates to an hour of skiing, etc… 

As for the Asymmetry. I can’t tell you much about your technique without seeing it, and I very much doubt that Apple knows more than you do about how to ski well! A few things that I would be skeptical about in terms of data accuracy:  

1. Is your friend skiing with his Iphone? Or is the app connected to a watch? 

2. What wrist is the watch on? 

Let’s go over V1 Basics: 

A lot of skiers rely too heavily on one side or the other when they are skate skiing, especially V1. We often have a strong side, which can lead to the ‘dead arm-peg leg’ effect. You have probably experienced this, especially on steep terrain, slow or heavy snow, where you feel like you are stomping down on the poling arm and leg, and barely getting any power out of your ‘off-side.’ This is likely what you are seeing reflected in the data. Especially if you are using your off-side and are not as comfortable gliding evenly on both sides, that would explain the increase (that 40%) in the asymmetry reading. 

Regardless of IPhone data, here are some great ways to work on your V1 symmetry that are going to be far more effective and tangible for you: 

1. No-Pole drills: This is my go-to. While V1 has a bit more asymmetry, we still want to try to glide as evenly as possible on both skis as we are going uphill. No-pole drills take away the distraction of poles, and allow us to focus on the foundational body position in our lower body that is critical to generating forward momentum with as little effort as possible. 

2. Work on your off-side: Andy is correct, working on your offside is a worthwhile task! It allows you to ski more smoothly no matter the camber of the hill you are skiing up, and it trains your arms and legs to both work when you are V1-ing. In long skis or races, or even on a long hill, switching sides can fend off cramping too. 

1. I would add-in some 1-pole skiing, (with your pole in your offside hand). Start your ski by just standing (skis off) and mimicking your V1-technique on your offside. This helps you get the timing and rhythm of a new movement. Then you can add your pole and go skiing. I would do 2-3 x 10 min one-pole within your distance ski. 

2. I like to ski a hill starting with my strong side for 1/3 of the hill, then switch to the weak side for the middle 1/3 and then back to the strong side for the top 1/3 of a hill.

3. Improve your Lower Body Position: The critical foundation of all skiing is body position. We want a nice soft flex in our ankles (dorsal flexion), and want our hips stacked over our knee and toe. This means that your hips are in a forward position (not sitting back), and your ankles are flexed into the hill. This allows us to generate almost free forward movement with very little power. Then when we apply power, it puts us in the right position to get the most forward glide out of it as possible. [if your hips are back, think sitting down or ‘riding the horse’, all our applied power goes straight down, or backwards, and we have to apply even more to actually move ourselves forward]. 

4. Upper body Position: One of the big things to avoid in V1 especially is twisting in the upper body. While there is an inherent asymmetry in the placement of your poles in order to apply power without getting all tripped up, it is NOT a twisting motion, but rather a shifting of your center of gravity from one ski to the other. Hopefully that makes sense.

Check out this video for a bit more of a visual: 

Skate Skiing World Cup V1 / Offset (Weng, Jacobsen, Kalla) #crosscountryskiing 

Specifically pay attention to: 

(1) the shin angle of each skier 

(2) forward body position, especially in hips, and using core to stabilize.   

(3) upper body rotation to apply power without twisting [bib is always facing forward, always visible, no hunching, hinging, or twisting side to side]  

Check out this link for more on V1: https://www.teamakerdahlie.com/technique/technique/#type-v1 

V2 Basics:  

V2 should be as ‘symmetrical’ as possible, applying power evenly on both sides, and gliding evenly on both sides, in order to maximize the efficiency of your skiing and glide phase. Working on your balance (which relies on the lower body position I mentioned above) is critical to being able to fully transfer your weight from ski to ski.  

Bottom line is I wouldn’t worry too much, if at all about this measurement, because it is such a small, and probably not very accurate depiction of what your technique really looks like or how effective it is. Instead focus on improving your body position and technique efficiency.