Ranger's training thread

[PaulH]

I would still like someone to demonstrate how, rowing efficiently and effectively on the erg, the force at the catch can be sustained right through to the finish, as it has been claimed is best for rowing OTW.

I know you think that's what's been claimed, but can you give us a quote where it's *actually* claimed?

Sure, that's what I _thought_ was claimed.

But, hey, if I was mistaken, that's fine with me.

Then there's no problem.

ranger

The amount of force applied in total is equal to the total area under the curve (as yo've been told many times). Theoretically a perfect rectangle as tall as possible from the start to the end of the stroke would be ideal, though clearly that's impossible. As with yours, force curves are generally loaded to the front, because that's where the strongest muscles are doing the majority of the work. Load it too much at the start, however, and you're wasting energy *otw* because of the problems with slip that have been mentioned earlier, amongst others. So it's better to apply a somewhat smaller force for a greater proportion of the stroke, rather than a larger force that diminishes more quickly. Even if the area under the two curves is the same, the flatter curve will drive a boat faster.

So yes, you were mistaken, but that doesn't mean it works as you think either.

[ranger]

Load it too much at the start, however, and you're wasting energy *otw* because of the problems with slip that have been mentioned earlier, amongst others. So it's better to apply a somewhat smaller force for a greater proportion of the stroke, rather than a larger force that diminishes more quickly. Even if the area under the two curves is the same, the flatter curve will drive a boat faster.

This is just what I would like to clarify and quantify.

But to do so, we would need to see an example, such as Mike VB's force curve.

Sure, it is possible to apply a "somewhat smaller force" at the catch, but if you do, the area under the curve as a whole will not be the same at all. As I explained, it will be about 40% less. You can overcome about half of this loss of area under the curve by jacking up the drag to max, which lengthens the drive time, and by maintaining some of the speed of leverage against the increased resistance. But even so, the area under the curve remains about 20% less, and in order to get even this modest loss in stroking power, you have had to lengthen the drive time, which cuts your ratio, and you have had to increase the resistance you have to struggle with during this increased drive time. Because of the different lengths, timings, and sequencings of the levers, unless you change your technique, this increased drive time and resistance tends to overburden the legs. You can no longer be quick and early with them, which brings a _huge_ loss in both effectiveness and efficiency. With slow legs, you do much more of the rowing with your weaker levers later on the drive, and even so, with very little rest between drives.

Rowing at 95 df., I suspect that my ratios are now _twice_ what they were when I rowed at max drag.

Rowing at 95 df., at 30 spm, where I am in a 3-to-1 ratio, my force curve comes only one inch across the PM4 screen, which is 2.75 inches long. The screen as a whole represents 1.2 seconds of drive time. That means that at 30 spm and 95 df. pulling 11 SPI, my drive time is only .43 seconds!

When I was playing around at max drag and a big sprackback finish a couple of years ago in order to try to get more stroking power, I was rowing with a drive time that was twice that.

Ratios are harmonic/geometric relations that increase and decrease in non-arithmetic ways. At 30 spm, a drive time of .5 seconds is a 3-to-1 ratio. A drive time of 1 second is a 1-to-1 ratio. If you cut the drive time in half, you triple the ratio.

ranger

[ranger]

It is a _lot_ nicer to have a base pace at 30 spm rather than 20 spm, especially if you are a 60-year-old lightweight and rowing well (13 SPI as a natural stroking power; 11 SPI for a light distance stroke), as I am.

Because you are resting most of the time, large ratios (e.g., 3-to-1) create the illusion that your rate is low and your pace slow.

They aren't!

30 spm is a _very_ high rate for distance rowing, for anyone.

And for a 60-year-old lightweight, 1:42 is blazing fast for distance rowing of any sort.

1:42 is just 1.5 seconds per 500m off of the 60 lwt 2K WR (1:40.5).

Stretched out for an 60min, which is done at top-end UT1/base pace, it is 10 seconds per 500m faster than the 60s lwt WR for the hour of rowing, in distance, 1700m, over a mile.

ranger

[jliddil]

I appreciate Ranger's interest and energy and look forward to the publication of his own work. But at this point his own results are hypothetical, and his objections to mine unfounded.

[jliddil]

And who says I am so bad OTW?

A picture is worth a thousand words.

[ranger]

And who says I am so bad OTW?

A picture is worth a thousand words.

Naw.

A picture has no temporal span and therefore is the most distorted representation of human experience imaginable, especially if it is selected to misrepresent, malign, etc.

Of course, this practice of using pictures to misrepresent and malign is common these days, as you (and Mike C.) illustrate.

Those who live in the "moment-time" of pictures are distorted, inhuman products of our very odd and peripheral cultural temporality.

ranger

[peterhowd]

Load it too much at the start, however, and you're wasting energy *otw* because of the problems with slip that have been mentioned earlier, amongst others. So it's better to apply a somewhat smaller force for a greater proportion of the stroke, rather than a larger force that diminishes more quickly. Even if the area under the two curves is the same, the flatter curve will drive a boat faster.

This is just what I would like to clarify and quantify.

But to do so, we would need to see an example, such as Mike VB's force curve.

ranger

Which is meaningless if you want to QUANTIFY his OTW propulsive force. There are far too many variables OTW that are not present on the erg. Perhaps, when you retire, you can use your considerable financial skill to fund the Brothers D to make a pair of sculling oars with imbedded pressure transducers. That might allow someone with knowledge of physics to clarify and quantify. Perhaps it has even been done?

[jliddil]

A picture is worth a thousand words.

Naw.

A picture has no temporal span

ranger

Wrong. It is short but is does span time

[jliddil]

Perhaps it has even been done?

Perhaps
http://www.ncbi.nlm.nih.gov/pubmed?term=rowing%20force

[macroth]

Aw, look at Richiepoo using big boy professor words.

Nevermind that a picture of a single stroke curve is supposed to demonstrate that this lunatic is now "rowing well" (completely different from "rowing well" he was doing years ago, mind you). No, ranger crashing out of his first OTW race on an easy course isn't evidence of anything.

[ranger]

Even at 30 spm, when my drive time contracts to .46 seconds, the peak of my force curve comes about 40% of the way through my drive.

If I were in a boat, I suspect that this would be right around when blades are square.

At 40 spm, I suspect that the peak of my force curve comes right in middle of my drive time.

I'll check it out.

ranger

[ranger]

No, at higher rates and 95 df. pulling 11 SPI, I still get a peak about 40% of the way through my drive time.

Nonetheless, this peak comes in the middle of the drive when I push with my heels and finish my legs with my hams and gluts, not at the catch when I drive off the balls of my feet, pushing with my quads.



ranger

[ranger]

No, at higher rates and 95 df. pulling 11 SPI, I still get a peak about 40% of the way through my drive time.

Nonetheless, this peak comes in the middle of the drive when I push with my heels and finish my legs with my hams and gluts, not at the catch when I drive off the balls of my feet, pushing with my quads.



ranger

[ranger]

It would be _very_ interesting, I think, to take a look at Mike VB's force curve.

ranger

[hjs]

It would be _very_ interesting, I think, to take a look at Mike VB's force curve.

ranger

You and thinking .................... not a good combination, better stop that.