SkiErg first impressions

[gvcormac]

"Cow milking" You guys crack me up!!
I'm sure the cow would not be amused!

On a more serious note....for on-snow skiers: any reason for single pole training? Variety maybe?...

I can't think of any. The original Nordic Track skier let you slide your feet back and forth thus (sort of) emulating single-pole skiing. With fixed feet there's no lower body and precious little core engagement.

[mict450]

"Cow milking" You guys crack me up!!
I'm sure the cow would not be amused!

On a more serious note....for on-snow skiers: any reason for single pole training? Variety maybe?...

I can't think of any. The original Nordic Track skier let you slide your feet back and forth thus (sort of) emulating single-pole skiing. With fixed feet there's no lower body and precious little core engagement.

Thanks! I was curious. Seems I see several uphill styles used: a diagonal stride, herringbone stride & double poling. Wild guess on my part, it would depend on the individual's strengths, and different wax jobs to exploit those strengths. BTW, I have NO experience whatsoever in OSS'ing.

[gvcormac]

Update: I tried the Workout of the Day today, which was 4x1km with 60 seconds rest. I tried cow milking for the rest, and after about 50 seconds it said "Drag factor problem ... press OK to return to main menu." And it killed my WOD.

This was before the end of the rest interval. I was planning to go back to 2-pole for the actual interval, but didn't get the chance.

[HornetMaX]

Well, it worked for the guy in the video (btw, he started with 2 double-pole strokes) so maybe it's a matter of amplitude of each stroke: his swim-like technique may have a longer stroke that is OK for the PM5 while your cow-milking may have a stroke that is too short. Possible ?

[gvcormac]

Well, it worked for the guy in the video (btw, he started with 2 double-pole strokes) so maybe it's a matter of amplitude of each stroke: his swim-like technique may have a longer stroke that is OK for the PM5 while your cow-milking may have a stroke that is too short. Possible ?

My cow milking spins the flywheel at nearly constant speed. It is not a serious stroke. In this case, I was partially just playing around, partly hoping to gain advantage with a rolling start on the next interval. I find bopping up and down (either knee or hinge) consumes a lot of energy that is not transmitted to the flywheel.

[HornetMaX]

I find bopping up and down (either knee or hinge) consumes a lot of energy that is not transmitted to the flywheel.

It is transmitted to the wheel if you're hanging when bopping down, that's the idea behind it. You put your legs, abs and back to contribution too (what you use to bop up is given back when you bop down), instead of using the arms only. On the long run, it must make a difference (but as the video shows, maybe not in extreme sprints).

[gvcormac]

I find bopping up and down (either knee or hinge) consumes a lot of energy that is not transmitted to the flywheel.

It is transmitted to the wheel if you're hanging when bopping down, that's the idea behind it. You put your legs, abs and back to contribution too (what you use to bop up is given back when you bop down), instead of using the arms only. On the long run, it must make a difference (but as the video shows, maybe not in extreme sprints).

Yes, if you put 100% of your weight on the handles, you get the energy back. But you don't, especially during recovery periods.

[HornetMaX]

Recovery periods ? What do you mean ? The weight you put on is clearly during the drive.
You're advocating something (no legs at all, no hinge at all) that is against all SkiErg tutorials I've ever seen. It's surprising.
Yes, it can be done, but it doesn't see to be the recommended way to use a SkiErg no ?

[gvcormac]

Recovery periods ? What do you mean ? The weight you put on is clearly during the drive.
You're advocating something (no legs at all, no hinge at all) that is against all SkiErg tutorials I've ever seen. It's surprising.
Yes, it can be done, but it doesn't see to be the recommended way to use a SkiErg no ?

The word recovery is overloaded. When you do intervals, the rest period between intervals is called "recovery." So is returning from the stroke. I meant the former.

I'm not advocating cow milking. I did it as an experiment to explore the psyche of the PM5.

As for what I actually do in anger, I use primarily hip hinge. Minimal knee bend and no heel lift. A bit of arm straightening at the bottom of the stroke. That's what minimizes energy expenditure for me. For a sprint, overall energy expenditure is less important, and deeper knee bends and raised heels may be an advantage.

[HornetMaX]

Ah OK, makes more sense, recovery as in rest intervals.

[gvcormac]

The hinge discussion has prompted me to do another experiment: Ski Erging while standing on a bathroom scale. I'm not sure if the scale responds fast enough to get more than a vague impression, but the idea is to compare weight during the stroke with weight during recovery, compared to static weight. You really need to integrate these over time, but perhaps one can get an idea of the peak magnitude in each direction.

I wonder where I could round up a scale with digital output ...

[Ombrax]

The hinge discussion has prompted me to do another experiment: Ski Erging while standing on a bathroom scale. I'm not sure if the scale responds fast enough to get more than a vague impression, but the idea is to compare weight during the stroke with weight during recovery, compared to static weight. You really need to integrate these over time, but perhaps one can get an idea of the peak magnitude in each direction.

I wonder where I could round up a scale with digital output ...

This seems relevant to your idea:

https://www.analog.com/en/analog-dialog ... cales.html

[HornetMaX]

The hinge discussion has prompted me to do another experiment: Ski Erging while standing on a bathroom scale. I'm not sure if the scale responds fast enough to get more than a vague impression, but the idea is to compare weight during the stroke with weight during recovery, compared to static weight. You really need to integrate these over time, but perhaps one can get an idea of the peak magnitude in each direction.

I wonder where I could round up a scale with digital output ...

But what are you hoping to measure with that ?

Because assuming one trusts what the PM5 does (in terms of measure of force or power), then you have all you need.
The work you put in is (minus minor things like friction and hysteresis) what the PM5 sees.
Hinging / bending the knees / lifting the heels are only a way to do part of that work with different muscles (instead of arms only).

[gvcormac]

The hinge discussion has prompted me to do another experiment: Ski Erging while standing on a bathroom scale. I'm not sure if the scale responds fast enough to get more than a vague impression, but the idea is to compare weight during the stroke with weight during recovery, compared to static weight. You really need to integrate these over time, but perhaps one can get an idea of the peak magnitude in each direction.

I wonder where I could round up a scale with digital output ...

But what are you hoping to measure with that ?

Because assuming one trusts what the PM5 does (in terms of measure of force or power), then you have all you need.
The work you put in is (minus minor things like friction and hysteresis) what the PM5 sees.
Hinging / bending the knees / lifting the heels are only a way to do part of that work with different muscles (instead of arms only).

Let's take the SkiErg out of the equation. If you do squats and/or hinges you will use energy raising your body, and that energy will be wasted as heat when you lower your body. Now pull on the SkiErg handles when lowering. Some of the energy that would otherwise be wasted will be transferred to the SkiErg. You can measure the amount by how much your apparent weight is decreased when you pull on the SkiErg. It gets a bit more complicated than that because work is force times distance, so you need to figure out how far up and down you are moving. But it would be a start. So long as your apparent weight is greater than zero (or maybe greater than the weight of the non-moving part of your body) you are wasting some of your lift. The goal is to minimize your apparent weight during the stroke, so as to maximize energy transfer to the machine.

The RowErg also involves waste energy, but its on the horizontal plane, so not as large -- just the kinetic energy you develop in recovery, not energy from lifting a heavy weight (you). If I recall correctly, studies have shown this waste to be between 10% and 20%.

The BikeErg has the least waste of all. A bit from the recipricating weight of one shin and 1/2 thigh at a time.

[gvcormac]

The hinge discussion has prompted me to do another experiment: Ski Erging while standing on a bathroom scale. I'm not sure if the scale responds fast enough to get more than a vague impression, but the idea is to compare weight during the stroke with weight during recovery, compared to static weight. You really need to integrate these over time, but perhaps one can get an idea of the peak magnitude in each direction.

I wonder where I could round up a scale with digital output ...

This seems relevant to your idea:

https://www.analog.com/en/analog-dialog ... cales.html

Indeed. Now if we had a commodity-priced implementation with USB or Bluetooth data stream we'd be in business.